Science.gov

Sample records for advanced crash avoidance

  1. Millimeter wave radar for automobile crash avoidance systems

    NASA Astrophysics Data System (ADS)

    Huguenin, G. Richard

    1994-08-01

    Low cost, millimeter wave, forward looking radar sensors for applications in Autonomous Collision Warning and Autonomous Intelligent Cruise Control systems will be described. These safety related systems promise the largest payoff in preventing highway crashes.

  2. What do cyclists need to see to avoid single-bicycle crashes?

    PubMed

    Schepers, Paul; den Brinker, Berry

    2011-04-01

    The number of single-bicycle crash victims is substantial in countries with high levels of cycling. To study the role of visual characteristics of the infrastructure, such as pavement markings, in single-bicycle crashes, a study in two steps was conducted. In Study 1, a questionnaire study was conducted among bicycle crash victims (n = 734). Logistic regression was used to study the relationship between the crashes and age, light condition, alcohol use, gaze direction and familiarity with the crash scene. In Study 2, the image degrading and edge detection method (IDED-method) was used to investigate the visual characteristics of 21 of the crash scenes. The results of the studies indicate that crashes, in which the cyclist collided with a bollard or road narrowing or rode off the road, were related to the visual characteristics of bicycle facilities. Edge markings, especially in curves of bicycle tracks, and improved conspicuity of bollards are recommended. STATEMENT OF RELEVANCE: Elevated single-bicycle crash numbers are common in countries with high levels of cycling. No research has been conducted on what cyclists need to see to avoid this type of crash. The IDED-method to investigate crash scenes is new and proves to be a powerful tool to quantify 'visual accessibility'. PMID:21491274

  3. Advanced Fuzzy Potential Field Method for Mobile Robot Obstacle Avoidance

    PubMed Central

    Park, Jong-Wook; Kwak, Hwan-Joo; Kang, Young-Chang; Kim, Dong W.

    2016-01-01

    An advanced fuzzy potential field method for mobile robot obstacle avoidance is proposed. The potential field method primarily deals with the repulsive forces surrounding obstacles, while fuzzy control logic focuses on fuzzy rules that handle linguistic variables and describe the knowledge of experts. The design of a fuzzy controller—advanced fuzzy potential field method (AFPFM)—that models and enhances the conventional potential field method is proposed and discussed. This study also examines the rule-explosion problem of conventional fuzzy logic and assesses the performance of our proposed AFPFM through simulations carried out using a mobile robot. PMID:27123001

  4. Advanced Fuzzy Potential Field Method for Mobile Robot Obstacle Avoidance.

    PubMed

    Park, Jong-Wook; Kwak, Hwan-Joo; Kang, Young-Chang; Kim, Dong W

    2016-01-01

    An advanced fuzzy potential field method for mobile robot obstacle avoidance is proposed. The potential field method primarily deals with the repulsive forces surrounding obstacles, while fuzzy control logic focuses on fuzzy rules that handle linguistic variables and describe the knowledge of experts. The design of a fuzzy controller--advanced fuzzy potential field method (AFPFM)--that models and enhances the conventional potential field method is proposed and discussed. This study also examines the rule-explosion problem of conventional fuzzy logic and assesses the performance of our proposed AFPFM through simulations carried out using a mobile robot. PMID:27123001

  5. Advancing age progressively affects obstacle avoidance skills in the elderly.

    PubMed

    Weerdesteyn, Vivian; Nienhuis, Bart; Duysens, Jacques

    2005-01-01

    The ability to adequately avoid obstacles while walking is an important skill that allows safe locomotion over uneven terrain. The high proportion of falls in the elderly that is associated to tripping over obstacles potentially illustrates an age-related deterioration of this locomotor skill. Some studies have compared young and old adults, but very little is known about the changes occurring within different age groups of elderly. In the present study, obstacle avoidance performance was studied in 25 young (20-37 years) and 99 older adults (65-88 years). The participants walked on a treadmill at a speed of 3 km/h. An obstacle was dropped 30 times in front of the left foot at various phases in the step cycle. Success rates (successful avoidance) were calculated and related to the time available between obstacle appearance and the estimated instant of foot contact with the obstacle (available response times or ARTs ranging from 200 to more than 350 ms). In addition, latencies of avoidance reactions, the choice of avoidance strategies (long or short step strategy, LSS or SSS), and three spatial parameters related to obstacle avoidance (toe distance, foot clearance, and heel distance) were determined for each participant. Compared to the young, the older adults had lower success rates, especially at short ARTs. Furthermore, they had longer reaction times, more LSS reactions, smaller toe and heel distances, and larger foot clearances. Within the group of elderly, only the 65-69 year olds were not different from young adults with respect to success rate, despite marked changes in the other parameters measured. In particular, even this younger group of elderly showed a dramatic reduction in the amount of SSS trials compared to young adults. Overall, age was a significant predictor of success rates, reaction times, and toe distances. These parameters deteriorated with advancing age. Finally, avoidance success rates at short ARTs were considerably worse in elderly

  6. Sikorski - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Roof instrument panel between pilot stations, right view. Photographed at the Impact Dynamics Research Facility, building 1297.

  7. Sikorski - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Roof instrument panel between pilot stations - left view. Photographed at the Impact Dynamics Research Facility, building 1297.

  8. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Sub-floor, inside view showing details of limited crushing. Photographed at the Impact Dynamics Research Facility, building 1297.

  9. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Left view of cockpit showing manikin head against panel. Photographed at the Impact Dynamics Research Facility, building 1297.

  10. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Right view of cabin showing troop seat fabric failure. Photographed at the Impact Dynamics Research Facility, building 1297.

  11. Crash Models for Advanced Automotive Batteries: A Review of the Current State of the Art

    SciTech Connect

    Turner, John A.; Allu, Srikanth; Gorti, Sarma B.; Kalnaus, Sergiy; Kumar, Abhishek; Lebrun-Grandie, Damien T.; Pannala, Sreekanth; Simunovic, Srdjan; Slattery, Stuart R.; Wang, Hsin

    2015-02-01

    Safety is a critical aspect of lithium-ion (Li-ion) battery design. Impact/crash conditions can trigger a complex interplay of mechanical contact, heat generation and electrical discharge, which can result in adverse thermal events. The cause of these thermal events has been linked to internal contact between the opposite electrodes, i.e. internal short circuit. The severity of the outcome is influenced by the configuration of the internal short circuit and the battery state. Different loading conditions and battery states may lead to micro (soft) shorts where material burnout due to generated heat eliminates contact between the electrodes, or persistent (hard) shorts which can lead to more significant thermal events and potentially damage the entire battery system and beyond. Experimental characterization of individual battery components for the onset of internal shorts is limited, since it is impractical to canvas all possible variations in battery state of charge, operating conditions, and impact loading in a timely manner. This report provides a survey of modeling and simulation approaches and documents a project initiated and funded by DOT/NHTSA to improve modeling and simulation capabilities in order to design tests that provide leading indicators of failure in batteries. In this project, ORNL has demonstrated a computational infrastructure to conduct impact simulations of Li-ion batteries using models that resolve internal structures and electro-thermo-chemical and mechanical conditions. Initial comparisons to abuse experiments on cells and cell strings conducted at ORNL and Naval Surface Warfare Center (NSWC) at Carderock MD for parameter estimation and model validation have been performed. This research has provided insight into the mechanisms of deformation in batteries (both at cell and electrode level) and their relationship to the safety of batteries.

  12. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Top view from gantry, showing helicopter in final position after sliding 23 feet from initial impact. Photographed at the Impact Dynamics Research Facility, building 1297.

  13. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Sub-floor, inside view between station 175 and 143, showing limited crushing. Photographed at the Impact Dynamics Research Facility, building 1297.

  14. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Overall view of the nose landing gear (originally from Sikorsky S-76 helicopter). Photographed at the Impact Dynamics Research Facility, building 1297.

  15. Utilizing the eigenvectors of freeway loop data spatiotemporal schematic for real time crash prediction.

    PubMed

    Fang, Shou'en; Xie, Wenjing; Wang, Junhua; Ragland, David R

    2016-09-01

    The concept of crash precursor identification is gaining more practicality due to the recent advancements in Advanced Transportation Management and Information Systems. Investigating the shortcomings of the existing models, this paper proposes a new method to model the real time crash likelihood based on loop data through schematic eigenvectors. Firstly, traffic volume, occupancy and density spatiotemporal schematics in certain duration before an accident occurrence were constructed to describe the traffic flow status. Secondly, eigenvectors and eigenvalues of the spatiotemporal schematics were extracted to represent traffic volume, occupancy and density situation before the crash occurrence. Thirdly, by setting the vectors in crash time as case and those at crash free time as control, a logistic model is constructed to identify the crash precursors. Results show that both the eigenvectors and eigenvalues can significantly impact the accident likelihood compared to the previous study, the proposed model has the advantage of avoiding multicollinearity, better reflection of the overall traffic flow status before the crash, and improving missing data problem of loop detectors.

  16. Utilizing the eigenvectors of freeway loop data spatiotemporal schematic for real time crash prediction.

    PubMed

    Fang, Shou'en; Xie, Wenjing; Wang, Junhua; Ragland, David R

    2016-09-01

    The concept of crash precursor identification is gaining more practicality due to the recent advancements in Advanced Transportation Management and Information Systems. Investigating the shortcomings of the existing models, this paper proposes a new method to model the real time crash likelihood based on loop data through schematic eigenvectors. Firstly, traffic volume, occupancy and density spatiotemporal schematics in certain duration before an accident occurrence were constructed to describe the traffic flow status. Secondly, eigenvectors and eigenvalues of the spatiotemporal schematics were extracted to represent traffic volume, occupancy and density situation before the crash occurrence. Thirdly, by setting the vectors in crash time as case and those at crash free time as control, a logistic model is constructed to identify the crash precursors. Results show that both the eigenvectors and eigenvalues can significantly impact the accident likelihood compared to the previous study, the proposed model has the advantage of avoiding multicollinearity, better reflection of the overall traffic flow status before the crash, and improving missing data problem of loop detectors. PMID:27258946

  17. Emerging technology for vehicular safety and emergency response to roadway crashes.

    PubMed

    Champion, H R; Cushing, B

    1999-12-01

    Emerging technology for vehicular safety and emergency response to roadway crashes is the topic of this article. Reduction in emergency medical services system notification time, improvements in vehicular safety, crash avoidance and protection, post-crash injury control, triage, national automatic crash notification systems, and technologic improvements in emergency diagnostics and treatment during the past year are discussed. PMID:10625974

  18. Crash reconstruction and crash modification factors.

    PubMed

    Davis, Gary A

    2014-01-01

    This paper addresses the following question: Under what conditions can reconstructed road crashes be used to estimate the effect of a safety-related countermeasure? Results developed by Pearl and his associates are used to draw two main conclusions. First, when one can (1) identify a structural equation describing a type of crash, (2) identify an additional structural equation describing the countermeasure's impact, and (3) estimate the initiating conditions for a set of reconstructed crashes, then a lower bound for a crash modification factor can be estimated by simulating whether or not each of the reconstructed crashes would still have occurred had the countermeasure been present. If the countermeasure's effect is monotonic this bound becomes tight. Second, in situations where it is not possible to reliably identify the structural equations needed for simulation, but where one can (1) identify a set of crash inputs which, when given, make the crash outcome conditionally independent of the countermeasure, and (2) predict how the distribution of these inputs will change in response to the countermeasure, then nonparametric estimation of the countermeasure's crash modification factor is possible. When it is not possible to predict the countermeasure's effect on the conditioning variables it may still be possible to identify constraints or specifications which the countermeasure should satisfy in order to realize a target crash modification.

  19. Attributions of responsibility for motor vehicle crashes.

    PubMed

    Stewart, Alan E

    2005-07-01

    A sample of 321 motor vehicle crash survivors completed a survey in which they provided attribution ratings of the extent to which they were responsible for their crashes, other people (drivers) were responsible, or road/weather conditions were responsible. The attribution ratings were consistent with the predictions of defensive attribution theory (DAT; [Walster, E., 1966. Assignment of responsibility for an accident. J. Pers. Soc. Psychol. 3, 73-79]) in that people who experienced crashes of greater severity (necessitating medical treatment for injuries) attributed greater responsibility to other drivers than to self or to weather/road conditions. People who were in crashes of lesser severity attributed approximately the same amount of responsibility to themselves as they did to others. An actor-observer effect also appeared in survivors' attribution ratings in that self-acceptance of responsibility for the crash was positively correlated with attributions to the situation (road/weather conditions) whereas such attributions to the situation were negatively correlated with attributions of responsibility to other drivers. Consistent with results of prior research, survivors who assigned crash responsibility to other drivers reported increased levels of driving and riding avoidance compared to people who accepted responsibility for their crashes.

  20. Technical Seminar: "Crash Safety"""

    NASA Video Gallery

    This seminar addresses the history and successful progress in predicting and improving the crash safety characteristics of vehicles, with particular emphasis on rotary wing aircraft and composite s...

  1. Hubble Witnesses Comet Crash

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Quick Time Movie for PIA02122 Hubble Witnesses Comet Crash

    [figure removed for brevity, see original site] Figure 1: Hubble Witnesses Comet Crash

    These pictures of comet Tempel 1 were taken by NASA's Hubble Space Telescope. They show the comet before and after it ran over NASA's Deep Impact probe.

  2. Advanced emergency braking controller design for pedestrian protection oriented automotive collision avoidance system.

    PubMed

    Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

    2014-01-01

    Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian. PMID:25097870

  3. Advanced emergency braking controller design for pedestrian protection oriented automotive collision avoidance system.

    PubMed

    Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

    2014-01-01

    Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian.

  4. Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System

    PubMed Central

    Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

    2014-01-01

    Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian. PMID:25097870

  5. Best Practices for Crash Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Jackson, Karen E.

    2002-01-01

    Aviation safety can be greatly enhanced by the expeditious use of computer simulations of crash impact. Unlike automotive impact testing, which is now routine, experimental crash tests of even small aircraft are expensive and complex due to the high cost of the aircraft and the myriad of crash impact conditions that must be considered. Ultimately, the goal is to utilize full-scale crash simulations of aircraft for design evaluation and certification. The objective of this publication is to describe "best practices" for modeling aircraft impact using explicit nonlinear dynamic finite element codes such as LS-DYNA, DYNA3D, and MSC.Dytran. Although "best practices" is somewhat relative, it is hoped that the authors' experience will help others to avoid some of the common pitfalls in modeling that are not documented in one single publication. In addition, a discussion of experimental data analysis, digital filtering, and test-analysis correlation is provided. Finally, some examples of aircraft crash simulations are described in several appendices following the main report.

  6. Critical market crashes

    NASA Astrophysics Data System (ADS)

    Sornette, D.

    2003-04-01

    This review presents a general theory of financial crashes and of stock market instabilities that his co-workers and the author have developed over the past seven years. We start by discussing the limitation of standard analyses for characterizing how crashes are special. The study of the frequency distribution of drawdowns, or runs of successive losses shows that large financial crashes are “outliers”: they form a class of their own as can be seen from their statistical signatures. If large financial crashes are “outliers”, they are special and thus require a special explanation, a specific model, a theory of their own. In addition, their special properties may perhaps be used for their prediction. The main mechanisms leading to positive feedbacks, i.e., self-reinforcement, such as imitative behavior and herding between investors are reviewed with many references provided to the relevant literature outside the narrow confine of Physics. Positive feedbacks provide the fuel for the development of speculative bubbles, preparing the instability for a major crash. We demonstrate several detailed mathematical models of speculative bubbles and crashes. A first model posits that the crash hazard drives the market price. The crash hazard may sky-rocket at some times due to the collective behavior of “noise traders”, those who act on little information, even if they think they “know”. A second version inverses the logic and posits that prices drive the crash hazard. Prices may skyrocket at some times again due to the speculative or imitative behavior of investors. According the rational expectation model, this entails automatically a corresponding increase of the probability for a crash. We also review two other models including the competition between imitation and contrarian behavior and between value investors and technical analysts. The most important message is the discovery of robust and universal signatures of the approach to crashes. These precursory

  7. Relating crash frequency and severity: evaluating the effectiveness of shoulder rumble strips on reducing fatal and major injury crashes.

    PubMed

    Wu, Kun-Feng; Donnell, Eric T; Aguero-Valverde, Jonathan

    2014-06-01

    To approach the goal of "Toward Zero Deaths," there is a need to develop an analysis paradigm to better understand the effects of a countermeasure on reducing the number of severe crashes. One of the goals in traffic safety research is to search for an effective treatment to reduce fatal and major injury crashes, referred to as severe crashes. To achieve this goal, the selection of promising countermeasures is of utmost importance, and relies on the effectiveness of candidate countermeasures in reducing severe crashes. Although it is important to precisely evaluate the effectiveness of candidate countermeasures in reducing the number of severe crashes at a site, the current state-of-the-practice often leads to biased estimates. While there have been a few advanced statistical models developed to mitigate the problem in practice, these models are computationally difficult to estimate because severe crashes are dispersed spatially and temporally, and cannot be integrated into the Highway Safety Manual framework, which develops a series of safety performance functions and crash modification factors to predict the number of crashes. Crash severity outcomes are generally integrated into the Highway Safety Manual using deterministic distributions rather than statistical models. Accounting for the variability in crash severity as a function geometric design, traffic flow, and other roadway and roadside features is afforded by estimating statistical models. Therefore, there is a need to develop a new analysis paradigm to resolve the limitations in the current Highway Safety Manual methods. We propose an approach which decomposes the severe crash frequency into a function of the change in the total number of crashes and the probability of a crash becoming a severe crash before and after a countermeasure is implemented. We tested this approach by evaluating the effectiveness of shoulder rumble strips on reducing the number of severe crashes. A total of 310 segments that have

  8. Crash and Creativeness in Education

    ERIC Educational Resources Information Center

    Punke, Harold H.

    1977-01-01

    American patterns of cultural growth are sometimes said to be characterized by "crash programs"--indifference or neglect followed by a crash emphasis on air and water pollution, urban decay and ghettos, population growth, etc. Considers the neglect-and-crash approach as it relates to three areas within the field of education. (Author/RK)

  9. Avoiding obsolescence in advanced prostate cancer management: a guide for urologists.

    PubMed

    Shore, Neal D; Karsh, Lawrence; Gomella, Leonard G; Keane, Thomas E; Concepcion, Raoul S; Crawford, E David

    2015-02-01

    Prostate cancer is one of the most common cancers diagnosed in men in the USA and 20–30% of men treated for localised prostate cancer will fail therapy and develop advanced prostate cancer. More drugs have been approved for the treatment of advanced prostate cancer in the past 3 years than in the past three decades, and each drug has its own mechanism of action and, often, unique monitoring requirements. As the treatment landscape for men with advanced prostate cancer is undergoing significant expansion, the roles of both oncologists and urologists are shifting, and the decision for the urologist to treat vs refer requires early assessment to identify which patients are candidates for these novel treatments and the monitoring of patients for tolerability, response, and potential side-effects. Given these rapid changes, the authors of this review met in January 2013 and again in April 2013 to discuss the current challenges facing urologists in adopting these new treatments into their own practices. Here, we provide a brief overview of advanced prostate cancer medical therapies approved in the past decade, the necessary monitoring procedures and early detection methods needed to safely and effectively manage patients receiving these therapies, and our recommendations for applying these new therapies within different models of urology practice, such that urologists can remain an integral component of their patient's care once he has transitioned into advanced prostate cancer

  10. Avoiding obsolescence in advanced prostate cancer management: a guide for urologists.

    PubMed

    Shore, Neal D; Karsh, Lawrence; Gomella, Leonard G; Keane, Thomas E; Concepcion, Raoul S; Crawford, E David

    2015-02-01

    Prostate cancer is one of the most common cancers diagnosed in men in the USA and 20–30% of men treated for localised prostate cancer will fail therapy and develop advanced prostate cancer. More drugs have been approved for the treatment of advanced prostate cancer in the past 3 years than in the past three decades, and each drug has its own mechanism of action and, often, unique monitoring requirements. As the treatment landscape for men with advanced prostate cancer is undergoing significant expansion, the roles of both oncologists and urologists are shifting, and the decision for the urologist to treat vs refer requires early assessment to identify which patients are candidates for these novel treatments and the monitoring of patients for tolerability, response, and potential side-effects. Given these rapid changes, the authors of this review met in January 2013 and again in April 2013 to discuss the current challenges facing urologists in adopting these new treatments into their own practices. Here, we provide a brief overview of advanced prostate cancer medical therapies approved in the past decade, the necessary monitoring procedures and early detection methods needed to safely and effectively manage patients receiving these therapies, and our recommendations for applying these new therapies within different models of urology practice, such that urologists can remain an integral component of their patient's care once he has transitioned into advanced prostate cancer PMID:25756134

  11. Polar bears (Ursus maritimus), the most evolutionary advanced hibernators, avoid significant bone loss during hibernation.

    PubMed

    Lennox, Alanda R; Goodship, Allen E

    2008-02-01

    Some hibernating animals are known to reduce muscle and bone loss associated with mechanical unloading during prolonged immobilisation,compared to humans. However, here we show that wild pregnant polar bears (Ursus maritimus) are the first known animals to avoid significant bone loss altogether, despite six months of continuous hibernation. Using serum biochemical markers of bone turnover, we showed that concentrations for bone resorption are not significantly increased as a consequence of hibernation in wild polar bears. This is in sharp contrast to previous studies on other hibernating species, where for example, black bears (Ursus americanus), show a 3-4 fold increase in serum bone resorption concentrations posthibernation,and must compensate for this loss through rapid bone recovery on remobilisation, to avoid the risk of fracture. In further contrast to black bears, serum concentrations of bone formation markers were highly significantly increased in pregnant female polar bears compared to non-pregnant,thus non-hibernating females both prior to and after hibernation. However, bone formation concentrations in new mothers were significantly reduced compared to pre-hibernation concentrations. The de-coupling of bone turnover in favour of bone formation prior to hibernation, suggests that wild polar bears may posses a unique physiological mechanism for building bone in protective preparation against expected osteopenia associated with disuse,starvation, and hormonal drives to mobilise calcium for reproduction, during hibernation. Understanding this physiological mechanism could have profound implications for a natural solution for the prevention of osteoporosis in animals subjected to captivity with inadequate space for exercise,humans subjected to prolonged bed rest while recovering from illness, or astronauts exposed to antigravity during spaceflight.© 2008 Elsevier Inc. All rights reserved. PMID:18249018

  12. Bicycling crash characteristics: An in-depth crash investigation study.

    PubMed

    Beck, Ben; Stevenson, Mark; Newstead, Stuart; Cameron, Peter; Judson, Rodney; Edwards, Elton R; Bucknill, Andrew; Johnson, Marilyn; Gabbe, Belinda

    2016-11-01

    The aim of this study was to describe the crash characteristics and patient outcomes of a sample of patients admitted to hospital following bicycle crashes. Injured cyclists were recruited from the two major trauma services for the state of Victoria, Australia. Enrolled cyclists completed a structured interview, and injury details and patient outcomes were extracted from the Victorian State Trauma Registry (VSTR) and the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). 186 cyclists consented to participate in the study. Crashes commonly occurred during daylight hours and in clear weather conditions. Two-thirds of crashes occurred on-road (69%) and were a combination of single cyclist-only events (56%) and multi-vehicle crashes (44%). Of the multi-vehicle crashes, a motor vehicle was the most common impact partner (72%) and distinct pre-crash directional interactions were observed between the cyclist and motor vehicle. Nearly a quarter of on-road crashes occurred when the cyclist was in a marked bicycle lane. Of the 31% of crashes that were not on-road, 28 (15%) occurred on bicycle paths and 29 (16%) occurred in other locations. Crashes on bicycle paths commonly occurred on shared bicycle and pedestrian paths (83%) and did not involve another person or vehicle. Other crash locations included mountain bike trails (39%), BMX parks (21%) and footpaths (18%). While differences in impact partners and crash characteristics were observed between crashes occurring on-road, on bicycle paths and in other locations, injury patterns and severity were similar. Most cyclists had returned to work at 6 months post-injury, however only a third of participants reported a complete functional recovery. Further research is required to develop targeted countermeasures to address the risk factors identified in this study. PMID:27544886

  13. Bicycling crash characteristics: An in-depth crash investigation study.

    PubMed

    Beck, Ben; Stevenson, Mark; Newstead, Stuart; Cameron, Peter; Judson, Rodney; Edwards, Elton R; Bucknill, Andrew; Johnson, Marilyn; Gabbe, Belinda

    2016-11-01

    The aim of this study was to describe the crash characteristics and patient outcomes of a sample of patients admitted to hospital following bicycle crashes. Injured cyclists were recruited from the two major trauma services for the state of Victoria, Australia. Enrolled cyclists completed a structured interview, and injury details and patient outcomes were extracted from the Victorian State Trauma Registry (VSTR) and the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). 186 cyclists consented to participate in the study. Crashes commonly occurred during daylight hours and in clear weather conditions. Two-thirds of crashes occurred on-road (69%) and were a combination of single cyclist-only events (56%) and multi-vehicle crashes (44%). Of the multi-vehicle crashes, a motor vehicle was the most common impact partner (72%) and distinct pre-crash directional interactions were observed between the cyclist and motor vehicle. Nearly a quarter of on-road crashes occurred when the cyclist was in a marked bicycle lane. Of the 31% of crashes that were not on-road, 28 (15%) occurred on bicycle paths and 29 (16%) occurred in other locations. Crashes on bicycle paths commonly occurred on shared bicycle and pedestrian paths (83%) and did not involve another person or vehicle. Other crash locations included mountain bike trails (39%), BMX parks (21%) and footpaths (18%). While differences in impact partners and crash characteristics were observed between crashes occurring on-road, on bicycle paths and in other locations, injury patterns and severity were similar. Most cyclists had returned to work at 6 months post-injury, however only a third of participants reported a complete functional recovery. Further research is required to develop targeted countermeasures to address the risk factors identified in this study.

  14. Advanced Whale Detection Methods to Improve Whale-Ship Collision Avoidance

    NASA Astrophysics Data System (ADS)

    McGillivary, P. A.; Tougher, B.

    2010-12-01

    Collisions between whales and ships are now estimated to account for fully a third of all whale deaths worldwide. Such collisions can incur costly ship repairs, and may damage or disable ship steering requiring costly response efforts from state and federal agencies. While collisions with rare whale species are problematic in further reducing their low population numbers, collisions with some of the more abundant whale species are also becoming more common as their populations increase. The problem is compounded as ship traffic likewise continues to grow, thus posing a growing risk to both whales and ships. Federal agencies are considering policies to alter shipping lanes to minimize whale-ship collisions off California and elsewhere. Similar efforts have already been undertaken for the Boston Harbor ship approach, where a bend in the shipping lane was introduced to reduce ship traffic through a favorite area of the highly endangered North Atlantic Right Whale. The Boston shipping approach lane was also flanked with a system of moorings with whale detection hydrophones which broadcast the presence of calling whales in or near the ship channel to approaching ships in real time. When so notified, ships can post lookouts to avoid whale collisions, and reduce speed to reduce the likelihood of whale death, which is highly speed dependent. To reduce the likelihood and seriousness of whale-ship collisions off California and Alaska in particular, there is a need to better know areas of particularly high use by whales, and consider implementation of reduced ship speeds in these areas. There is also an ongoing discussion of altering shipping lanes in the Santa Barbara Channel to avoid habitual Blue whales aggregation areas in particular. However, unlike the case for Boston Harbor, notification of ships that whales are nearby to reduce or avoid collisions is complicated because many California and Alaska whale species do not call regularly, and would thus be undetected by

  15. Reading as Wedding Crashing

    ERIC Educational Resources Information Center

    Newkirk, Thomas

    2014-01-01

    Grappling with difficult texts can make readers feel as though they're crashing a party that wasn't meant for them. They don't know the occasion. They don't know the guests. They have a hard time fitting in. In this article, Thomas Newkirk suggests several reasons why students find texts difficult to understand. Students may be…

  16. Evaluation of rear-end crash risk at work zone using work zone traffic data.

    PubMed

    Meng, Qiang; Weng, Jinxian

    2011-07-01

    This paper aims to evaluate the rear-end crash risk at work zone activity area and merging area, as well as analyze the impacts of contributing factors by using work zone traffic data. Here, the rear-end crash risk is referred to as the probability that a vehicle is involved in a rear-end crash accident. The deceleration rate to avoid the crash (DRAC) is used in measuring rear-end crash risk. Based on work zone traffic data in Singapore, three rear-end crash risk models are developed to examine the relationship between rear-end crash risk at activity area and its contributing factors. The fourth rear-end crash risk model is developed to examine the effects of merging behavior on crash risk at merging area. The ANOVA results show that the rear-end crash risk at work zone activity area is statistically different from lane positions. Model results indicate that rear-end crash risk at work zone activity area increases with heavy vehicle percentage and lane traffic flow rate. An interesting finding is that the lane closer to work zone is strongly associated with higher rear-end crash risk. A truck has much higher probability involving in a rear-end accident than a car. Further, the expressway work zone activity area is found to have much larger crash risk than arterial work zone activity area. The merging choice has the dominated effect on risk reduction, suggesting that encouraging vehicles to merge early may be the most effective method to reduce rear-end crash risk at work zone merging area.

  17. Resisting "Crash Diet" Staff Development

    ERIC Educational Resources Information Center

    Dana, Nancy Fichtman; Yendol-Hoppey, Diane

    2008-01-01

    People often respond to the pressure of attending a high school reunion or their child's wedding by going on a crash diet to get quick results. In response, friends may marvel about how good they look on the outside. But what folks don't acknowledge is that, in the name of getting results, crash dieters have done some very unhealthy things to…

  18. Analysis of work zone rear-end crash risk for different vehicle-following patterns.

    PubMed

    Weng, Jinxian; Meng, Qiang; Yan, Xuedong

    2014-11-01

    This study evaluates rear-end crash risk associated with work zone operations for four different vehicle-following patterns: car-car, car-truck, truck-car and truck-truck. The deceleration rate to avoid the crash (DRAC) is adopted to measure work zone rear-end crash risk. Results show that the car-truck following pattern has the largest rear-end crash risk, followed by truck-truck, truck-car and car-car patterns. This implies that it is more likely for a car which is following a truck to be involved in a rear-end crash accident. The statistical test results further confirm that rear-end crash risk is statistically different between any two of the four patterns. We therefore develop a rear-end crash risk model for each vehicle-following pattern in order to examine the relationship between rear-end crash risk and its influencing factors, including lane position, the heavy vehicle percentage, lane traffic flow and work intensity which can be characterized by the number of lane reductions, the number of workers and the amount of equipment at the work zone site. The model results show that, for each pattern, there will be a greater rear-end crash risk in the following situations: (i) heavy work intensity; (ii) the lane adjacent to work zone; (iii) a higher proportion of heavy vehicles and (iv) greater traffic flow. However, the effects of these factors on rear-end crash risk are found to vary according to the vehicle-following patterns. Compared with the car-car pattern, lane position has less effect on rear-end crash risk in the car-truck pattern. The effect of work intensity on rear-end crash risk is also reduced in the truck-car pattern.

  19. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes.

    PubMed

    Kusano, Kristofer D; Gabler, Hampton C

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G's to 0.8 G's while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G's. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% - 50% and avoid 0% - 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%.

  20. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes.

    PubMed

    Kusano, Kristofer D; Gabler, Hampton C

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G's to 0.8 G's while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G's. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% - 50% and avoid 0% - 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%. PMID:21050603

  1. Distracted Driving Raises Crash Risk

    MedlinePlus

    ... Raises Crash Risk Video technology and in-vehicle sensors showed that distracted driving, especially among new drivers, ... whenever the cars were moving. A suite of sensors recorded acceleration, sudden braking or swerving, and other ...

  2. Intelligent geocoding system to locate traffic crashes.

    PubMed

    Qin, Xiao; Parker, Steven; Liu, Yi; Graettinger, Andrew J; Forde, Susie

    2013-01-01

    State agencies continue to face many challenges associated with new federal crash safety and highway performance monitoring requirements that use data from multiple and disparate systems across different platforms and locations. On a national level, the federal government has a long-term vision for State Departments of Transportation (DOTs) to report state route and off-state route crash data in a single network. In general, crashes occurring on state-owned or state maintained highways are a priority at the Federal and State level; therefore, state-route crashes are being geocoded by state DOTs. On the other hand, crashes occurring on off-state highway system do not always get geocoded due to limited resources and techniques. Creating and maintaining a statewide crash geographic information systems (GIS) map with state route and non-state route crashes is a complicated and expensive task. This study introduces an automatic crash mapping process, Crash-Mapping Automation Tool (C-MAT), where an algorithm translates location information from a police report crash record to a geospatial map and creates a pinpoint map for all crashes. The algorithm has approximate 83 percent mapping rate. An important application of this work is the ability to associate the mapped crash records to underlying business data, such as roadway inventory and traffic volumes. The integrated crash map is the foundation for effective and efficient crash analyzes to prevent highway crashes. PMID:22921783

  3. "Crashing the gates" - selection criteria for television news reporting of traffic crashes.

    PubMed

    De Ceunynck, Tim; De Smedt, Julie; Daniels, Stijn; Wouters, Ruud; Baets, Michèle

    2015-07-01

    This study investigates which crash characteristics influence the probability that the crash is reported in the television news. To this purpose, all news items from the period 2006-2012 about traffic crashes from the prime time news of two Belgian television channels are linked to the official injury crash database. Logistic regression models are built for the database of all injury crashes and for the subset of fatal crashes to identify crash characteristics that correlate with a lower or higher probability of being reported in the news. A number of significant biases in terms of crash severity, time, place, types of involved road users and victims' personal characteristics are found in the media reporting of crashes. More severe crashes are reported in the media more easily than less severe crashes. Significant fluctuations in media reporting probability through time are found in terms of the year and month in which the crash took place. Crashes during week days are generally less reported in the news. The geographical area (province) in which the crash takes place also has a significant impact on the probability of being reported in the news. Crashes on motorways are significantly more represented in the news. Regarding the age of the involved victims, a clear trend of higher media reporting rates of crashes involving young victims or young fatalities is observed. Crashes involving female fatalities are also more frequently reported in the news. Furthermore, crashes involving a bus have a significantly higher probability of being reported in the news, while crashes involving a motorcycle have a significantly lower probability. Some models also indicate a lower reporting rate of crashes involving a moped, and a higher reporting rate of crashes involving heavy goods vehicles. These biases in media reporting can create skewed perceptions in the general public about the prevalence of traffic crashes and eventually may influence people's behaviour.

  4. "Crashing the gates" - selection criteria for television news reporting of traffic crashes.

    PubMed

    De Ceunynck, Tim; De Smedt, Julie; Daniels, Stijn; Wouters, Ruud; Baets, Michèle

    2015-07-01

    This study investigates which crash characteristics influence the probability that the crash is reported in the television news. To this purpose, all news items from the period 2006-2012 about traffic crashes from the prime time news of two Belgian television channels are linked to the official injury crash database. Logistic regression models are built for the database of all injury crashes and for the subset of fatal crashes to identify crash characteristics that correlate with a lower or higher probability of being reported in the news. A number of significant biases in terms of crash severity, time, place, types of involved road users and victims' personal characteristics are found in the media reporting of crashes. More severe crashes are reported in the media more easily than less severe crashes. Significant fluctuations in media reporting probability through time are found in terms of the year and month in which the crash took place. Crashes during week days are generally less reported in the news. The geographical area (province) in which the crash takes place also has a significant impact on the probability of being reported in the news. Crashes on motorways are significantly more represented in the news. Regarding the age of the involved victims, a clear trend of higher media reporting rates of crashes involving young victims or young fatalities is observed. Crashes involving female fatalities are also more frequently reported in the news. Furthermore, crashes involving a bus have a significantly higher probability of being reported in the news, while crashes involving a motorcycle have a significantly lower probability. Some models also indicate a lower reporting rate of crashes involving a moped, and a higher reporting rate of crashes involving heavy goods vehicles. These biases in media reporting can create skewed perceptions in the general public about the prevalence of traffic crashes and eventually may influence people's behaviour. PMID:25909390

  5. A Fully Automated and Robust Method to Incorporate Stamping Data in Crash, NVH and Durability Analysis

    NASA Astrophysics Data System (ADS)

    Palaniswamy, Hariharasudhan; Kanthadai, Narayan; Roy, Subir; Beauchesne, Erwan

    2011-08-01

    Crash, NVH (Noise, Vibration, Harshness), and durability analysis are commonly deployed in structural CAE analysis for mechanical design of components especially in the automotive industry. Components manufactured by stamping constitute a major portion of the automotive structure. In CAE analysis they are modeled at a nominal state with uniform thickness and no residual stresses and strains. However, in reality the stamped components have non-uniformly distributed thickness and residual stresses and strains resulting from stamping. It is essential to consider the stamping information in CAE analysis to accurately model the behavior of the sheet metal structures under different loading conditions. Especially with the current emphasis on weight reduction by replacing conventional steels with aluminum and advanced high strength steels it is imperative to avoid over design. Considering this growing need in industry, a highly automated and robust method has been integrated within Altair Hyperworks® to initialize sheet metal components in CAE models with stamping data. This paper demonstrates this new feature and the influence of stamping data for a full car frontal crash analysis.

  6. Characteristics of Older Motorcyclist Crashes

    PubMed Central

    Stutts, Jane; Foss, Robert; Svoboda, Colleen

    2004-01-01

    In the U.S. as well as other countries, the number of motorcyclists killed in traffic crashes has risen sharply over the past five years, due in part to the increased popularity of motorcycling among older riders. This paper examines trends in motorcyclist casualties and vehicle registrations from 1990–2002, based on national and state (North Carolina) motor vehicle crash and vehicle registration data. The data show similar patterns of increased fatalities that parallel a growth in motorcycle registrations. Whereas the number of motorcyclists ages 16–24 declined over the 13–year study period, the number of riders ages 35 and older increased. Three years of recent (2000–2002) NC data are examined to identify salient characteristics of the crashes of these older riders. Results are discussed with respect to approaches for mitigating the increase in motorcyclist deaths and injuries. PMID:15319126

  7. Crash protectiveness to occupant injury and vehicle damage: An investigation on major car brands.

    PubMed

    Huang, Helai; Li, Chunyang; Zeng, Qiang

    2016-01-01

    This study sets out to investigate vehicles' crash protectiveness on occupant injury and vehicle damage, which can be deemed as an extension of the traditional crash worthiness. A Bayesian bivariate hierarchical ordered logistic (BVHOL) model is developed to estimate the occupant protectiveness (OP) and vehicle protectiveness (VP) of 23 major car brands in Florida, with considering vehicles' crash aggressivity and controlling external factors. The proposed model not only takes over the strength of the existing hierarchical ordered logistic (HOL) model, i.e. specifying the order characteristics of crash outcomes and cross-crash heterogeneities, but also accounts for the correlation between the two crash responses, driver injury and vehicle damage. A total of 7335 two-vehicle-crash records with 14,670 cars involved in Florida are used for the investigation. From the estimation results, it's found that most of the luxury cars such as Cadillac, Volvo and Lexus possess excellent OP and VP while some brands such as KIA and Saturn perform very badly in both aspects. The ranks of the estimated safety performance indices are even compared to the counterparts in Huang et al. study [Huang, H., Hu, S., Abdel-Aty, M., 2014. Indexing crash worthiness and crash aggressivity by major car brands. Safety Science 62, 339-347]. The results show that the rank of occupant protectiveness index (OPI) is relatively coherent with that of crash worthiness index, but the ranks of crash aggressivity index in both studies is more different from each other. Meanwhile, a great discrepancy between the OPI rank and that of vehicle protectiveness index is found. What's more, the results of control variables and hyper-parameters estimation as well as comparison to HOL models with separate or identical threshold errors, demonstrate the validity and advancement of the proposed model and the robustness of the estimated OP and VP.

  8. Crash protectiveness to occupant injury and vehicle damage: An investigation on major car brands.

    PubMed

    Huang, Helai; Li, Chunyang; Zeng, Qiang

    2016-01-01

    This study sets out to investigate vehicles' crash protectiveness on occupant injury and vehicle damage, which can be deemed as an extension of the traditional crash worthiness. A Bayesian bivariate hierarchical ordered logistic (BVHOL) model is developed to estimate the occupant protectiveness (OP) and vehicle protectiveness (VP) of 23 major car brands in Florida, with considering vehicles' crash aggressivity and controlling external factors. The proposed model not only takes over the strength of the existing hierarchical ordered logistic (HOL) model, i.e. specifying the order characteristics of crash outcomes and cross-crash heterogeneities, but also accounts for the correlation between the two crash responses, driver injury and vehicle damage. A total of 7335 two-vehicle-crash records with 14,670 cars involved in Florida are used for the investigation. From the estimation results, it's found that most of the luxury cars such as Cadillac, Volvo and Lexus possess excellent OP and VP while some brands such as KIA and Saturn perform very badly in both aspects. The ranks of the estimated safety performance indices are even compared to the counterparts in Huang et al. study [Huang, H., Hu, S., Abdel-Aty, M., 2014. Indexing crash worthiness and crash aggressivity by major car brands. Safety Science 62, 339-347]. The results show that the rank of occupant protectiveness index (OPI) is relatively coherent with that of crash worthiness index, but the ranks of crash aggressivity index in both studies is more different from each other. Meanwhile, a great discrepancy between the OPI rank and that of vehicle protectiveness index is found. What's more, the results of control variables and hyper-parameters estimation as well as comparison to HOL models with separate or identical threshold errors, demonstrate the validity and advancement of the proposed model and the robustness of the estimated OP and VP. PMID:26551733

  9. PTSD After Severe Vehicular Crashes

    PubMed Central

    Ryb, Gabriel E.; Dischinger, Patricia C.; Read, Kathleen M.; Kufera, Joseph A.

    2009-01-01

    Purpose: To describe predictors of PTSD after motor vehicle crashes (MVC). Methods: MVC patients were interviewed during their hospitalization and at 6 and 12 months post-injury. Interviews included information about behavioral factors, circumstances around the crash, recovery and PTSD screening. PTSD was defined as the development of 3 or more of 7 PTSD symptoms. Association of risk factors with PTSD development at 6 and 12 months was analyzed using contingency tables. Multiple regression models were built for the prediction of PTSD. Results: 367 and 317 patients completed the 6 and 12 month interviews respecively. PTSD developed in 27.5 % (n=101) and 24.3 % (n=77) of the population at 6 and 12 months repectively. PTSD occurred more frequently among females, those with a previous history of depression, violent injury, or other traumatic events, and those whose crashes involved a fatality. Those who were culpable for the crash, age<30, and sustained brain injuries were less likely to develop PTSD at 6 months. Occupant position, education, marital status, alcohol problems, injury severity, heart rate, and blood alcohol + status did not show any significant association with PTSD. In the multiple logistic regression, female gender, history of depression, culpabilty, prior violent injury, and a fatality in the crash were associated with PTSD at 6 months. Only prior violent injury, and a death in same crash were predictors at one year. Conclusion: PTSD occurs frequently after MVCs. Female gender, prior violent injury, death of another occupant and history of depression are associated with PTSD development. PMID:20184843

  10. Digital-Difference Processing For Collision Avoidance.

    NASA Technical Reports Server (NTRS)

    Shores, Paul; Lichtenberg, Chris; Kobayashi, Herbert S.; Cunningham, Allen R.

    1988-01-01

    Digital system for automotive crash avoidance measures and displays difference in frequency between two sinusoidal input signals of slightly different frequencies. Designed for use with Doppler radars. Characterized as digital mixer coupled to frequency counter measuring difference frequency in mixer output. Technique determines target path mathematically. Used for tracking cars, missiles, bullets, baseballs, and other fast-moving objects.

  11. Modeling crash spatial heterogeneity: random parameter versus geographically weighting.

    PubMed

    Xu, Pengpeng; Huang, Helai

    2015-02-01

    The widely adopted techniques for regional crash modeling include the negative binomial model (NB) and Bayesian negative binomial model with conditional autoregressive prior (CAR). The outputs from both models consist of a set of fixed global parameter estimates. However, the impacts of predicting variables on crash counts might not be stationary over space. This study intended to quantitatively investigate this spatial heterogeneity in regional safety modeling using two advanced approaches, i.e., random parameter negative binomial model (RPNB) and semi-parametric geographically weighted Poisson regression model (S-GWPR). Based on a 3-year data set from the county of Hillsborough, Florida, results revealed that (1) both RPNB and S-GWPR successfully capture the spatially varying relationship, but the two methods yield notably different sets of results; (2) the S-GWPR performs best with the highest value of Rd(2) as well as the lowest mean absolute deviance and Akaike information criterion measures. Whereas the RPNB is comparable to the CAR, in some cases, it provides less accurate predictions; (3) a moderately significant spatial correlation is found in the residuals of RPNB and NB, implying the inadequacy in accounting for the spatial correlation existed across adjacent zones. As crash data are typically collected with reference to location dimension, it is desirable to firstly make use of the geographical component to explore explicitly spatial aspects of the crash data (i.e., the spatial heterogeneity, or the spatially structured varying relationships), then is the unobserved heterogeneity by non-spatial or fuzzy techniques. The S-GWPR is proven to be more appropriate for regional crash modeling as the method outperforms the global models in capturing the spatial heterogeneity occurring in the relationship that is model, and compared with the non-spatial model, it is capable of accounting for the spatial correlation in crash data.

  12. Modeling crash spatial heterogeneity: random parameter versus geographically weighting.

    PubMed

    Xu, Pengpeng; Huang, Helai

    2015-02-01

    The widely adopted techniques for regional crash modeling include the negative binomial model (NB) and Bayesian negative binomial model with conditional autoregressive prior (CAR). The outputs from both models consist of a set of fixed global parameter estimates. However, the impacts of predicting variables on crash counts might not be stationary over space. This study intended to quantitatively investigate this spatial heterogeneity in regional safety modeling using two advanced approaches, i.e., random parameter negative binomial model (RPNB) and semi-parametric geographically weighted Poisson regression model (S-GWPR). Based on a 3-year data set from the county of Hillsborough, Florida, results revealed that (1) both RPNB and S-GWPR successfully capture the spatially varying relationship, but the two methods yield notably different sets of results; (2) the S-GWPR performs best with the highest value of Rd(2) as well as the lowest mean absolute deviance and Akaike information criterion measures. Whereas the RPNB is comparable to the CAR, in some cases, it provides less accurate predictions; (3) a moderately significant spatial correlation is found in the residuals of RPNB and NB, implying the inadequacy in accounting for the spatial correlation existed across adjacent zones. As crash data are typically collected with reference to location dimension, it is desirable to firstly make use of the geographical component to explore explicitly spatial aspects of the crash data (i.e., the spatial heterogeneity, or the spatially structured varying relationships), then is the unobserved heterogeneity by non-spatial or fuzzy techniques. The S-GWPR is proven to be more appropriate for regional crash modeling as the method outperforms the global models in capturing the spatial heterogeneity occurring in the relationship that is model, and compared with the non-spatial model, it is capable of accounting for the spatial correlation in crash data. PMID:25460087

  13. Can-Filled Crash Barrier

    NASA Technical Reports Server (NTRS)

    Wilson, A. H.

    1983-01-01

    Crash barrier composed largely of used aluminum beverage cans protects occupants of cars in collisions with poles or trees. Lightweight, can-filled barrier very effective in softening impact of an automobile in head-on and off-angle collisions. Preliminary results indicate barrier is effective in collisions up to 40 mi/h (64 km/h).

  14. The Sound of Cymbals Crashing.

    ERIC Educational Resources Information Center

    Levy, Sal

    1991-01-01

    Presents an outdoor experiment to measure the speed of sound as a classroom experience to begin the teaching year. Measures the delay time from seeing and hearing crashing cymbals across a field to calculate the speed. Exposes students to experimental uncertainties and limits of uncertainty in measurement. (MDH)

  15. Impact of pavement conditions on crash severity.

    PubMed

    Li, Yingfeng; Liu, Chunxiao; Ding, Liang

    2013-10-01

    Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses.

  16. Investigations of Crashes Involving Pregnant Occupants

    PubMed Central

    Klinich, Kathleen DeSantis; Schneider, Lawrence W.; Moore, Jamie L.; Pearlman, Mark D.

    2000-01-01

    Case reports of 16 crashes involving pregnant occupants are presented that illustrate the main conclusions of a crash-investigation program that includes 42 crashes investigated to date. Some unusual cases that are exceptions to the overall trends are also described. The study indicates a strong association between adverse fetal outcome and both crash severity and maternal injury. Proper restraint use, with and without airbag deployment, generally leads to acceptable fetal outcomes in lower severity crashes, while it does not affect fetal outcome in high-severity crashes. Compared to properly restrained pregnant occupants, improperly restrained occupants have a higher risk of adverse fetal outcome in lower severity crashes, which comprise the majority of all motor-vehicle collisions. PMID:11558095

  17. Naturalistic Assessment of Novice Teenage Crash Experience

    PubMed Central

    Lee, Suzanne E.; Simons-Morton, Bruce G.; Klauer, Sheila E.; Ouimet, Marie Claude; Dingus, Thomas A.

    2011-01-01

    Background Crash risk is highest during the first months after licensure. Current knowledge about teenagers’ driving exposure and the factors increasing their crash risk is based on self-reported data and crash database analyses. While these research tools are useful, new developments in naturalistic technologies have allowed researchers to examine newly-licensed teenagers’ exposure and crash risk factors in greater detail. The Naturalistic Teenage Driving Study (NTDS) described in this paper is the first study to follow a group of newly-licensed teenagers continuously for 18 months after licensure. The goals of this paper are to compare the crash and near-crash experience of drivers in the NTDS to national trends, to describe the methods and lessons learned in the NTDS, and to provide initial data on driving exposure for these drivers. Methods A data acquisition system was installed in the vehicles of 42 newly-licensed teenage drivers 16 years of age during their first 18 months of independent driving. It consisted of cameras, sensors (accelerometers, GPS, yaw, front radar, lane position, and various sensors obtained via the vehicle network), and a computer with removable hard drive. Data on the driving of participating parents was also collected when they drove the instrumented vehicle. Findings The primary findings after 18 months included the following: (1) crash and near-crash rates among teenage participants were significantly higher during the first six months of the study than the final 12 months, mirroring the national trends; (2) crash and near-crash rates were significantly higher for teenage than adult (parent) participants, also reflecting national trends; (3) teenaged driving exposure averaged between 507-710 kilometers (315-441 miles) per month over the study period, but varied substantially between participants with standard errors representing 8-14 percent of the mean; and (4) crash and near-crash types were very similar for male and female

  18. Modelling the hierarchical structure of road crash data--application to severity analysis.

    PubMed

    Lenguerrand, E; Martin, J L; Laumon, B

    2006-01-01

    Road crashes have an unquestionably hierarchical crash-car-occupant structure. Multilevel models are used with correlated data, but their application to crash data can be difficult. The number of sub-clusters per cluster is small, with less than two cars per crash and less than two occupants per car, whereas the number of clusters can be high, with several hundred/thousand crashes. Application of the Monte-Carlo method on observed and simulated French road crash data between 1996 and 2000 allows comparing estimations produced by multilevel logistic models (MLM), Generalized Estimating Equation models (GEE) and logistic models (LM). On the strength of a bias study, MLM is the most efficient model while both GEE and LM underestimate parameters and confidence intervals. MLM is used as a marginal model and not as a random-effect model, i.e. only fixed effects are taken into account. Random effects allow adjusting risks on the hierarchical structure, conferring an interpretative advantage to MLM over GEE. Nevertheless, great care is needed for data coding and quite a high number of crashes are necessary in order to avoid problems and errors with estimates and estimate processes. On balance, MLM must be used when the number of vehicles per crash or the number of occupants per vehicle is high, when the LM results are questionable because they are not in line with the literature or finally when the p-values associated to risk measures are close to 5%. In other cases, LM remains a practical analytical tool for modelling crash data. PMID:16126153

  19. Re-visiting crash-speed relationships: A new perspective in crash modelling.

    PubMed

    Imprialou, Maria-Ioanna M; Quddus, Mohammed; Pitfield, David E; Lord, Dominique

    2016-01-01

    Although speed is considered to be one of the main crash contributory factors, research findings are inconsistent. Independent of the robustness of their statistical approaches, crash frequency models typically employ crash data that are aggregated using spatial criteria (e.g., crash counts by link termed as a link-based approach). In this approach, the variability in crashes between links is explained by highly aggregated average measures that may be inappropriate, especially for time-varying variables such as speed and volume. This paper re-examines crash-speed relationships by creating a new crash data aggregation approach that enables improved representation of the road conditions just before crash occurrences. Crashes are aggregated according to the similarity of their pre-crash traffic and geometric conditions, forming an alternative crash count dataset termed as a condition-based approach. Crash-speed relationships are separately developed and compared for both approaches by employing the annual crashes that occurred on the Strategic Road Network of England in 2012. The datasets are modelled by injury severity using multivariate Poisson lognormal regression, with multivariate spatial effects for the link-based model, using a full Bayesian inference approach. The results of the condition-based approach show that high speeds trigger crash frequency. The outcome of the link-based model is the opposite; suggesting that the speed-crash relationship is negative regardless of crash severity. The differences between the results imply that data aggregation is a crucial, yet so far overlooked, methodological element of crash data analyses that may have direct impact on the modelling outcomes.

  20. Crash energy absorption of two-segment crash box with holes under frontal load

    NASA Astrophysics Data System (ADS)

    Choiron, Moch. Agus; Sudjito, Hidayati, Nafisah Arina

    2016-03-01

    Crash box is one of the passive safety components which designed as an impact energy absorber during collision. Crash box designs have been developed in order to obtain the optimum crashworthiness performance. Circular cross section was first investigated with one segment design, it rather influenced by its length which is being sensitive to the buckling occurrence. In this study, the two-segment crash box design with additional holes is investigated and deformation behavior and crash energy absorption are observed. The crash box modelling is performed by finite element analysis. The crash test components were impactor, crash box, and fixed rigid base. Impactor and the fixed base material are modelled as a rigid, and crash box material as bilinear isotropic hardening. Crash box length of 100 mm and frontal crash velocity of 16 km/jam are selected. Crash box material of Aluminum Alloy is used. Based on simulation results, it can be shown that holes configuration with 2 holes and ¾ length locations have the largest crash energy absorption. This condition associated with deformation pattern, this crash box model produces axisymmetric mode than other models.

  1. A multivariate Poisson-lognormal regression model for prediction of crash counts by severity, using Bayesian methods.

    PubMed

    Ma, Jianming; Kockelman, Kara M; Damien, Paul

    2008-05-01

    Numerous efforts have been devoted to investigating crash occurrence as related to roadway design features, environmental factors and traffic conditions. However, most of the research has relied on univariate count models; that is, traffic crash counts at different levels of severity are estimated separately, which may neglect shared information in unobserved error terms, reduce efficiency in parameter estimates, and lead to potential biases in sample databases. This paper offers a multivariate Poisson-lognormal (MVPLN) specification that simultaneously models crash counts by injury severity. The MVPLN specification allows for a more general correlation structure as well as overdispersion. This approach addresses several questions that are difficult to answer when estimating crash counts separately. Thanks to recent advances in crash modeling and Bayesian statistics, parameter estimation is done within the Bayesian paradigm, using a Gibbs Sampler and the Metropolis-Hastings (M-H) algorithms for crashes on Washington State rural two-lane highways. Estimation results from the MVPLN approach show statistically significant correlations between crash counts at different levels of injury severity. The non-zero diagonal elements suggest overdispersion in crash counts at all levels of severity. The results lend themselves to several recommendations for highway safety treatments and design policies. For example, wide lanes and shoulders are key for reducing crash frequencies, as are longer vertical curves. PMID:18460364

  2. Identification of a crash model

    NASA Astrophysics Data System (ADS)

    Mizzi, J. P.; Jezequel, L.

    1992-11-01

    Our knowledge of the behaviour of passenger cars and road safety systems during a crash trial is based on experimental studies. A survey was carried out on the modelling of the front compartment of a passenger car: the model will make it possible to enlarge the conclusions drawn from a test by extending the results to different situations. We have designed a mathematical spring-masses model which simulates the behaviour of a passenger car during various frontal crash configurations. However, the main difficulty is to know perfectly the laws of behaviour of the springs. That is why an identification methodology was envisaged from the configuration of the experimental results. To know the vehicle's real behaviour during a crash trial, it is necessary to have experimental devices which make it possible to rebuild the space kinematics of the components. We thus designed, in each case, suitable acquisition and processing software. Different non-parametric and parametric identification methods were then tested on simple and then complex models. The results have permitted us to determine which is the best adapted to solve our problem.

  3. Case series analysis of hindfoot injuries sustained by drivers in frontal motor vehicle crashes.

    PubMed

    Ye, Xin; Funk, James; Forbes, Aaron; Hurwitz, Shepard; Shaw, Greg; Crandall, Jeff; Freeth, Rob; Michetti, Chris; Rudd, Rodney; Scarboro, Mark

    2015-09-01

    Improvements to vehicle frontal crashworthiness have led to reductions in toe pan and instrument panel intrusions as well as leg, foot, and ankle loadings in standardized crash tests. Current field data, however, suggests the proportion of foot and ankle injuries sustained by drivers in frontal crashes has not decreased over the past two decades. To explain the inconsistency between crash tests results and real world lower limb injury prevalence, this study investigated the injury causation scenario for the specific hind-foot injury patterns observed in frontal vehicle crashes. Thirty-four cases with leg, foot, and ankle injuries were selected from the Crash Injury Research and Engineering Network (CIREN) database. Talus fractures were present in 20 cases, representing the most frequent hind-foot skeletal injuries observed among the reviewed cases. While axial compression was the predominant loading mechanism causing 18 injuries, 11 injured ankles involved inversion or eversion motion, and 5 involved dorsiflexion as the injury mechanism. Injured ankles of drivers were more biased towards the right aspect with foot pedals contributing to injuries in 13 of the 34 cases. Combined, the results suggest that despite recent advancement of vehicle performance in crash tests, efforts to reduce axial forces sustained in lower extremity should be prioritized. The analysis of injury mechanisms in this study could aid in crash reconstructions and the development of safety systems for vehicles. PMID:26183693

  4. On the significance of omitted variables in intersection crash modeling.

    PubMed

    Mitra, Sudeshna; Washington, Simon

    2012-11-01

    Advances in safety research--trying to improve the collective understanding of motor vehicle crash causes and contributing factors--rest upon the pursuit of numerous lines of research inquiry. The research community has focused considerable attention on analytical methods development (negative binomial models, simultaneous equations, etc.), on better experimental designs (before-after studies, comparison sites, etc.), on improving exposure measures, and on model specification improvements (additive terms, non-linear relations, etc.). One might logically seek to know which lines of inquiry might provide the most significant improvements in understanding crash causation and/or prediction. It is the contention of this paper that the exclusion of important variables (causal or surrogate measures of causal variables) cause omitted variable bias in model estimation and is an important and neglected line of inquiry in safety research. In particular, spatially related variables are often difficult to collect and omitted from crash models--but offer significant opportunities to better understand contributing factors and/or causes of crashes. This study examines the role of important variables (other than Average Annual Daily Traffic (AADT)) that are generally omitted from intersection crash prediction models. In addition to the geometric and traffic regulatory information of intersection, the proposed model includes many spatial factors such as local influences of weather, sun glare, proximity to drinking establishments, and proximity to schools--representing a mix of potential environmental and human factors that are theoretically important, but rarely used. Results suggest that these variables in addition to AADT have significant explanatory power, and their exclusion leads to omitted variable bias. Provided is evidence that variable exclusion overstates the effect of minor road AADT by as much as 40% and major road AADT by 14%.

  5. Multifractal analysis of stock exchange crashes

    NASA Astrophysics Data System (ADS)

    Siokis, Fotios M.

    2013-03-01

    We analyze the complexity of rare events of the DJIA Index. We reveal that the returns of the time series exhibit strong multifractal properties meaning that temporal correlations play a substantial role. The effect of major stock market crashes can be best illustrated by the comparison of the multifractal spectra of the time series before and after the crash. Aftershock periods compared to foreshock periods exhibit richer and more complex dynamics. Compared to an average crash, calculated by taking into account the larger 5 crashes of the DJIA Index, the 1929 event exhibits significantly more increase in multifractality than the 1987 crisis.

  6. Requirements of a system to reduce car-to-vulnerable road user crashes in urban intersections.

    PubMed

    Habibovic, Azra; Davidsson, Johan

    2011-07-01

    Intersection crashes between cars and vulnerable road users (VRUs), such as pedestrians and bicyclists, often result in injuries and fatalities. Advanced driver assistance systems (ADASs) can prevent, or mitigate, these crashes. To derive functional requirements for such systems, an understanding of the underlying contributing factors and the context in which the crashes occur is essential. The aim of this study is to use microscopic and macroscopic crash data to explore the potential of information and warning providing ADASs, and then to derive functional sensor, collision detection, and human-machine interface (HMI) requirements. The microscopic data were obtained from the European project SafetyNet. Causation charts describing contributing factors for 60 car-to-VRU crashes had been compiled and were then also aggregated using the SafetyNet Accident Causation System (SNACS). The macroscopic data were obtained from the Swedish national crash database, STRADA. A total of 9702 crashes were analyzed. The results show that the most frequent contributing factor to the crashes was the drivers' failure to observe VRUs due to reduced visibility, reduced awareness, and/or insufficient comprehension. An ADAS should therefore help drivers to observe the VRUs in time and to enhance their ability to interpret the development of events in the near future. The system should include a combination of imminent and cautionary collision warnings, with additional support in the form of information about intersection geometry and traffic regulations. The warnings should be deployed via an in-vehicle HMI and according to the likelihood of crash risk. The system should be able to operate under a variety of weather and light conditions. It should have the capacity to support drivers when their view is obstructed by physical objects. To address problems that vehicle-based sensors may face in this regard, the use of cooperative systems is recommended.

  7. Requirements of a system to reduce car-to-vulnerable road user crashes in urban intersections.

    PubMed

    Habibovic, Azra; Davidsson, Johan

    2011-07-01

    Intersection crashes between cars and vulnerable road users (VRUs), such as pedestrians and bicyclists, often result in injuries and fatalities. Advanced driver assistance systems (ADASs) can prevent, or mitigate, these crashes. To derive functional requirements for such systems, an understanding of the underlying contributing factors and the context in which the crashes occur is essential. The aim of this study is to use microscopic and macroscopic crash data to explore the potential of information and warning providing ADASs, and then to derive functional sensor, collision detection, and human-machine interface (HMI) requirements. The microscopic data were obtained from the European project SafetyNet. Causation charts describing contributing factors for 60 car-to-VRU crashes had been compiled and were then also aggregated using the SafetyNet Accident Causation System (SNACS). The macroscopic data were obtained from the Swedish national crash database, STRADA. A total of 9702 crashes were analyzed. The results show that the most frequent contributing factor to the crashes was the drivers' failure to observe VRUs due to reduced visibility, reduced awareness, and/or insufficient comprehension. An ADAS should therefore help drivers to observe the VRUs in time and to enhance their ability to interpret the development of events in the near future. The system should include a combination of imminent and cautionary collision warnings, with additional support in the form of information about intersection geometry and traffic regulations. The warnings should be deployed via an in-vehicle HMI and according to the likelihood of crash risk. The system should be able to operate under a variety of weather and light conditions. It should have the capacity to support drivers when their view is obstructed by physical objects. To address problems that vehicle-based sensors may face in this regard, the use of cooperative systems is recommended. PMID:21545892

  8. A multivariate spatial crash frequency model for identifying sites with promise based on crash types.

    PubMed

    Jonathan, Aguero-Valverde; Wu, Kun-Feng Ken; Donnell, Eric T

    2016-02-01

    Many studies have proposed the use of a systemic approach to identify sites with promise (SWiPs). Proponents of the systemic approach to road safety management suggest that it is more effective in reducing crash frequency than the traditional hot spot approach. The systemic approach aims to identify SWiPs by crash type(s) and, therefore, effectively connects crashes to their corresponding countermeasures. Nevertheless, a major challenge to implementing this approach is the low precision of crash frequency models, which results from the systemic approach considering subsets (crash types) of total crashes leading to higher variability in modeling outcomes. This study responds to the need for more precise statistical output and proposes a multivariate spatial model for simultaneously modeling crash frequencies for different crash types. The multivariate spatial model not only induces a multivariate correlation structure between crash types at the same site, but also spatial correlation among adjacent sites to enhance model precision. This study utilized crash, traffic, and roadway inventory data on rural two-lane highways in Pennsylvania to construct and test the multivariate spatial model. Four models with and without the multivariate and spatial correlations were tested and compared. The results show that the model that considers both multivariate and spatial correlation has the best fit. Moreover, it was found that the multivariate correlation plays a stronger role than the spatial correlation when modeling crash frequencies in terms of different crash types.

  9. Relative risk of death from ejection by crash type and crash mode.

    PubMed

    Esterlitz, J R

    1989-10-01

    In virtually all circumstances, the chance of survival in a crash is much greater if the occupant is not ejected from the vehicle. Several estimates of the increased risk of death as a result of ejection (ranging from 2.5 to 25) have been made, but none were specific to the crash mode and most did not control for crash severity. The current study examined the relative risk of fatality due to ejection, by crash type and crash mode, using the Fatal Accident Reporting System data from the years 1982 through 1986. Crash type was defined as either single vehicle or multivehicle and crash mode included rollover, nonrollover, and/or direction of impact. Crash severity was controlled for using a paired comparison method of analysis. Both crash type and crash mode were found to have substantial effects on the relative risk of death due to ejection. In addition, risk differences across seating position exist. Depending on crash mode or type, the risks ranged from about 1.5 to 8. Single-vehicle rollover crashes have the highest increased risk of death due to ejection: about eightfold for the driver and sevenfold for the right front passenger. PMID:2619855

  10. CDC Vital Signs: Motor Vehicle Crash Injuries: Costly but Preventable

    MedlinePlus

    ... Press Kit Read the MMWR Science Clips Motor Vehicle Crash Injuries Costly but Preventable Language: English Español ( ... and how to prevent future crashes. Problem Motor vehicle crashes are a leading cause of injury in ...

  11. Application of Probability Methods to Assess Crash Modeling Uncertainty

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Stockwell, Alan E.; Hardy, Robin C.

    2003-01-01

    Full-scale aircraft crash simulations performed with nonlinear, transient dynamic, finite element codes can incorporate structural complexities such as: geometrically accurate models; human occupant models; and advanced material models to include nonlinear stress-strain behaviors, and material failure. Validation of these crash simulations is difficult due to a lack of sufficient information to adequately determine the uncertainty in the experimental data and the appropriateness of modeling assumptions. This paper evaluates probabilistic approaches to quantify the effects of finite element modeling assumptions on the predicted responses. The vertical drop test of a Fokker F28 fuselage section will be the focus of this paper. The results of a probabilistic analysis using finite element simulations will be compared with experimental data.

  12. Application of Probability Methods to Assess Crash Modeling Uncertainty

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Stockwell, Alan E.; Hardy, Robin C.

    2007-01-01

    Full-scale aircraft crash simulations performed with nonlinear, transient dynamic, finite element codes can incorporate structural complexities such as: geometrically accurate models; human occupant models; and advanced material models to include nonlinear stress-strain behaviors, and material failure. Validation of these crash simulations is difficult due to a lack of sufficient information to adequately determine the uncertainty in the experimental data and the appropriateness of modeling assumptions. This paper evaluates probabilistic approaches to quantify the effects of finite element modeling assumptions on the predicted responses. The vertical drop test of a Fokker F28 fuselage section will be the focus of this paper. The results of a probabilistic analysis using finite element simulations will be compared with experimental data.

  13. Comparison of teen and adult driver crash scenarios in a nationally representative sample of serious crashes.

    PubMed

    McDonald, Catherine C; Curry, Allison E; Kandadai, Venk; Sommers, Marilyn S; Winston, Flaura K

    2014-11-01

    Motor vehicle crashes are the leading cause of death and acquired disability during the first four decades of life. While teen drivers have the highest crash risk, few studies examine the similarities and differences in teen and adult driver crashes. We aimed to: (1) identify and compare the most frequent crash scenarios-integrated information on a vehicle's movement prior to crash, immediate pre-crash event, and crash configuration-for teen and adult drivers involved in serious crashes, and (2) for the most frequent scenarios, explore whether the distribution of driver critical errors differed for teens and adult drivers. We analyzed data from the National Motor Vehicle Crash Causation Survey, a nationally representative study of serious crashes conducted by the U.S. National Highway Traffic Safety Administration from 2005 to 2007. Our sample included 642 16- to 19-year-old and 1167 35- to 54-year-old crash-involved drivers (weighted n=296,482 and 439,356, respectively) who made a critical error that led to their crash's critical pre-crash event (i.e., event that made the crash inevitable). We estimated prevalence ratios (PR) and 95% confidence intervals (CI) to compare the relative frequency of crash scenarios and driver critical errors. The top five crash scenarios among teen drivers, accounting for 37.3% of their crashes, included: (1) going straight, other vehicle stopped, rear end; (2) stopped in traffic lane, turning left at intersection, turn into path of other vehicle; (3) negotiating curve, off right edge of road, right roadside departure; (4) going straight, off right edge of road, right roadside departure; and (5) stopped in lane, turning left at intersection, turn across path of other vehicle. The top five crash scenarios among adult drivers, accounting for 33.9% of their crashes, included the same scenarios as the teen drivers with the exception of scenario (3) and the addition of going straight, crossing over an intersection, and continuing on a

  14. Avoiding Ticks

    MedlinePlus

    ... Avoiding ticks On people On pets In the yard Removing a tick Symptoms of tickborne illness Geographic ... ticks on your pets Preventing ticks in the yard File Formats Help: How do I view different ...

  15. Investigation of dynamics of ELM crashes and their mitigation techniques

    SciTech Connect

    Pankin, Alexei Y.

    2015-08-14

    The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations

  16. Post-crash fuel dispersal

    SciTech Connect

    Tieszen, S.R.

    1997-03-01

    This paper is a brief overview of work over the last several decades in understanding what occurs to jet fuel stored in aircraft fuel tanks on impact with the ground. Fuel dispersal is discussed in terms of the overall crash dynamics process and impact regimes are identified. In a generic sense, the types of flow regimes which can occur are identified and general descriptions of the processes are given. Examples of engineering level tools, both computational and experimental, which have applicability to analyzing the complex environments are presented. Finally, risk based decision is discussed as a quick means of identifying requirements for development of preventative or mitigation strategies, such as further work on the development of an anti-misting agent.

  17. Forensic aspects of the highway crash.

    PubMed

    Gikas, P W

    1983-01-01

    It can be stated that patterns of injury in highway crashes can often be related to specific design and damage features of the vehicle. The restraint systems designed to attenuate injury may also, under severe crash circumstances, produce trauma. Problems may arise as to identification of vehicular drivers. It behooves the pathologist concerned with the necropsy of crash victims and the physician responsible for treating crash victims to become familiar with the pathogenesis of injuries. Such knowledge can be utilized in the recommendation for improvement of vehicles to render them more crashworthy. Awareness of the various mechanisms of injury in vehicle crashes also enhances the diagnostic skill of the initial treating physician when he or she is confronted with a crash victim in the emergency department. Ideally, when the victim arrives at the hospital, the emergency room physician should be supplied with the details of the crash including the type of vehicle, position within the vehicle, use or nonuse of restraint systems, and the direction of the impact. When a fatality results from a car crash, ideally the autopsy pathologist should inspect the vehicle or at least view pictures of the exterior and interior of the vehicle to help establish the pathogenesis of injury in a specific collision. Unfortunately, because of time constraints, this ideal is not always achieved. Because of the considerable volume of civil and criminal litigation resulting from highway crashes, there is a need for competent medical expertise to help both the plaintiff and the defendent. The pathologist involved in forensic work and the treating physician play a particularly important role in the judicial arena.

  18. 49 CFR 238.403 - Crash energy management.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  19. 49 CFR 238.403 - Crash energy management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  20. 49 CFR 238.403 - Crash energy management.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  1. 49 CFR 238.403 - Crash energy management.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  2. 49 CFR 238.403 - Crash energy management.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  3. Factors Contributing to Crashes among Young Drivers.

    PubMed

    Bates, Lyndel J; Davey, Jeremy; Watson, Barry; King, Mark J; Armstrong, Kerry

    2014-08-01

    Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures.

  4. Deployable System for Crash-Load Attenuation

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris; Jackson, Karen E.

    2007-01-01

    An externally deployable honeycomb structure is investigated with respect to crash energy management for light aircraft. The new concept utilizes an expandable honeycomb-like structure to absorb impact energy by crushing. Distinguished by flexible hinges between cell wall junctions that enable effortless deployment, the new energy absorber offers most of the desirable features of an external airbag system without the limitations of poor shear stability, system complexity, and timing sensitivity. Like conventional honeycomb, once expanded, the energy absorber is transformed into a crush efficient and stable cellular structure. Other advantages, afforded by the flexible hinge feature, include a variety of deployment options such as linear, radial, and/or hybrid deployment methods. Radial deployment is utilized when omnidirectional cushioning is required. Linear deployment offers better efficiency, which is preferred when the impact orientation is known in advance. Several energy absorbers utilizing different deployment modes could also be combined to optimize overall performance and/or improve system reliability as outlined in the paper. Results from a series of component and full scale demonstration tests are presented as well as typical deployment techniques and mechanisms. LS-DYNA analytical simulations of selected tests are also presented.

  5. Shade Avoidance

    PubMed Central

    Casal, Jorge J.

    2012-01-01

    The presence of neighboring vegetation modifies the light environment experienced by plants, generating signals that are perceived by phytochromes and cryptochromes. These signals cause large changes in plant body form and function, including enhanced growth of the hypocotyl and petioles, a more erect position of the leaves and early flowering in Arabidopsis thaliana. Collectively, these so-called shade-avoidance responses tend to reduce the degree of current or future shade by neighbors. Shade light signals increase the abundance of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5 proteins, promote the synthesis and redirection of auxin, favor the degradation of DELLA proteins and increase the expression of auxin, gibberellins and brassinosteroid-promoted genes, among other events downstream the photoreceptors. Selectively disrupting these events by genetic or pharmacological approaches affects shade-avoidance responses with an intensity that depends on the developmental context and the environment. Shade-avoidance responses provide a model to investigate the signaling networks used by plants to take advantage of the cues provided by the environment to adjust to the challenges imposed by the environment itself. PMID:22582029

  6. To crash or not to crash: how do hoverflies cope with free-fall situations and weightlessness?

    PubMed

    Goulard, Roman; Vercher, Jean-Louis; Viollet, Stéphane

    2016-08-15

    Insects' aptitude to perform hovering, automatic landing and tracking tasks involves accurately controlling their head and body roll and pitch movements, but how this attitude control depends on an internal estimation of gravity orientation is still an open question. Gravity perception in flying insects has mainly been studied in terms of grounded animals' tactile orientation responses, but it has not yet been established whether hoverflies use gravity perception cues to detect a nearly weightless state at an early stage. Ground-based microgravity simulators provide biologists with useful tools for studying the effects of changes in gravity. However, in view of the cost and the complexity of these set-ups, an alternative Earth-based free-fall procedure was developed with which flying insects can be briefly exposed to microgravity under various visual conditions. Hoverflies frequently initiated wingbeats in response to an imposed free fall in all the conditions tested, but managed to avoid crashing only in variably structured visual environments, and only episodically in darkness. Our results reveal that the crash-avoidance performance of these insects in various visual environments suggests the existence of a multisensory control system based mainly on vision rather than gravity perception. PMID:27535987

  7. Crash Tests of Protective Airplane Floors

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1986-01-01

    Energy-absorbing floors reduce structural buckling and impact forces on occupants. 56-page report discusses crash tests of energy-absorbing aircraft floors. Describes test facility and procedures; airplanes, structural modifications, and seats; crash dynamics; floor and seat behavior; and responses of anthropometric dummies seated in airplanes. Also presents plots of accelerations, photographs and diagrams of test facility, and photographs and drawings of airplanes before, during, and after testing.

  8. Marijuana Use and Motor Vehicle Crashes

    PubMed Central

    Li, Mu-Chen; Brady, Joanne E.; DiMaggio, Charles J.; Lusardi, Arielle R.; Tzong, Keane Y.; Li, Guohua

    2012-01-01

    Since 1996, 16 states and the District of Columbia in the United States have enacted legislation to decriminalize marijuana for medical use. Although marijuana is the most commonly detected nonalcohol drug in drivers, its role in crash causation remains unsettled. To assess the association between marijuana use and crash risk, the authors performed a meta-analysis of 9 epidemiologic studies published in English in the past 2 decades identified through a systematic search of bibliographic databases. Estimated odds ratios relating marijuana use to crash risk reported in these studies ranged from 0.85 to 7.16. Pooled analysis based on the random-effects model yielded a summary odds ratio of 2.66 (95% confidence interval: 2.07, 3.41). Analysis of individual studies indicated that the heightened risk of crash involvement associated with marijuana use persisted after adjustment for confounding variables and that the risk of crash involvement increased in a dose-response fashion with the concentration of 11-nor-9-carboxy-delta-9-tetrahydrocannabinol detected in the urine and the frequency of self-reported marijuana use. The results of this meta-analysis suggest that marijuana use by drivers is associated with a significantly increased risk of being involved in motor vehicle crashes. PMID:21976636

  9. Vehicular crash data used to rank intersections by injury crash frequency and severity.

    PubMed

    Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar

    2016-09-01

    This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies.

  10. Vehicular crash data used to rank intersections by injury crash frequency and severity.

    PubMed

    Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar

    2016-09-01

    This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies. PMID:27508245

  11. Do elevated gravitational-force events while driving predict crashes and near crashes?

    PubMed

    Simons-Morton, Bruce G; Zhang, Zhiwei; Jackson, John C; Albert, Paul S

    2012-05-15

    The purpose of this research was to determine the extent to which elevated gravitational-force event rates predict crashes and near crashes. Accelerometers, global positioning systems, cameras, and other technology were installed in vehicles driven by 42 newly licensed Virginia teenage drivers for a period of 18 months between 2006 and 2009. Elevated gravitational force and crash and near-crash events were identified, and rates per miles driven were calculated. (One mile = 1.6 km.) The correlation between crashes and near crashes and elevated gravitational-force event rates was 0.60. Analyses were done by using generalized estimating equations with logistic regression. Higher elevated gravitational-force event rates in the past month substantially increased the risk of a crash in the subsequent month (odds ratio = 1.07, 95% confidence interval: 1.02, 1.12). Although the difference in this relation did not vary significantly by time, it was highest in the first 6 months compared with the second and third 6-month periods. With a receiver operating characteristic curve, the risk models showed relatively high predictive accuracy with an area under the curve of 0.76. The authors conclude that elevated gravitational-force event rates can be used to assess risk and to show high predictive accuracy of a near-future crash.

  12. Thoracolumbar Spine Fractures in Frontal Impact Crashes

    PubMed Central

    Pintar, Frank A.; Yoganandan, Narayan; Maiman, Dennis J.; Scarboro, Mark; Rudd, Rodney W.

    2012-01-01

    There is currently no injury assessment for thoracic or lumbar spine fractures in the motor vehicle crash standards throughout the world. Compression-related thoracolumbar fractures are occurring in frontal impacts and yet the mechanism of injury is poorly understood. The objective of this investigation was to characterize these injuries using real world crash data from the US-DOT-NHTSA NASS-CDS and CIREN databases. Thoracic and lumbar AIS vertebral body fracture codes were searched for in the two databases. The NASS database was used to characterize population trends as a function of crash year and vehicle model year. The CIREN database was used to examine a case series in more detail. From the NASS database there were 2000–4000 occupants in frontal impacts with thoracic and lumbar vertebral body fractures per crash year. There was an increasing trend in incidence rate of thoracolumbar fractures in frontal impact crashes as a function of vehicle model year from 1986 to 2008; this was not the case for other crash types. From the CIREN database, the thoracolumbar spine was most commonly fractured at either the T12 or L1 level. Major, burst type fractures occurred predominantly at T12, L1 or L5; wedge fractures were most common at L1. Most CIREN occupants were belted; there were slightly more females involved; they were almost all in bucket seats; impact location occurred approximately half the time on the road and half off the road. The type of object struck also seemed to have some influence on fractured spine level, suggesting that the crash deceleration pulse may be influential in the type of compression vector that migrates up the spinal column. Future biomechanical studies are required to define mechanistically how these fractures are influenced by these many factors. PMID:23169137

  13. Patterns of Drug Use in Fatal Crashes

    PubMed Central

    Romano, Eduardo; Pollini, Robin A.

    2013-01-01

    Aims To characterize drug prevalence among fatally injured drivers, identify significant associations (i.e., day of week, time of day, age, gender), and compare findings with those for alcohol. Design Descriptive and logistic mixed-model regression analyses of Fatality Analysis Reporting System data. Setting U.S. states with drug test results for >80% of fatally injured drivers, 1998-2010. Participants Drivers killed in single-vehicle crashes on public roads who died at the scene of the crash (N=16,942). Measurements Drug test results, blood alcohol concentration (BAC), gender, age, and day and time of crash. Findings Overall, 45.1% of fatally injured drivers tested positive for alcohol (39.9% BAC>0.08) and 25.9% for drugs. The most common drugs present were stimulants (7.2%) and cannabinols (7.1%), followed by “other” drugs (4.1%), multiple drugs (4.1%), narcotics (2.1%), and depressants (1.5%). Drug-involved crashes occurred with relative uniformity throughout the day while alcohol-involved crashes were more common at night (p<.01). The odds of testing positive for drugs varied depending upon drug class, driver characteristics, time of day, and the presence of alcohol. Conclusions Fatal single vehicle crashes involving drugs are less common than those involving alcohol and the characteristics of drug-involved crashes differ depending upon drug class and whether alcohol is present. Concerns about drug-impaired driving should not detract from the current law enforcement focus on alcohol-impaired driving. PMID:23600629

  14. A History of Full-Scale Aircraft and Rotorcraft Crash Testing and Simulation at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.; Lyle, Karen H.

    2004-01-01

    This paper summarizes 2-1/2 decades of full-scale aircraft and rotorcraft crash testing performed at the Impact Dynamics Research Facility (IDRF) located at NASA Langley Research Center in Hampton, Virginia. The IDRF is a 240-ft.-high steel gantry that was built originally as a lunar landing simulator facility in the early 1960's. It was converted into a full-scale crash test facility for light aircraft and rotorcraft in the early 1970 s. Since the first full-scale crash test was preformed in February 1974, the IDRF has been used to conduct: 41 full-scale crash tests of General Aviation (GA) aircraft including landmark studies to establish baseline crash performance data for metallic and composite GA aircraft; 11 full-scale crash tests of helicopters including crash qualification tests of the Bell and Sikorsky Advanced Composite Airframe Program (ACAP) prototypes; 48 Wire Strike Protection System (WSPS) qualification tests of Army helicopters; 3 vertical drop tests of Boeing 707 transport aircraft fuselage sections; and, 60+ crash tests of the F-111 crew escape module. For some of these tests, nonlinear transient dynamic codes were utilized to simulate the impact response of the airframe. These simulations were performed to evaluate the capabilities of the analytical tools, as well as to validate the models through test-analysis correlation. In September 2003, NASA Langley closed the IDRF facility and plans are underway to demolish it in 2007. Consequently, it is important to document the contributions made to improve the crashworthiness of light aircraft and rotorcraft achieved through full-scale crash testing and simulation at the IDRF.

  15. A regional review of air medical transports for fatal motor vehicle crashes.

    PubMed

    Garthe, E A; Mango, N K; Prenney, B

    2000-01-01

    This article presents study results from an assessment of the performance of the air medical (and advanced life support) components of the EMS system in response to fatal motor vehicle crashes. Results are presented for one of Massachusetts' five EMS regions, including the finding that air medical transports are involved in 20% of the fatal crashes for the region and transport 11% of the involved individuals. Although the study focused on air medical utilization, it also identified issues related to the future implementation of motor vehicle automatic crash notification (ACN) and telematics that could relay crash severity data from onboard computers (e.g., event data recorders) to auto manufacturers' help centers or state emergency call centers. This technology will place new demands on state EMS systems. To meet the challenges posed by these technological changes, states will need to assess the type and number of EMS services required to respond to ACN motor vehicle crashes and develop methods to determine what level of service to deploy based on the information relayed from the vehicles. An initial step in this evaluation process is to determine the current use of EMS resources to place planned system changes and demand into context.

  16. In-depth analysis of drivers' merging behavior and rear-end crash risks in work zone merging areas.

    PubMed

    Weng, Jinxian; Xue, Shan; Yang, Ying; Yan, Xuedong; Qu, Xiaobo

    2015-04-01

    This study investigates the drivers' merging behavior and the rear-end crash risk in work zone merging areas during the entire merging implementation period from the time of starting a merging maneuver to that of completing the maneuver. With the merging traffic data from a work zone site in Singapore, a mixed probit model is developed to describe the merging behavior, and two surrogate safety measures including the time to collision (TTC) and deceleration rate to avoid the crash (DRAC) are adopted to compute the rear-end crash risk between the merging vehicle and its neighboring vehicles. Results show that the merging vehicle has a bigger probability of completing a merging maneuver quickly under one of the following situations: (i) the merging vehicle moves relatively fast; (ii) the merging lead vehicle is a heavy vehicle; and (iii) there is a sizable gap in the adjacent through lane. Results indicate that the rear-end crash risk does not monotonically increase as the merging vehicle speed increases. The merging vehicle's rear-end crash risk is also affected by the vehicle type. There is a biggest increment of rear-end crash risk if the merging lead vehicle belongs to a heavy vehicle. Although the reduced remaining distance to work zone could urge the merging vehicle to complete a merging maneuver quickly, it might lead to an increased rear-end crash risk. Interestingly, it is found that the rear-end crash risk could be generally increased over the elapsed time after the merging maneuver being triggered.

  17. The role of sleepiness, sleep disorders, and the work environment on heavy-vehicle crashes in 2 Australian states.

    PubMed

    Stevenson, Mark R; Elkington, Jane; Sharwood, Lisa; Meuleners, Lynn; Ivers, Rebecca; Boufous, Soufiane; Williamson, Ann; Haworth, Narelle; Quinlan, Michael; Grunstein, Ron; Norton, Robyn; Wong, Keith

    2014-03-01

    Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investigated the associations of sleepiness, sleep disorders, and work environment (including truck characteristics) with the risk of crashing between 2008 and 2011 in the Australian states of New South Wales and Western Australia. We conducted a case-control study of 530 heavy-vehicle drivers who had recently crashed and 517 heavy-vehicle drivers who had not. Drivers' crash histories, truck details, driving schedules, payment rates, sleep patterns, and measures of health were collected. Subjects wore a nasal flow monitor for 1 night to assess for obstructive sleep apnea. Driving schedules that included the period between midnight and 5:59 am were associated with increased likelihood of crashing (odds ratio = 3.42, 95% confidence interval: 2.04, 5.74), as were having an empty load (odds ratio = 2.61, 95% confidence interval: 1.72, 3.97) and being a less experienced driver (odds ratio = 3.25, 95% confidence interval: 2.37, 4.46). Not taking regular breaks and the lack of vehicle safety devices were also associated with increased crash risk. Despite the high prevalence of obstructive sleep apnea, it was not associated with the risk of a heavy-vehicle nonfatal, nonsevere crash. Scheduling of driving to avoid midnight-to-dawn driving and the use of more frequent rest breaks are likely to reduce the risk of heavy-vehicle nonfatal, nonsevere crashes by 2-3 times.

  18. The role of sleepiness, sleep disorders, and the work environment on heavy-vehicle crashes in 2 Australian states.

    PubMed

    Stevenson, Mark R; Elkington, Jane; Sharwood, Lisa; Meuleners, Lynn; Ivers, Rebecca; Boufous, Soufiane; Williamson, Ann; Haworth, Narelle; Quinlan, Michael; Grunstein, Ron; Norton, Robyn; Wong, Keith

    2014-03-01

    Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investigated the associations of sleepiness, sleep disorders, and work environment (including truck characteristics) with the risk of crashing between 2008 and 2011 in the Australian states of New South Wales and Western Australia. We conducted a case-control study of 530 heavy-vehicle drivers who had recently crashed and 517 heavy-vehicle drivers who had not. Drivers' crash histories, truck details, driving schedules, payment rates, sleep patterns, and measures of health were collected. Subjects wore a nasal flow monitor for 1 night to assess for obstructive sleep apnea. Driving schedules that included the period between midnight and 5:59 am were associated with increased likelihood of crashing (odds ratio = 3.42, 95% confidence interval: 2.04, 5.74), as were having an empty load (odds ratio = 2.61, 95% confidence interval: 1.72, 3.97) and being a less experienced driver (odds ratio = 3.25, 95% confidence interval: 2.37, 4.46). Not taking regular breaks and the lack of vehicle safety devices were also associated with increased crash risk. Despite the high prevalence of obstructive sleep apnea, it was not associated with the risk of a heavy-vehicle nonfatal, nonsevere crash. Scheduling of driving to avoid midnight-to-dawn driving and the use of more frequent rest breaks are likely to reduce the risk of heavy-vehicle nonfatal, nonsevere crashes by 2-3 times. PMID:24352592

  19. Predicting crash risk and identifying crash precursors on Korean expressways using loop detector data.

    PubMed

    Kwak, Ho-Chan; Kho, Seungyoung

    2016-03-01

    In order to improve traffic safety on expressways, it is important to develop proactive safety management strategies with consideration for segment types and traffic flow states because crash mechanisms have some differences by each condition. The primary objective of this study is to develop real-time crash risk prediction models for different segment types and traffic flow states on expressways. The mainline of expressways is divided into basic segment and ramp vicinity, and the traffic flow states are classified into uncongested and congested conditions. Also, Korean expressways have irregular intervals between loop detector stations. Therefore, we investigated on the effect and application of the detector stations at irregular intervals for the crash risk prediction on expressways. The most significant traffic variables were selected by conditional logistic regression analysis which could control confounding factors. Based on the selected traffic variables, separate models to predict crash risk were developed using genetic programming technique. The model estimation results showed that the traffic flow characteristics leading to crashes are differed by segment type and traffic flow state. Especially, the variables related to the intervals between detector stations had a significant influence on crash risk prediction under the uncongested condition. Finally, compared with the single model for all crashes and the logistic models used in previous studies, the proposed models showed higher prediction performance. The results of this study can be applied to develop more effective proactive safety management strategies for different segment types and traffic flow states on expressways with loop detector stations at irregular intervals. PMID:26710266

  20. Predicting crash risk and identifying crash precursors on Korean expressways using loop detector data.

    PubMed

    Kwak, Ho-Chan; Kho, Seungyoung

    2016-03-01

    In order to improve traffic safety on expressways, it is important to develop proactive safety management strategies with consideration for segment types and traffic flow states because crash mechanisms have some differences by each condition. The primary objective of this study is to develop real-time crash risk prediction models for different segment types and traffic flow states on expressways. The mainline of expressways is divided into basic segment and ramp vicinity, and the traffic flow states are classified into uncongested and congested conditions. Also, Korean expressways have irregular intervals between loop detector stations. Therefore, we investigated on the effect and application of the detector stations at irregular intervals for the crash risk prediction on expressways. The most significant traffic variables were selected by conditional logistic regression analysis which could control confounding factors. Based on the selected traffic variables, separate models to predict crash risk were developed using genetic programming technique. The model estimation results showed that the traffic flow characteristics leading to crashes are differed by segment type and traffic flow state. Especially, the variables related to the intervals between detector stations had a significant influence on crash risk prediction under the uncongested condition. Finally, compared with the single model for all crashes and the logistic models used in previous studies, the proposed models showed higher prediction performance. The results of this study can be applied to develop more effective proactive safety management strategies for different segment types and traffic flow states on expressways with loop detector stations at irregular intervals.

  1. Drowsy Driving Causes 1 in 5 Fatal Crashes: Report

    MedlinePlus

    ... html Drowsy Driving Causes 1 in 5 Fatal Crashes: Report Teens and young adults, shift-workers and ... day. And, drowsy driving was a factor in crashes that claimed about 5,000 lives last year, ...

  2. Factors Affecting Ejection Risk in Rollover Crashes

    PubMed Central

    Funk, James R.; Cormier, Joseph M.; Bain, Charles E.; Wirth, Jeffrey L.; Bonugli, Enrique B.; Watson, Richard A.

    2012-01-01

    Ejection greatly increases the risk of injury and fatality in a rollover crash. The purpose of this study was to determine the crash, vehicle, and occupant characteristics that affect the risk of ejection in rollovers. Information from real world rollover crashes occurring from 2000 – 2010 was obtained from the National Automotive Sampling System (NASS) in order to analyze the effect of the following parameters on ejection risk: seatbelt use, rollover severity, vehicle type, seating position, roof crush, side curtain airbag deployment, glazing type, and occupant age, gender, and size. Seatbelt use was found to reduce the risk of partial ejection and virtually eliminate the risk of complete ejection. For belted occupants, the risk of partial ejection risk was significantly increased in rollover crashes involving more roof inversions, light trucks and vans (LTVs), and larger occupants. For unbelted occupants, the risk of complete ejection was significantly increased in rollover crashes involving more roof inversions, LTVs, far side occupants, and higher levels of roof crush. Roof crush was not a significant predictor of ejection after normalizing for rollover severity. Curtain airbag deployment was associated with reduced rates of partial and complete ejection, but the effect was not statistically significant, perhaps due to the small sample size (n = 89 raw cases with curtain deployments). A much greater proportion of occupants who were ejected in spite of curtain airbag deployment passed through the sunroof and other portals as opposed to the adjacent side window compared to occupants who were ejected in rollovers without a curtain airbag deployment. The primary factors that reduce ejection risk in rollover crashes are, in generally decreasing order of importance: seatbelt use, fewer roof inversions, passenger car body type, curtain airbag deployment, near side seating position, and small occupant size. PMID:23169130

  3. Factors affecting ejection risk in rollover crashes.

    PubMed

    Funk, James R; Cormier, Joseph M; Bain, Charles E; Wirth, Jeffrey L; Bonugli, Enrique B; Watson, Richard A

    2012-01-01

    Ejection greatly increases the risk of injury and fatality in a rollover crash. The purpose of this study was to determine the crash, vehicle, and occupant characteristics that affect the risk of ejection in rollovers. Information from real world rollover crashes occurring from 2000 - 2010 was obtained from the National Automotive Sampling System (NASS) in order to analyze the effect of the following parameters on ejection risk: seatbelt use, rollover severity, vehicle type, seating position, roof crush, side curtain airbag deployment, glazing type, and occupant age, gender, and size. Seatbelt use was found to reduce the risk of partial ejection and virtually eliminate the risk of complete ejection. For belted occupants, the risk of partial ejection risk was significantly increased in rollover crashes involving more roof inversions, light trucks and vans (LTVs), and larger occupants. For unbelted occupants, the risk of complete ejection was significantly increased in rollover crashes involving more roof inversions, LTVs, far side occupants, and higher levels of roof crush. Roof crush was not a significant predictor of ejection after normalizing for rollover severity. Curtain airbag deployment was associated with reduced rates of partial and complete ejection, but the effect was not statistically significant, perhaps due to the small sample size (n = 89 raw cases with curtain deployments). A much greater proportion of occupants who were ejected in spite of curtain airbag deployment passed through the sunroof and other portals as opposed to the adjacent side window compared to occupants who were ejected in rollovers without a curtain airbag deployment. The primary factors that reduce ejection risk in rollover crashes are, in generally decreasing order of importance: seatbelt use, fewer roof inversions, passenger car body type, curtain airbag deployment, near side seating position, and small occupant size. PMID:23169130

  4. Conscientious personality and young drivers’ crash risk

    PubMed Central

    Ehsani, Johnathon P.; Li, Kaigang; Simons-Morton, Bruce; Tree-McGrath, Cheyenne Fox; Perlus, Jessamyn; O’Brien, Fearghal; Klauer, Sheila G.

    2015-01-01

    Introduction Personality characteristics are associated with many risk behaviors. However, the relationship between personality traits, risky driving behavior, and crash risk is poorly understood. The purpose of this study was to examine the association between personality, risky driving behavior and crashes and near-crashes, using naturalistic driving research methods. Method Participants’ driving exposure, kinematic risky driving (KRD), high-risk secondary task engagement, and the frequency of crashes and near-crashes (CNC) were assessed over the first 18 months of licensure using naturalistic driving methods. A personality survey (NEO-Five Factor Inventory) was administered at baseline. The association between personality characteristics, KRD rate, secondary task engagement rate and CNC rate was estimated using a linear regression model. Mediation analysis was conducted to examine if participants’ KRD rate or secondary task engagement rate mediated the relationship between personality and CNC. Data were collected as part of the Naturalistic Teen Driving Study. Results Conscientiousness was marginally negatively associated with CNC (path c = −0.034, p = .09) and both potential mediators KRD (path a = −0.040, p = .09) and secondary task engagement while driving (path a = −0.053, p = .03). KRD, but not secondary task engagement, was found to mediate (path b = 0.376, p = .02) the relationship between conscientiousness and CNC (path c’ = −0.025, p = .20). Conclusions Using objective measures of driving behavior and a widely used personality construct, these findings present a causal pathway through which personality and risky driving are associated with CNC. Specifically, more conscientious teenage drivers engaged in fewer risky driving maneuvers, suffered fewer CNC. Practical Applications Part of the variability in crash-risk observed among newly licensed teenage drivers can be explained by personality. Parents and driving instructors may take teenage

  5. Origin and Prevention of Crash Fires in Turbojet Aircraft

    NASA Technical Reports Server (NTRS)

    Pinkel, I Irving; Weiss, Solomon; Preston, G Merritt; Pesman, Gerard J

    1957-01-01

    The manner in which the jet engine may start a crash fire was explored in test-stand and full-scale crash studies. On the basis of these studies, a method was devised for inserting and cooling the engine parts that may serve as ignition sources in crash. This method was tried successfully in full-scale crashes of jet-powered airplanes carrying engines in pod nacelles and engines buried within the airplane structure.

  6. Statistical implications of using moving violations to determine crash responsibility in young driver crashes.

    PubMed

    Curry, Allison E; Pfeiffer, Melissa R; Myers, Rachel K; Durbin, Dennis R; Elliott, Michael R

    2014-04-01

    Traditional methods for determining crash responsibility - most commonly moving violation citations - may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these methods do not capture driver behaviors that are not illegal but still indicative of fault. We examined the statistical implications of using moving violations to determine crash responsibility in young driver crashes by comparing it with a method based on crash-contributing driver actions. We selected all drivers in police-reported passenger-vehicle crashes (2010-2011) that involved a New Jersey driver <21 years old (79,485 driverscrash responsibility was determined from the crash report using two alternative methods: (1) issuance of a moving violation citation; and (2) presence of a driver action (e.g., failure to yield, inattention). Overall, 18% of crash-involved drivers were issued a moving violation while 50% had a driver action. Only 32.2% of drivers with a driver action were cited for a moving violation. Further, the likelihood of being cited given the presence of a driver action was higher among certain driver subgroups-younger drivers, male drivers, and drivers in single-vehicle and more severe crashes. Specifically among young drivers, those driving at night, carrying peer passengers, and having a suspended or no license were more often cited. Conversely, fatally-injured drivers were almost never cited. We also demonstrated that using citation data may lead to statistical bias in the characterization of at-fault drivers and of quasi-induced exposure measures. Studies seeking to accurately determine crash responsibility should thoughtfully consider the potential sources of bias that may result from using legal culpability methods. For many studies, determining driver responsibility via the identification of

  7. Statistical implications of using moving violations to determine crash responsibility in young driver crashes

    PubMed Central

    Curry, Allison E.; Pfeiffer, Melissa R.; Myers, Rachel K.; Durbin, Dennis R.; Elliott, Michael R.

    2014-01-01

    Traditional methods for determining crash responsibility—most commonly moving violation citations—may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these methods do not capture driver behaviors that are not illegal but still indicative of fault. We examined the statistical implications of using moving violations to determine crash responsibility in young driver crashes by comparing it with a method based on crash-contributing driver actions. We selected all drivers in police-reported passenger-vehicle crashes (2010–2011) that involved a New Jersey driver <21 years old (79,485 drivers < age 21, 61,355 drivers ≥ age 21.) For each driver, crash responsibility was determined from the crash report using two alternative methods: (1) issuance of a moving violation citation; and (2) presence of a driver action (e.g., failure to yield, inattention). Overall, 18% of crash-involved drivers were issued a moving violation while 50% had a driver action. Only 32.2% of drivers with a driver action were cited for a moving violation. Further, the likelihood of being cited given the presence of a driver action was higher among certain driver subgroups—younger drivers, male drivers, and drivers in single-vehicle and more severe crashes. Specifically among young drivers, those driving at night, carrying peer passengers, and having a suspended or no license were more often cited. Conversely, fatally-injured drivers were almost never cited. We also demonstrated that using citation data may lead to statistical bias in the characterization of at-fault drivers and of quasi-induced exposure measures. Studies seeking to accurately determine crash responsibility should thoughtfully consider the potential sources of bias that may result from using legal culpability methods. For many studies, determining driver responsibility via the identification

  8. Safety impacts of platform tram stops on pedestrians in mixed traffic operation: A comparison group before-after crash study.

    PubMed

    Naznin, Farhana; Currie, Graham; Logan, David; Sarvi, Majid

    2016-01-01

    Tram stops in mixed traffic environments present a variety of safety, accessibility and transport efficiency challenges. In Melbourne, Australia the hundred year-old electric tram system is progressively being modernized to improve passenger accessibility. Platform stops, incorporating raised platforms for level entry into low floor trams, are being retro-fitted system-wide to replace older design stops. The aim of this study was to investigate the safety impacts of platform stops over older design stops (i.e. Melbourne safety zone tram stops) on pedestrians in the context of mixed traffic tram operation in Melbourne, using an advanced before-after crash analysis approach, the comparison group (CG) method. The CG method evaluates safety impacts by taking into account the general trends in safety and the unobserved factors at treatment and comparison sites that can alter the outcomes of a simple before-after analysis. The results showed that pedestrian-involved all injury crashes reduced by 43% after platform stop installation. This paper also explores a concern that the conventional CG method might underestimate safety impacts as a result of large differences in passenger stop use between treatment and comparison sites, suggesting differences in crash risk exposure. To adjust for this, a modified analysis explored crash rates (crash counts per 10,000 stop passengers) for each site. The adjusted results suggested greater reductions in pedestrian-involved crashes after platform stop installation: an 81% reduction in pedestrian-involved all injury crashes and 86% reduction in pedestrian-involved FSI crashes, both are significant at the 95% level. Overall, the results suggest that platform stops have considerable safety benefits for pedestrians. Implications for policy and areas for future research are explored. PMID:26476596

  9. Robotics and Design: An Interdisciplinary Crash Course

    ERIC Educational Resources Information Center

    Bonarini, A.; Romero, M.

    2013-01-01

    The authors designed and ran a crash course on emotional robotics involving students from both the Information Engineering School and the Design School of Politecnico di Milano, Milan, Italy. The course consisted of two intensive days of short introductory lessons and lab activity, done in interdisciplinary groups and supported by a well-equipped…

  10. Analysis of Large Truck Rollover Crashes

    PubMed Central

    McKnight, A. James; Bahouth, George T.

    2008-01-01

    The Large Truck Crash Causation Study undertaken by the Federal Motor Carrier Safety Administration describes 239 crashes in which a truck rolled over. In-depth analysis revealed almost half resulted from failing to adjust speed to curves in the road, (mostly on-and off-ramps), the load being carried, condition of the brakes, road surface, and intersection conditions. A second major crash contributor involved attention: simply being inattentive, dozing or falling asleep, and distraction, all leading to situations where a sudden direction change resulted in a rollover. The third large crash contributor involved steering: over-steering to the point of rolling over, not steering enough to stay in lane, and overcorrecting to the point of having to counter-steer to remain on the road. Finally, loads are a frequent problem when drivers fail to take account of their weight, height or security, or when loading takes place before they are assigned. Instruction in rollover prevention, like most truck driver training, comes through printed publications. The use of video would help drivers recognize incipient rollovers while currently available simulation would allow drivers to experience the consequences of mistakes without risk. PMID:19026244

  11. Survivors’ experiences from a train crash

    PubMed Central

    Saveman, Britt-Inger

    2011-01-01

    Rarely described are people's lived experiences from severe injury events such as train crashes. The number of train crashes named disasters with ≥10 killed and/or ≥100 nonfatally injured grows globally and the trend shows that more people survive these disasters today than did so in the past. This results in an increased number of survivors needing care. The aim of the study was to explore survivors’ experiences from a train crash. Narrative interviews were performed with 14 passengers 4 years after a train crash event. Qualitative content analysis was used to analyse the interviews. Experiences were captured in three main themes: (1) Living in the mode of existential threat describes how the survivors first lost control, then were thrown into a state of unimaginable chaos as they faced death. (2) Dealing with the unthinkable described how survivors restored control, the central role of others, and the importance of reconstructing the event to move forward in their processing. (3) Having cheated death shows how some became shackled by their history, whereas others overcame the haunting of unforgettable memories. Furthermore, the result shows how all experienced a second chance in life. Experiencing a train crash meant that the passengers experienced severe vulnerability and a threat to life and interdependence turned out to play a crucial role. Focusing on helping other passengers on site was one way to regain the loss of control and kept the chaos at bay. Family, friends, and fellow passengers turned out to be extremely important during the recovery process why such closeness should be promoted and facilitated. PMID:22125573

  12. Defining and screening crash surrogate events using naturalistic driving data.

    PubMed

    Wu, Kun-Feng; Jovanis, Paul P

    2013-12-01

    Naturalistic driving studies provide an excellent opportunity to better understand crash causality and to supplement crash observations with a much larger number of near crash events. The goal of this research is the development of a set of diagnostic procedures to define, screen, and identify crash and near crash events that can be used in enhanced safety analyses. A way to better understand crash occurrence and identify potential countermeasures to improve safety is to learn from and use near crash events, particularly those near crashes that have a common etiology to crash outcomes. This paper demonstrates that a multi-stage modeling framework can be used to search through naturalistic driving data, extracting statistically similar crashes and near crashes. The procedure is tested using data from the VTTI 100-car study for road departure events. A total of 63 events are included in this application. While the sample size is limited in this empirical study, the authors believe the procedure is ready for testing in other applications.

  13. The Pattern of Road Traffic Crashes in South East Iran

    PubMed Central

    Rad, Mahdieh; Martiniuk, Alexandra LC.; Ansari-Moghaddam, Alireza; Mohammadi, Mahdi; Rashedi, Fariborz; Ghasemi, Ardavan

    2016-01-01

    Background: In the present study, the epidemiologic aspects of road traffic crashes in South East of Iran are described. Methods: This cross-sectional study included the profile of 2398 motor vehicle crashes recorded in the police office in one Year in South East of Iran. Data collected included: demographics, the type of crash, type of involved vehicle, location of crash and factors contributing to the crash. Descriptive statistics were used for data analysis. Results: Collisions with other vehicles or objects contributed the highest proportion (62.4%) of motor vehicle crashes. Human factors including careless driving, violating traffic laws, speeding, and sleep deprivation/fatigue were the most important causal factors accounting for 90% of road crashes. Data shows that 41% of drivers were not using a seat belt at the time of crash. One- third of the crashes resulted in injury (25%) or death (5%). Conclusions: Reckless driving such as speeding and violation of traffic laws are major risk factors for crashes in the South East of Iran. This highlights the need for education along with traffic law enforcement to reduce motor vehicle crashes in future. PMID:27157159

  14. Optimization of Car Body under Constraints of Noise, Vibration, and Harshness (NVH), and Crash

    NASA Technical Reports Server (NTRS)

    Kodiyalam, Srinivas; Yang, Ren-Jye; Sobieszczanski-Sobieski, Jaroslaw (Editor)

    2000-01-01

    approximation model while keeping the Crash response surface constant. In every outer loop, the Crash response surface approximation is updated, including a gradual increase in the order of the response surface and the response surface extension in the direction of the search. In this optimization task, the NVH discipline has 30 design variables while the crash discipline has 20 design variables. A subset of these design variables (10) are common to both the NVH and crash disciplines. In order to construct a linear response surface for the Crash discipline constraints, a minimum of 21 design points would have to be analyzed using the RADIOSS code. On a single processor in Origin 2000 that amount of computing would require over 9 months! In this work, these runs were carried out concurrently on the Origin 2000 using multiple processors, ranging from 8 to 16, for each crash (RADIOSS) analysis. Another figure shows the wall time required for a single RADIOSS analysis using varying number of processors, as well as provides a comparison of 2 different common data placement procedures within the allotted memories for each analysis. The initial design is an infeasible design with NVH discipline Static Torsion constraint violations of over 10%. The final optimized design is a feasible design with a weight reduction of 15 kg compared to the initial design. This work demonstrates how advanced methodology for optimization combined with the technology of concurrent processing enables applications that until now were out of reach because of very long time-to-solution.

  15. Disparities in road crash mortality among pedestrians using wheelchairs in the USA: results of a capture–recapture analysis

    PubMed Central

    Kraemer, John D; Benton, Connor S

    2015-01-01

    Objective This study aims to quantify and describe the burden of fatal pedestrian crashes among persons using wheelchairs in the USA from 2006 to 2012. Design The occurrence of fatal pedestrian crashes among pedestrians using wheelchairs was assessed using two-source capture-recapture. Descriptive analysis of fatal crashes was conducted using customary approaches. Setting Two registries were constructed, both of which likely undercounted fatalities among pedestrians who use wheelchairs. The first used data from the Fatality Analysis Reporting System, and the second used a LexisNexis news search. Outcome measures Mortality rate (per 100 000 person-years) and crash-level, driver-level and pedestrian-level characteristics of fatal crashes. Results This study found that, from 2006 to 2012, the mortality rate for pedestrians using wheelchairs was 2.07/100 000 person-years (95% CI 1.60 to 2.54), which was 36% higher than the overall population pedestrian mortality rate (p=0.02). Men's risk was over fivefold higher than women's risk (p<0.001). Compared to the overall population, persons aged 50–64 using wheelchairs had a 38% increased risk (p=0.04), and men who use wheelchairs aged 50–64 had a 75% increased risk over men of the same age in the overall population (p=0.006). Almost half (47.6%; 95% CI 42.8 to 52.5) of fatal crashes occurred in intersections and 38.7% (95% CI 32.0 to 45.0) of intersection crashes occurred at locations without traffic control devices. Among intersection crashes, 47.5% (95% CI 40.6 to 54.5) involved wheelchair users in a crosswalk; no crosswalk was available for 18.3% (95% CI 13.5 to 24.4). Driver failure to yield right-of-way was noted in 21.4% (95% CI 17.7 to 25.7) of crashes, and no crash avoidance manoeuvers were detected in 76.4% (95% CI 71.0 to 81.2). Conclusions Persons who use wheelchairs experience substantial pedestrian mortality disparities calling for behavioural and built environment interventions. PMID:26589426

  16. Defective equipment and tractor-trailer crash involvement.

    PubMed

    Jones, I S; Stein, H S

    1989-10-01

    The role of defective equipment in large truck crashes on interstate highways in Washington State was investigated using a case-control study design. For each large truck involved in a crash, three trucks were randomly selected from the traffic stream at the same time and place as the crash, but one week later both crash and comparison trucks were inspected by Commercial Vehicle Enforcement officers of the Washington State Patrol. The effects of truck equipment condition, truck operating characteristics (carrier type, carrier operation, and truck load), and driver characteristics (driver age, hours of driving) on crash involvement were analyzed by comparing their relative frequency among crash-involved and comparison sample tractor-trailers. A logistic regression model was used to estimate the adjusted odds ratio for each factor. Overall, 77% of tractor-trailers in crashes and 66% of those not involved in crashes had defective equipment warranting a citation. Forty-one percent in crashes had defective equipment warranting taking the truck out of service, and 31% not in crashes had these defects. Brake defects were the most common type and were found in 56% of tractor-trailers in crashes; steering equipment defects were found in 21%. The relative risk of crash involvement for trucks with brake defects was about one and one-half times that for trucks without brake defects. For trucks with steering defects, the relative risk of crash involvement was at least twice that for trucks with steering defects, the relative risk of crash involvement was at least twice that for trucks without defects, and the risk increased substantially for trucks with out-of-service steering defects.

  17. Crash Injury Prediction and Vehicle Damage Reporting by Paramedics

    PubMed Central

    Vaca, Federico E.; Anderson, Craig L.; Herrera, Harold; Patel, Chirag; Silman, Eric F.; DeGuzman, Rhian; Lahham, Shadi; Kohl, Vanessa

    2009-01-01

    Objective: The accuracy of pre-hospital crash scene details and crash victim assessment has important implications for initial trauma care assessment and management. Similarly, it is known to influence physician perception of crash victim injury severity. The goal of this feasibility study was to examine paramedic accuracy in predicting crash victim injury profile, disability outcome at hospital discharge, and reporting vehicle damage with other crash variables. Methods: This prospective case series study was undertaken at a Southern California, Level I trauma center certified by the American College of Surgeons. Paramedics transporting crash injured motor vehicle occupants to our emergency department (ED)/trauma center were surveyed. We abstracted ED and in-patient records of injured vehicle occupants. Vehicle and crash scene data were obtained from a professional crash reconstruction, which included the assessment of deformation, crash forces, change in velocity, and the source of each injury. Results: We used survey, injury, and crash reconstruction data from 22 collision cases in the final analysis. The median Injury Severity Score (ISS) was five (range 1–24). No enrolled patients died, and none were severely disabled at the time of discharge from the hospital. The paramedic crash injury severity predictions were sensitive for an Abbreviated Injury Scale (AIS) of 2–4. Paramedics often agreed with the crash reconstruction on restraint use, ejection, and other fatalities at the scene, and had lower levels of agreement for front airbag deployment, steering wheel damage, and window/windshield impact. Paramedics had 80% accuracy in predicting any disability at the time of hospital discharge. Conclusion: Paramedic prediction of injury profile was sensitive, and prediction of disability outcome at discharge was accurate when compared to discharge diagnosis. Their reporting of vehicle specific crash variables was less accurate. Further study should be undertaken to

  18. Cost and benefit estimates of partially-automated vehicle collision avoidance technologies.

    PubMed

    Harper, Corey D; Hendrickson, Chris T; Samaras, Constantine

    2016-10-01

    Many light-duty vehicle crashes occur due to human error and distracted driving. Partially-automated crash avoidance features offer the potential to reduce the frequency and severity of vehicle crashes that occur due to distracted driving and/or human error by assisting in maintaining control of the vehicle or issuing alerts if a potentially dangerous situation is detected. This paper evaluates the benefits and costs of fleet-wide deployment of blind spot monitoring, lane departure warning, and forward collision warning crash avoidance systems within the US light-duty vehicle fleet. The three crash avoidance technologies could collectively prevent or reduce the severity of as many as 1.3 million U.S. crashes a year including 133,000 injury crashes and 10,100 fatal crashes. For this paper we made two estimates of potential benefits in the United States: (1) the upper bound fleet-wide technology diffusion benefits by assuming all relevant crashes are avoided and (2) the lower bound fleet-wide benefits of the three technologies based on observed insurance data. The latter represents a lower bound as technology is improved over time and cost reduced with scale economies and technology improvement. All three technologies could collectively provide a lower bound annual benefit of about $18 billion if equipped on all light-duty vehicles. With 2015 pricing of safety options, the total annual costs to equip all light-duty vehicles with the three technologies would be about $13 billion, resulting in an annual net benefit of about $4 billion or a $20 per vehicle net benefit. By assuming all relevant crashes are avoided, the total upper bound annual net benefit from all three technologies combined is about $202 billion or an $861 per vehicle net benefit, at current technology costs. The technologies we are exploring in this paper represent an early form of vehicle automation and a positive net benefit suggests the fleet-wide adoption of these technologies would be beneficial

  19. Cost and benefit estimates of partially-automated vehicle collision avoidance technologies.

    PubMed

    Harper, Corey D; Hendrickson, Chris T; Samaras, Constantine

    2016-10-01

    Many light-duty vehicle crashes occur due to human error and distracted driving. Partially-automated crash avoidance features offer the potential to reduce the frequency and severity of vehicle crashes that occur due to distracted driving and/or human error by assisting in maintaining control of the vehicle or issuing alerts if a potentially dangerous situation is detected. This paper evaluates the benefits and costs of fleet-wide deployment of blind spot monitoring, lane departure warning, and forward collision warning crash avoidance systems within the US light-duty vehicle fleet. The three crash avoidance technologies could collectively prevent or reduce the severity of as many as 1.3 million U.S. crashes a year including 133,000 injury crashes and 10,100 fatal crashes. For this paper we made two estimates of potential benefits in the United States: (1) the upper bound fleet-wide technology diffusion benefits by assuming all relevant crashes are avoided and (2) the lower bound fleet-wide benefits of the three technologies based on observed insurance data. The latter represents a lower bound as technology is improved over time and cost reduced with scale economies and technology improvement. All three technologies could collectively provide a lower bound annual benefit of about $18 billion if equipped on all light-duty vehicles. With 2015 pricing of safety options, the total annual costs to equip all light-duty vehicles with the three technologies would be about $13 billion, resulting in an annual net benefit of about $4 billion or a $20 per vehicle net benefit. By assuming all relevant crashes are avoided, the total upper bound annual net benefit from all three technologies combined is about $202 billion or an $861 per vehicle net benefit, at current technology costs. The technologies we are exploring in this paper represent an early form of vehicle automation and a positive net benefit suggests the fleet-wide adoption of these technologies would be beneficial

  20. Occupant Responses in a Full-Scale Crash Test of the Sikorsky ACAP Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; McEntire, Joseph; Lewis, Alan

    2002-01-01

    A full-scale crash test of the Sikorsky Advanced Composite Airframe Program (ACAP) helicopter was performed in 1999 to generate experimental data for correlation with a crash simulation developed using an explicit nonlinear, transient dynamic finite element code. The airframe was the residual flight test hardware from the ACAP program. For the test, the aircraft was outfitted with two crew and two troop seats, and four anthropomorphic test dummies. While the results of the impact test and crash simulation have been documented fairly extensively in the literature, the focus of this paper is to present the detailed occupant response data obtained from the crash test and to correlate the results with injury prediction models. These injury models include the Dynamic Response Index (DRI), the Head Injury Criteria (HIC), the spinal load requirement defined in FAR Part 27.562(c), and a comparison of the duration and magnitude of the occupant vertical acceleration responses with the Eiband whole-body acceleration tolerance curve.

  1. Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; Lyle, Karen H.

    2003-01-01

    A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

  2. Database improvements for motor vehicle/bicycle crash analysis

    PubMed Central

    Lusk, Anne C; Asgarzadeh, Morteza; Farvid, Maryam S

    2015-01-01

    Background Bicycling is healthy but needs to be safer for more to bike. Police crash templates are designed for reporting crashes between motor vehicles, but not between vehicles/bicycles. If written/drawn bicycle-crash-scene details exist, these are not entered into spreadsheets. Objective To assess which bicycle-crash-scene data might be added to spreadsheets for analysis. Methods Police crash templates from 50 states were analysed. Reports for 3350 motor vehicle/bicycle crashes (2011) were obtained for the New York City area and 300 cases selected (with drawings and on roads with sharrows, bike lanes, cycle tracks and no bike provisions). Crashes were redrawn and new bicycle-crash-scene details were coded and entered into the existing spreadsheet. The association between severity of injuries and bicycle-crash-scene codes was evaluated using multiple logistic regression. Results Police templates only consistently include pedal-cyclist and helmet. Bicycle-crash-scene coded variables for templates could include: 4 bicycle environments, 18 vehicle impact-points (opened-doors and mirrors), 4 bicycle impact-points, motor vehicle/bicycle crash patterns, in/out of the bicycle environment and bike/relevant motor vehicle categories. A test of including these variables suggested that, with bicyclists who had minor injuries as the control group, bicyclists on roads with bike lanes riding outside the lane had lower likelihood of severe injuries (OR, 0.40, 95% CI 0.16 to 0.98) compared with bicyclists riding on roads without bicycle facilities. Conclusions Police templates should include additional bicycle-crash-scene codes for entry into spreadsheets. Crash analysis, including with big data, could then be conducted on bicycle environments, motor vehicle potential impact points/doors/mirrors, bicycle potential impact points, motor vehicle characteristics, location and injury. PMID:25835304

  3. Survey of NASA research on crash dynamics

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Carden, H. D.; Hayduk, R. J.

    1984-01-01

    Ten years of structural crash dynamics research activities conducted on general aviation aircraft by the National Aeronautics and Space Administration (NASA) are described. Thirty-two full-scale crash tests were performed at Langley Research Center, and pertinent data on airframe and seat behavior were obtained. Concurrent with the experimental program, analytical methods were developed to help predict structural behavior during impact. The effects of flight parameters at impact on cabin deceleration pulses at the seat/occupant interface, experimental and analytical correlation of data on load-limiting subfloor and seat configurations, airplane section test results for computer modeling validation, and data from emergency-locator-transmitter (ELT) investigations to determine probable cause of false alarms and nonactivations are assessed. Computer programs which provide designers with analytical methods for predicting accelerations, velocities, and displacements of collapsing structures are also discussed.

  4. Pilot ejection, parachute, and helicopter crash injuries.

    PubMed

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem.

  5. Burn injuries from small airplane crashes.

    PubMed

    Moye, S J; Cruse, C W; Watkins, G M

    1991-11-01

    Because a large amount of general aviation activity occurs in Central Florida, we reviewed our admissions for victims of small airplane crashes. We identified 13 burn victims of small aircraft accidents over a 7-year period. Of the 13, 12 survived their burn injuries, an overall survival rate of 92%. The extent of burn injury, Abbreviated Burn Severity Index (ABSI), complications, other injuries and rehabilitation potential are reviewed. Burn injury resulting from small airplane crashes is usually survivable if the patient arrives at the Burn Center alive. These burn victims generally are highly motivated individuals, are easily rehabilitated, and continue productive lives. Small airports and local hospitals should be aware of burn center availability because of the usual major extent of the burn injury.

  6. Pilot ejection, parachute, and helicopter crash injuries.

    PubMed

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. PMID:25399374

  7. Safer Roadside Crash Walls Would Limit Deceleration

    NASA Technical Reports Server (NTRS)

    Schneider, William C.; Locke, James P.

    2003-01-01

    The figure depicts the aspects of a proposed deceleration-limiting design for crash walls at the sides of racetracks and highways. The proposal is intended to overcome the disadvantages of both rigid barriers and kinetic-energy-absorbing barriers of prior design. Rigid barriers can keep high-speed crashing motor vehicles from leaving roadways and thereby prevent injury to nearby persons and objects, but they can also subject the occupants of the vehicles to deceleration levels high enough to cause injury or death. Kinetic-energy-absorbing barriers of prior design reduce deceleration levels somewhat, but are not designed to soften impacts optimally; moreover, some of them allow debris to bounce back onto roadways or onto roadside areas, and, in cases of glancingly incident vehicles, some of them can trap the vehicles in such a manner as to cause more injury than would occur if the vehicles were allowed to skid along the rigid barriers. The proposed crash walls would (1) allow tangentially impacting vehicles to continue sliding along the racetrack without catching them, (2) catch directly impacting vehicles to prevent them from injuring nearby persons and objects, and (3) absorb kinetic energy in a more nearly optimum way to limit decelerations to levels that human occupants could survive.

  8. Dynamic model for automotive side impact crashes

    NASA Astrophysics Data System (ADS)

    Sun, Ludong; Taghvaeeyan, Saber; Rajamani, Rajesh

    2014-07-01

    A rigid body model to represent a side impact crash is constructed using five degrees-of-freedom (dof) for the vehicle and three dof for each occupant in the vehicle. Nonlinear stiffness and damping elements and the presence of physical gaps between several components make the model highly nonlinear. The model is validated using experimental crash test data from a National Highway Traffic Safety Administration (NHTSA) database. To simplify the parameter identification process and reduce the number of parameters to be identified at each stage, a two-step process is adopted in which the vehicle is first assumed to be unaffected by the presence of the occupants, and its model parameters are identified. Subsequently, the parameters in the occupant models are identified. The active set method with a performance index that includes both the L2 and L∞ norms is used for parameter identification. A challenge is posed by the fact that the optimisation problem involved is non-convex. To overcome this challenge, a large set of random initial values of parameter estimates is generated and the optimisation method is applied with all these initial conditions. The values of parameters that provide the minimal performance index from the entire set of initial conditions are then chosen as the best parameter values. The optimal parameters values thus identified are shown to significantly improve the match between the model responses and the experimentally measured sensor signals from the NHTSA crash test.

  9. Biomechanics of under ride motor vehicle crashes.

    PubMed

    Kumar, Sri; Sances, Anthony; Enz, Bruce; Frieder, Russell

    2007-01-01

    The present study evaluates the biomechanical aspects of injuries sustained by occupants of passenger cars during collisions with the trailer portion of a tractor/trailer rig. In such collisions, the occupants of the passenger car often sustain serious injuries when the passenger car passes beneath the trailer. This process by which the car "underrides" the trailer occurs due to the mismatch in height between the lowermost edge of the trailer and the crash mitigation structures in the vehicle. The study outlines a car-to-trailer crash testing methodology used to determine the effectiveness of one potential trailer underride guard in preventing serious injuries to occupants of passenger cars. The results from initial crash tests suggest that occupants of cars that collide with the unguarded sides of trailers are at a high risk of serious injury to the head, neck, and chest due the large intrusion of the roof and roof support structures into the occupant compartment. Testing of a trailer fitted with an underride guard showed that occupants of vehicles that collide with the sides of trailers that have been modified to engage the energy absorbing structures of passenger cars are exposed to a smaller risk of injury.

  10. Teachers Avoiding Learners' Avoidance: Is It Possible?

    ERIC Educational Resources Information Center

    Tadayyon, Maedeh; Zarrinabadi, Nourollah; Ketabi, Saeed

    2016-01-01

    Dealing with learners who prefer to take the back seat and avoid classroom participation can be every teacher's nightmare. This lack of participation may cause teacher frustration, and possibly the only way to reduce this lack of participation is to access the concept of avoidance strategy. Avoidance strategy is the abandonment of a classroom task…

  11. The Stock Market Crashes of 1929 and 1987: Linking History and Personal Finance Education

    ERIC Educational Resources Information Center

    Lopus, Jane S.

    2005-01-01

    This article discusses two twentieth-century stock market crashes: the crash of 1929 and the crash of 1987. When this material is presented to students, they see important parallels between the two historical events. But despite remarkable similarities in the severity and many other aspects of the two crashes, the crash of 1929 was followed by the…

  12. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false To whom do we send crash... MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  13. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false To whom do we send crash... MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  14. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false To whom do we send crash... MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  15. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false To whom do we send crash... MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  16. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false To whom do we send crash... MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  17. Identifying critical road geometry parameters affecting crash rate and crash type.

    PubMed

    Othman, Sarbaz; Thomson, Robert; Lannér, Gunnar

    2009-10-01

    The objective of this traffic safety investigation was to find critical road parameters affecting crash rate (CR). The study was based on crash and road maintenance data from Western Sweden. More than 3000 crashes, reported from 2000 to 2005 on median-separated roads, were collected and combined with road geometric and surface data. The statistical analysis showed variations in CR when road elements changed confirming that road characteristics affect CR. The findings indicated that large radii right-turn curves were more dangerous than left curves, in particular, during lane changing manoeuvres. However sharper curves are more dangerous in both left and right curves. Moreover, motorway carriageways with no or limited shoulders have the highest CR when compared to other carriageway widths, while one lane carriageway sections on 2+1 roads were the safest. Road surface results showed that both wheel rut depth and road roughness have negative impacts on traffic safety.

  18. A tree-structured crash surrogate measure for freeways.

    PubMed

    Kuang, Yan; Qu, Xiaobo; Wang, Shuaian

    2015-04-01

    In this paper, we propose a novel methodology to define and estimate a surrogate measure. By imposing a hypothetical disturbance to the leading vehicle, the following vehicle's action is represented as a probabilistic causal model. After that, a tree is built to describe the eight possible conflict types under the model. The surrogate measure, named Aggregated Crash Index (ACI), is thus proposed to measure the crash risk. This index reflects the accommodability of freeway traffic state to a traffic disturbance. We further apply this measure to evaluate the crash risks in a freeway section of Pacific Motorway, Australia. The results show that the proposed indicator outperforms the three traditional crash surrogate measures (i.e., Time to Collision, Proportion of Stopping Distance, and Crash Potential Index) in representing rear-end crash risks. The applications of this measure are also discussed.

  19. Factors Leading to Crash Fatalities to Children in Child Restraints

    PubMed Central

    Sherwood, Christopher P.; Ferguson, Susan A.; Crandall, Jeff R.

    2003-01-01

    Efforts to improve child restraint designs would benefit from more detailed information on how child occupants are dying in crashes. Detailed reports involving 92 children (ages 5 and younger) in child restraints who died in crashes in 2000 were obtained from police departments. Cases were reviewed to obtain basic crash information and determine the factor most responsible for the fatality. Half of the crashes were considered unsurvivable for the child, and 12 percent of fatalities were judged to result from gross misuse of the child restraint. Forty percent of all of the crashes were side impacts, and in all fatal side impact crashes there was intrusion at the child’s seating position. PMID:12941235

  20. Mechanism of Start and Development of Aircraft Crash Fires

    NASA Technical Reports Server (NTRS)

    Pinkel, I. Irving; Preston, G. Merritt; Pesman, Gerard J.

    1952-01-01

    Full-scale aircraft crashes were made to investigate the mechanism of the start and development of aircraft crash fires. The results are discussed herein. This investigation revealed the characteristics of the ignition sources, the manner in which the combustibles spread, the mechanism of the union of the combustibles and ignition sources, and the pertinent factors governing the development of a crash fire as observed in this program.

  1. Mechanism of Start and Development of Aircraft Crash Fires

    NASA Technical Reports Server (NTRS)

    Pinkel, I. Irving; Preston, G. Merritt; Pesman, Gerard J.

    1952-01-01

    Full-scale aircraft crashes, devised to give surge fuel spillage and a high incidence of fire, were made to investigate the mechanism of the start and development of aircraft crash fires. The results are discussed. herein. This investigation revealed the characteristics of the ignition sources, the manner in which the combustibles spread., the mechanism of the union of the combustibles and ignition sources, and the pertinent factors governing the development of a crash fire as observed in this program.

  2. Effects of forming history on crash simulation of a vehicle

    NASA Astrophysics Data System (ADS)

    Gökler, M. İ.; Doğan, U. Ç.; Darendeliler, H.

    2016-08-01

    The effects of forming on the crash simulation of a vehicle have been investigated by considering the load paths produced by sheet metal forming process. The frontal crash analysis has been performed by the finite element method, firstly without considering the forming history, to find out the load paths that absorb the highest energy. The sheet metal forming simulations have been realized for each structural component of the load paths and the frontal crash analysis has been repeated by including forming history. The results of the simulations with and without forming effects have been compared with the physical crash test results available in literature.

  3. Externality of risk and crash severity at roundabouts.

    PubMed

    Daniels, Stijn; Brijs, Tom; Nuyts, Erik; Wets, Geert

    2010-11-01

    The severity of 1491 crashes on 148 roundabouts in Flanders-Belgium was examined in order to investigate which factors might explain the severity of crashes or injuries and to relate these factors to the existing knowledge about contributing factors for injury severity in traffic. Logistic regression and hierarchical binomial logistic regression techniques were used. A clear externality of risk appeared to be present in the sense that vulnerable road user groups (pedestrians, bicyclists, moped riders and motorcyclists) are more severely affected than others. Fatalities or serious injuries in multiple-vehicle crashes for drivers of four-wheel vehicles are much rarer. Injury severity increases with higher age. Crashes at night and crashes outside built-up areas are more severe. Single-vehicle crashes seem to have more severe outcomes than multiple-vehicle crashes. However, systematic differences in the reporting rate of crashes are likely to exist and may have affected the stated results. Correlations with important, but unobserved variables like the impact speeds in the crashes might exist as well and could provide an alternative explanation for some results.

  4. Offsite radiological consequence analysis for the bounding aircraft crash accident

    SciTech Connect

    OBERG, B.D.

    2003-03-22

    The purpose of this calculation note is to quantitatively analyze a bounding aircraft crash accident for comparison to the DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', Appendix A, Evaluation Guideline of 25 rem. The potential of aircraft impacting a facility was evaluated using the approach given in DOE-STD-3014-96, ''Accident Analysis for Aircraft Crash into Hazardous Facilities''. The following aircraft crash frequencies were determined for the Tank Farms in RPP-11736, ''Assessment Of Aircraft Crash Frequency For The Hanford Site 200 Area Tank Farms'': (1) The total aircraft crash frequency is ''extremely unlikely.'' (2) The general aviation crash frequency is ''extremely unlikely.'' (3) The helicopter crash frequency is ''beyond extremely unlikely.'' (4) For the Hanford Site 200 Areas, other aircraft type, commercial or military, each above ground facility, and any other type of underground facility is ''beyond extremely unlikely.'' As the potential of aircraft crash into the 200 Area tank farms is more frequent than ''beyond extremely unlikely,'' consequence analysis of the aircraft crash is required.

  5. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    PubMed

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  6. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    PubMed

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  7. Do Crashes and Near Crashes in Simulator-Based Training Enhance Novice Drivers’ Visual Search for Latent Hazards?

    PubMed Central

    Vlakveld, Willem; Romoser, Matthew R. E.; Mehranian, Hasmik; Diete, Frank; Pollatsek, Alexander; Fisher, Donald L.

    2012-01-01

    Young drivers (younger than 25 years of age) are overrepresented in crashes. Research suggests that a relevant cause is inadequate visual search for possible hazards that are hidden from view. The objective of this study was to develop and evaluate a low-cost, fixed-base simulator training program that would address this failure. It was hypothesized that elicited crashes in the simulator training would result in better scanning for latent hazards in scenarios that were similar to the training scenarios but situated in a different environment (near transfer), and, to a lesser degree, would result in better scanning in scenarios that had altogether different latent hazards than those contained in the training scenarios (far transfer). To test the hypotheses, 18 trained and 18 untrained young novice drivers were evaluated on an advanced driving simulator (different from the training simulator). The eye movements of both groups were measured. In near transfer scenarios, trained drivers fixated the hazardous region 84% of the time, compared with only 57% of untrained drivers. In far transfer scenarios, trained drivers fixated the hazardous region 71 % of the time, compared with only 53% of untrained drivers. The differences between trained and untrained drivers in both the near transfer scenarios and the far transfer scenarios were significant, with a large effect size in the near transfer scenarios and a medium effect size in the far transfer scenarios [respectively: U = 63.00, p(2-tailed) < .01, r = −.53, and U = 88.00, p(2-tailed)<.05,r = −.39]. PMID:23082041

  8. Traffic crash liability determination: Danger and Dodge model.

    PubMed

    Xu, Sikui; Huang, Helai

    2016-10-01

    By proposing a systematic set of rules for traffic crash liability determination, this paper attempts to prove the feasibility and practicability of legal liability in handling traffic crashes. Two sequential elements are identified for crash occurrence, i.e., the occurrence of a dangerous situation and failure in dodging the dangerous situation. A Danger and Dodge model is subsequently established for liability determination in a traffic crash. By investigating the basic mechanism of a crash occurrence, the specific contents of causalties and the effect of the parties' acts in traffic crashes are specified. Based on the theories of social adequancy, the principle of reliance and the duty of care, the study further proposes to use the "peril" of a dangerous situation and the "possibility" of dodging the dangerous situation to appraise the effect of the parties' acts upon a crash occurrence, with the rule of the "pattern deciding effect". The proposed approach would be very helpful to the concreteness of the determination of liability in a traffic crash. Two case studies are presented for demonstration.

  9. Analyzing angle crashes at unsignalized intersections using machine learning techniques.

    PubMed

    Abdel-Aty, Mohamed; Haleem, Kirolos

    2011-01-01

    A recently developed machine learning technique, multivariate adaptive regression splines (MARS), is introduced in this study to predict vehicles' angle crashes. MARS has a promising prediction power, and does not suffer from interpretation complexity. Negative Binomial (NB) and MARS models were fitted and compared using extensive data collected on unsignalized intersections in Florida. Two models were estimated for angle crash frequency at 3- and 4-legged unsignalized intersections. Treating crash frequency as a continuous response variable for fitting a MARS model was also examined by considering the natural logarithm of the crash frequency. Finally, combining MARS with another machine learning technique (random forest) was explored and discussed. The fitted NB angle crash models showed several significant factors that contribute to angle crash occurrence at unsignalized intersections such as, traffic volume on the major road, the upstream distance to the nearest signalized intersection, the distance between successive unsignalized intersections, median type on the major approach, percentage of trucks on the major approach, size of the intersection and the geographic location within the state. Based on the mean square prediction error (MSPE) assessment criterion, MARS outperformed the corresponding NB models. Also, using MARS for predicting continuous response variables yielded more favorable results than predicting discrete response variables. The generated MARS models showed the most promising results after screening the covariates using random forest. Based on the results of this study, MARS is recommended as an efficient technique for predicting crashes at unsignalized intersections (angle crashes in this study).

  10. Innovative Anti Crash Absorber for a Crashworthy Landing Gear

    NASA Astrophysics Data System (ADS)

    Guida, Michele; Marulo, Francesco; Montesarchio, Bruno; Bruno, Massimiliano

    2014-06-01

    This paper defines an innovative concept to anti-crash absorber in composite material to be integrated on the landing gear as an energy-absorbing device in crash conditions to absorb the impact energy. A composite cylinder tube in carbon fiber material is installed coaxially to the shock absorber cylinder and, in an emergency landing gear condition, collapses in order to enhance the energy absorption performance of the landing system. This mechanism has been developed as an alternative solution to a high-pressure chamber installed on the Agusta A129 CBT helicopter, which can be considered dangerous when the helicopter operates in hard and/or crash landing. The characteristics of the anti-crash device are presented and the structural layout of a crashworthy landing gear adopting the developed additional energy absorbing stage is outlined. Experimental and numerical results relevant to the material characterization and the force peaks evaluation of the system development are reported. The anti-crash prototype was designed, analysed, optimized, made and finally the potential performances of a landing gear with the additional anti-crash absorber system are tested by drop test and then correlated with a similar test without the anti-crash system, showing that appreciable energy absorbing capabilities and efficiencies can be obtained in crash conditions.

  11. Determining older driver crash responsibility from police and insurance data.

    PubMed

    Langford, Jim; Koppel, Sjaanie; Andrea, Dale; Fildes, Brian

    2006-12-01

    This study aimed to determine the extent to which older drivers can be considered responsible for their crashes, to identify key factors in those crashes for which older drivers have been judged responsible, and to assess the extent to which older drivers' extra crash responsibility contributes to the road toll. Insurance claims from the State of Tasmania, Australia, for 1998-2002 were linked with police records for crashes involving drivers aged either 41-55 years or 65 years or older. Insurance and police data sets contained independent judgments of crash responsibility. There was a high level of agreement between the two sets of judgments, with older drivers judged around 1.5 times more likely to be responsible for their crashes than middle-aged drivers and, conversely, older drivers were around 0.6 as likely to be absolved from crash responsibility. It was concluded that older drivers' additional crash responsibility while valuable in explaining "what went wrong," currently makes only a small contribution to the overall road toll.

  12. Risk factors for fatal crashes in rural Australia.

    PubMed

    Siskind, Victor; Steinhardt, Dale; Sheehan, Mary; O'Connor, Teresa; Hanks, Heather

    2011-05-01

    This paper presents findings from the rural and remote road safety study, conducted in Queensland, Australia, from March 2004 till June 2007, and compares fatal crashes and non-fatal but serious crashes in respect of their environmental, vehicle and operator factors. During the study period there were 613 non-fatal crashes resulting in 684 hospitalised casualties and 119 fatal crashes resulting in 130 fatalities. Additional information from police sources was available on 103 fatal and 309 non-fatal serious crashes. Over three quarters of both fatal and hospitalised casualties were male and the median age in both groups was 34 years. Fatal crashes were more likely to involve speed, alcohol and violations of road rules and fatal crash victims were 2½ times more likely to be unrestrained inside the vehicle than non-fatal casualties, consistent with current international evidence. After controlling for human factors, vehicle and road conditions made a minimal contribution to the seriousness of the crash outcome. Targeted interventions to prevent fatalities on rural and remote roads should focus on reducing speed and drink driving and promoting seatbelt wearing. PMID:21376905

  13. Rayleigh-Taylor instability simulations with CRASH

    NASA Astrophysics Data System (ADS)

    Chou, C.-C.; Fryxell, B.; Drake, R. P.

    2012-03-01

    CRASH is a code package developed for the predictive study of radiative shocks. It is based on the BATSRUS MHD code used extensively for space-weather research. We desire to extend the applications of this code to the study of hydrodynamically unstable systems. We report here the results of Rayleigh-Taylor instability (RTI) simulations with CRASH, as a necessary step toward the study of such systems. Our goal, motivated by the previous comparison of simulations and experiment, is to be able to simulate the magnetic RTI with self-generated magnetic fields produced by the Biermann Battery effect. Here we show results for hydrodynamic RTI, comparing the effects of different solvers and numerical parameters. We find that the early-time behavior converges to the analytical result of the linear theory. We observe that the late-time morphology is sensitive to the numerical scheme and limiter beta. At low-resolution limit, the growth of RTI is highly dependent on the setup and resolution, which we attribute to the large numerical viscosity at low resolution.

  14. Effect of vehicular size on chain-reaction crash

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2015-11-01

    We present the dynamic model of the chain-reaction crash to take account of the vehicular size. Drivers brake according to taillights of the forward vehicle. We investigate the effect of the vehicular size on the chain-reaction crash (multiple-vehicle collision) in the traffic flow controlled by taillights. In the multiple-vehicle collision, the first crash induces more collisions. We investigate how the first collision induces the chain-reaction crash numerically. We derive, analytically, the transition points and the region maps for the chain-reaction crash in the traffic flow of vehicles with finite sizes. We clarify the effect of the vehicular size on the multiple-vehicle collision.

  15. Avoiding the Flu

    MedlinePlus

    ... of this page please turn Javascript on. Feature: Flu Avoiding the Flu Past Issues / Fall 2009 Table of Contents Children ... help avoid getting and passing on the flu. Influenza (Seasonal) The flu is a contagious respiratory illness ...

  16. A reexamination of the small overlap frontal crash.

    PubMed

    Scullion, Paul; Morgan, Richard M; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 - 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 - 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study-following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC-suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  17. Requirements for the Crash Protection of Older Vehicle Passengers

    PubMed Central

    Morris, Andrew; Welsh, Ruth; Hassan, Ahamedali

    2003-01-01

    This study compares injury outcomes in vehicle crashes involving different age groups of belted passengers. Two datasets were considered. Firstly, UK national data revealed that younger passengers are much more likely to be involved in crashes per million miles travelled compared to older passengers although older passengers are much more likely to be killed or seriously injured compared to younger passengers. Secondly, in-depth vehicle crash injury data were examined to determine some of the underlying reasons for the enhanced injury risk amongst older passengers. In crashes of approximately equal severity, the older passenger group were significantly more likely to be fatally injured in frontal crashes (p<0.001). However young passengers were as equally likely to be killed in struck-side crashes compared to the older group. The results also showed that older passengers sustained more serious injuries to the chest region in frontal crashes compared with the younger aged group (p<0.0001) and it is this body region that is particularly problematic. When the data were analysed further, it was found that a large proportion of passengers were female and that in the majority of cases, the seat belt was responsible for injury. Since by the year 2030, 1 in 4 persons will be aged over 65 in most OECD countries, the results suggest a need for intervention through vehicle design including in-vehicle crashworthiness systems that take into account reduced tolerance to impact with ageing. PMID:12941224

  18. Impact of traffic states on freeway crash involvement rates.

    PubMed

    Yeo, Hwasoo; Jang, Kitae; Skabardonis, Alexander; Kang, Seungmo

    2013-01-01

    Freeway traffic accidents are complicated events that are influenced by multiple factors including roadway geometry, drivers' behavior, traffic conditions and environmental factors. Among the various factors, crash occurrence on freeways is supposed to be strongly influenced by the traffic states representing driving situations that are changed by road geometry and cause the change of drivers' behavior. This paper proposes a methodology to investigate the relationship between traffic states and crash involvements on the freeway. First, we defined section-based traffic states: free flow (FF), back of queue (BQ), bottleneck front (BN) and congestion (CT) according to their distinctive patterns; and traffic states of each freeway section are determined based on actual measurements of traffic data from upstream and downstream ends of the section. Next, freeway crash data are integrated with the traffic states of a freeway section using upstream and downstream traffic measurements. As an illustrative study to show the applicability, we applied the proposed method on a 32-mile section of I-880 freeway. By integrating freeway crash occurrence and traffic data over a three-year period, we obtained the crash involvement rate for each traffic state. The results show that crash involvement rate in BN, BQ, and CT states are approximately 5 times higher than the one in FF. The proposed method shows promise to be used for various safety performance measurement including hot spot identification and prediction of the number of crash involvements on freeway sections.

  19. Evaluation of the Second Transport Rotorcraft Airframe Crash Testbed (TRACT 2) Full Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Annett, Martin; Littell, Justin

    2015-01-01

    Two Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the longitudinal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  20. Overview of the Transport Rotorcraft Airframe Crash Testbed (TRACT) Full Scale Crash Tests

    NASA Technical Reports Server (NTRS)

    Annett, Martin; Littell, Justin

    2015-01-01

    The Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate Anthropomorphic Test Devices (ATD) responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 ATDs were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the horizontal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  1. Crash Testing of Helicopter Airframe Fittings

    NASA Technical Reports Server (NTRS)

    Clarke, Charles W.; Townsend, William; Boitnott, Richard

    2004-01-01

    As part of the Rotary Wing Structures Technology Demonstration (RWSTD) program, a surrogate RAH-66 seat attachment fitting was dynamically tested to assess its response to transient, crash impact loads. The dynamic response of this composite material fitting was compared to the performance of an identical fitting subjected to quasi-static loads of similar magnitude. Static and dynamic tests were conducted of both smaller bench level and larger full-scale test articles. At the bench level, the seat fitting was supported in a steel fixture, and in the full-scale tests, the fitting was integrated into a surrogate RAH-66 forward fuselage. Based upon the lessons learned, an improved method to design, analyze, and test similar composite material fittings is proposed.

  2. Crash test for the Copenhagen problem.

    PubMed

    Nagler, Jan

    2004-06-01

    The Copenhagen problem is a simple model in celestial mechanics. It serves to investigate the behavior of a small body under the gravitational influence of two equally heavy primary bodies. We present a partition of orbits into classes of various kinds of regular motion, chaotic motion, escape and crash. Collisions of the small body onto one of the primaries turn out to be unexpectedly frequent, and their probability displays a scale-free dependence on the size of the primaries. The analysis reveals a high degree of complexity so that long term prediction may become a formidable task. Moreover, we link the results to chaotic scattering theory and the theory of leaking Hamiltonian systems. PMID:15244719

  3. Crash test for the Copenhagen problem.

    PubMed

    Nagler, Jan

    2004-06-01

    The Copenhagen problem is a simple model in celestial mechanics. It serves to investigate the behavior of a small body under the gravitational influence of two equally heavy primary bodies. We present a partition of orbits into classes of various kinds of regular motion, chaotic motion, escape and crash. Collisions of the small body onto one of the primaries turn out to be unexpectedly frequent, and their probability displays a scale-free dependence on the size of the primaries. The analysis reveals a high degree of complexity so that long term prediction may become a formidable task. Moreover, we link the results to chaotic scattering theory and the theory of leaking Hamiltonian systems.

  4. Biomechanical analysis and injury prevention in off-highway vehicular crashes - biomed 2010.

    PubMed

    Burton, Joe; Kumar, Sri; Lewis, Paul; Aulerio, Lou D; Kleinberger, Michael; Strickland, Daniel

    2010-01-01

    Traffic safety has significantly improved over the past several decades reducing injury and fatality rates. However, there is a paucity of research effort directed to address the safety issues in off-highway vehicular crashes, specifically the all terrain/utility vehicular crashes. Rollover crashes are severe accidents leading to the increase in fatalities and injuries. The appropriate safety measures to contain occupants in vehicular compartments are crucial in mitigating injuries in rollover crashes. The purpose of this study is to delineate the occupant kinematics in simulated rollover conditions and to evaluate the injury prevention aspects. Two utility/all terrain vehicles were used. Each vehicle was placed on the motorized test equipment in the laboratory. The motorized dynamic rollover test equipment simulated the rollover environment in a controlled manner. Human surrogate models representing 1th percentile female, 50th percentile male and 96th percentile male were utilized in the testing. The multi-phase dynamic testing was conducted to quantify the occupant kinematic responses in foreseeable real world conditions. A total of 39 tests were conducted. The vehicle with belted surrogates was rolled 90 degrees at a roll rate up to 45 degrees/second. The excursion of the head, upper extremity and lower extremities beyond the plane of the vehicular structure was measured and compared between the two vehicles using two onboard cameras and three off-board cameras. Results show that the advanced restraint system with the occupant containment feature significantly reduced the occupant excursion. Such a significant reduction of occupant movement will better protect occupants in rollover off-highway accidents.

  5. U.S. Civil Air Show Crashes, 1993 to 2013

    PubMed Central

    Ballard, Sarah-Blythe; Osorio, Victor B.

    2016-01-01

    This study provides new public health data about U.S. civil air shows. Risk factors for fatalities in civil air show crashes were analyzed. The value of the FIA score in predicting fatal outcomes was evaluated. With the use of the FAA’s General Aviation and Air Taxi Survey and the National Transportation Safety Board’s data, the incidence of civil air show crashes from 1993 to 2013 was calculated. Fatality risk factors for crashes were analyzed by means of regression methods. The FIA index was validated to predict fatal outcomes by using the factors of fire, instrument conditions, and away-from-airport location, and was evaluated through receiver operating characteristic (ROC) curves. The civil air show crash rate was 31 crashes per 1,000 civil air events. Of the 174 civil air show crashes that occurred during the study period, 91 (52%) involved at least one fatality; on average, 1.1 people died per fatal crash. Fatalities were associated with four major risk factors: fire [adjusted odds ratio (AOR) = 7.1, 95% confidence interval (CI) = 2.4 to 20.6, P < .001], pilot error (AOR = 5.2, 95% CI = 1.8 to 14.5, P = .002), aerobatic flight (AOR = 3.6, 95% CI = 1.6 to 8.2, P = .002), and off-airport location (AOR = 3.4, 95% CI = 1.5 to 7.5, P = .003). The area under the FIA score’s ROC curve was 0.71 (95% CI = 0.64 to 0.78). Civil air show crashes were marked by a high risk of fatal outcomes to pilots in aerobatic performances but rare mass casualties. The FIA score was not a valid measurement of fatal risk in civil air show crashes. PMID:27773963

  6. Drug and Alcohol Involvement in Four Types of Fatal Crashes*

    PubMed Central

    Romano, Eduardo; Voas, Robert B.

    2011-01-01

    Objective: The aim of this study was to explore the relationship of drunk and drugged driving to the occurrence of fatal crashes associated with speeding, failure to obey/yield, inattention, and seat belt nonuse. Method: We examined data for fatally injured drivers involved in single-vehicle crashes killed in states in which more than 79% of the drivers were tested for drugs other than alcohol and had a known result. Results: About 25% of the drivers tested positive for drugs, a figure almost double that estimated by the 2007 National Roadside Survey. Cannabinoids and stimulants each contributed to about 23% of the drug-positive results (6% among all fatally injured single-vehicle drivers). Stimulants more than cannabinoids were found to be associated with the four types of crashes under study. Some drugs showed a protective effect over the four crash types under study. Significant interactions between drugs and alcohol were observed. Stimulants contributed to the different types of fatal crashes irrespective of the levels of alcohol consumed by the drivers. Conclusions: This study provides further evidence of a link between drug consumption and fatal crashes. It also opens the door to some interesting and sometimes unexpected questions regarding the way drugs contribute to crashes, which we found varies depending on the type of crash considered, the class of drug, and the presence of alcohol. Research is also needed on drugs that could have a protective effect on the occurrence of fatal crashes. These findings could be highly relevant to the design of drug-related traffic laws and programs targeted at curbing drugged driving. PMID:21683038

  7. Crash Certification by Analysis - Are We There Yet?

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Lyle, Karen H.

    2006-01-01

    This paper addresses the issue of crash certification by analysis. This broad topic encompasses many ancillary issues including model validation procedures, uncertainty in test data and analysis models, probabilistic techniques for test-analysis correlation, verification of the mathematical formulation, and establishment of appropriate qualification requirements. This paper will focus on certification requirements for crashworthiness of military helicopters; capabilities of the current analysis codes used for crash modeling and simulation, including some examples of simulations from the literature to illustrate the current approach to model validation; and future directions needed to achieve "crash certification by analysis."

  8. Projecting Fatalities in Crashes Involving Older Drivers, 2000-2025

    SciTech Connect

    Hu, P.S.

    2001-03-23

    As part of this research effort, we developed a new methodology for projecting elderly traffic crash fatalities. This methodology separates exposure to crashes from crash risk per se, and further divides exposure into two components, the number of miles driven and the likelihood of being a driver. This component structure permits conceptually different determinants of traffic fatalities to be projected separately and has thorough motivation in behavioral theory. It also permits finer targeting of particular aspects of projections that need improvement and closer linking of projections to possible policy instruments for influencing them.

  9. Evaluation of the First Transport Rotorcraft Airframe Crash Testbed (TRACT 1) Full-Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Littell, Justin D.; Jackson, Karen E.; Bark, Lindley W.; DeWeese, Rick L.; McEntire, B. Joseph

    2014-01-01

    In 2012, the NASA Rotary Wing Crashworthiness Program initiated the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program by obtaining two CH-46E helicopters from the Navy CH-46E Program Office (PMA-226) at the Navy Flight Readiness Center in Cherry Point, North Carolina. Full-scale crash tests were planned to assess dynamic responses of transport-category rotorcraft under combined horizontal and vertical impact loading. The first crash test (TRACT 1) was performed at NASA Langley Research Center's Landing and Impact Research Facility (LandIR), which enables the study of critical interactions between the airframe, seat, and occupant during a controlled crash environment. The CH-46E fuselage is categorized as a medium-lift rotorcraft with fuselage dimensions comparable to a regional jet or business jet. The first TRACT test (TRACT 1) was conducted in August 2013. The primary objectives for TRACT 1 were to: (1) assess improvements to occupant loads and displacement with the use of crashworthy features such as pre-tensioning active restraints and energy absorbing seats, (2) develop novel techniques for photogrammetric data acquisition to measure occupant and airframe kinematics, and (3) provide baseline data for future comparison with a retrofitted airframe configuration. Crash test conditions for TRACT 1 were 33-ft/s forward and 25-ft/s vertical combined velocity onto soft soil, which represent a severe, but potentially survivable impact scenario. The extraordinary value of the TRACT 1 test was reflected by the breadth of meaningful experiments. A total of 8 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and photogrammetric techniques. A combination of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. Loads from ATDs in energy

  10. Structure and dynamics of sawteeth crashes in ASDEX Upgrade

    SciTech Connect

    Igochine, V.; Guenter, S.; Lackner, K.; Pereverzev, G.; Zohm, H.; Boom, J.; Classen, I.; Dumbrajs, O.

    2010-12-15

    The crash phase of the sawteeth in ASDEX Upgrade tokamak [Herrmann et al., Fusion Sci. Technol. 44(3), 569 (2003)] is investigated in detail in this paper by means of soft x-ray (SXR) and electron cyclotron emission (ECE) diagnostics. Analysis of precursor and postcursor (1,1) modes shows that the crash does not affect the position of the resonant surface q=1. Our experimental results suggest that sawtooth crash models should contain two ingredients to be consistent with experimental observations: (1) the (1,1) mode structure should survive the crash and (2) the flux changes should be small to preserve the position of the q=1 surface close to its original location. Detailed structure of the reconnection point was investigated with ECE imaging diagnostic. It is shown that reconnection starts locally. The expelled core is hot which is consistent with SXR tomography results. The observed results can be explained in the framework of a stochastic model.

  11. Structure and dynamics of sawteeth crashes in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Igochine, V.; Boom, J.; Classen, I.; Dumbrajs, O.; Günter, S.; Lackner, K.; Pereverzev, G.; Zohm, H.; ASDEX Upgrade Team

    2010-12-01

    The crash phase of the sawteeth in ASDEX Upgrade tokamak [Herrmann et al., Fusion Sci. Technol. 44(3), 569 (2003)] is investigated in detail in this paper by means of soft x-ray (SXR) and electron cyclotron emission (ECE) diagnostics. Analysis of precursor and postcursor (1,1) modes shows that the crash does not affect the position of the resonant surface q =1. Our experimental results suggest that sawtooth crash models should contain two ingredients to be consistent with experimental observations: (1) the (1,1) mode structure should survive the crash and (2) the flux changes should be small to preserve the position of the q =1 surface close to its original location. Detailed structure of the reconnection point was investigated with ECE imaging diagnostic. It is shown that reconnection starts locally. The expelled core is hot which is consistent with SXR tomography results. The observed results can be explained in the framework of a stochastic model.

  12. Crash in Australian outback ends NASA ballooning season

    NASA Astrophysics Data System (ADS)

    Harris, Margaret

    2010-06-01

    NASA has temporarily suspended all its scientific balloon launches after the balloon-borne Nuclear Compton Tele scope (NCT) crashed during take-off, scattering a trail of debris across the remote launch site and overturning a nearby parked car.

  13. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    PubMed

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes. PMID:26448333

  14. Chain-reaction crash in traffic flow controlled by taillights

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2015-02-01

    We study the chain-reaction crash (multiple-vehicle collision) in low-visibility condition on a road. In the traffic situation, drivers brake according to taillights of the forward vehicle. The first crash may induce more collisions. We investigate whether or not the first collision induces the chain-reaction crash, numerically and analytically. The dynamic transitions occur from no collisions through a single collision, double collisions and triple collisions, to multiple collisions with decreasing the headway. Also, we find that the dynamic transition occurs from the finite chain reaction to the infinite chain reaction when the headway is less than the critical value. We derive, analytically, the transition points and the region maps for the chain-reaction crash in traffic flow controlled by taillights.

  15. Relationship between organisational safety culture dimensions and crashes.

    PubMed

    Varmazyar, Sakineh; Mortazavi, Seyed Bagher; Arghami, Shirazeh; Hajizadeh, Ebrahim

    2016-01-01

    Knowing about organisational safety culture in public transportation system can provide an appropriate guide to establish effective safety measures and interventions to improve safety at work. The aim of this study was investigation of association between safety culture dimensions (leadership styles and company values, usage of crashes information and prevention programmes, management commitment and safety policy, participation and control) with involved self-reported crashes. The associations were considered through Spearman correlation, Pearson chi-square test and logistic regression. The results showed an association among self-reported crashes (occurrence or non-occurrence) and factors including leadership styles and company values; management commitment and safety policy; and control. Moreover, it was found a negative correlation and an odds ratio less than one between control and self-reported crashes.

  16. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights

    PubMed Central

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes. PMID:26448333

  17. Relationship between organisational safety culture dimensions and crashes.

    PubMed

    Varmazyar, Sakineh; Mortazavi, Seyed Bagher; Arghami, Shirazeh; Hajizadeh, Ebrahim

    2016-01-01

    Knowing about organisational safety culture in public transportation system can provide an appropriate guide to establish effective safety measures and interventions to improve safety at work. The aim of this study was investigation of association between safety culture dimensions (leadership styles and company values, usage of crashes information and prevention programmes, management commitment and safety policy, participation and control) with involved self-reported crashes. The associations were considered through Spearman correlation, Pearson chi-square test and logistic regression. The results showed an association among self-reported crashes (occurrence or non-occurrence) and factors including leadership styles and company values; management commitment and safety policy; and control. Moreover, it was found a negative correlation and an odds ratio less than one between control and self-reported crashes. PMID:25494102

  18. ELT antenna gain distributions under simulated crash conditions

    NASA Technical Reports Server (NTRS)

    Estep, H.

    1984-01-01

    A study of the relative merits of ELT antenna positions, when mounted on a small aircraft, is presented. The gain distribution of the best antenna position together with the worst crash scenario is also given.

  19. Heavy Vehicle Crash Characteristics in Oman 2009–2011

    PubMed Central

    Al-Bulushi, Islam; Edwards, Jason; Davey, Jeremy; Armstrong, Kerry; Al-Reesi, Hamed; Al-Shamsi, Khalid

    2015-01-01

    In recent years, Oman has seen a shift in the burden of diseases towards road accidents. The main objective of this paper, therefore, is to describe key characteristics of heavy vehicle crashes in Oman and identify the key driving behaviours that influence fatality risks. Crash data from January 2009 to December 2011 were examined and it was found that, of the 22,543 traffic accidents that occurred within this timeframe, 3,114 involved heavy vehicles. While the majority of these crashes were attributed to driver behaviours, a small proportion was attributed to other factors. The results of the study indicate that there is a need for a more thorough crash investigation process in Oman. Future research should explore the reporting processes used by the Royal Oman Police, cultural influences on heavy vehicle operations in Oman and improvements to the current licensing system. PMID:26052451

  20. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    PubMed

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes.

  1. Helicopter crash in water: effects of simulator escape training.

    PubMed

    Hytten, K

    1989-01-01

    Findings are presented from an interview study of five crew members who survived a helicopter crash. Four of the five surviving men had received simulated helicopter accident training prior to the crash. One untrained crew member died. The four previously trained survivors claimed that the training was of decisive moment in their escape and survival. Contributions from training appeared to be provision of confidence and thought control. The author discusses these as the development of a positive response-outcome expectancy.

  2. Pilot Age and Error in Air-Taxi Crashes

    PubMed Central

    Rebok, George W.; Qiang, Yandong; Baker, Susan P.; Li, Guohua

    2010-01-01

    Introduction The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air-taxi crashes. Methods Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Results Of the 1751 air-taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air-taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Conclusions Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air-taxi crashes. Lack of age-related differences in pilot error may be attributable to the “safe worker effect.” PMID:19601508

  3. Light Airplane Crash Test at Three Pitch Angles

    NASA Technical Reports Server (NTRS)

    Vaughan, Victor L., Jr.; Alfaro-Bou, Emilio

    1979-01-01

    Three similar twin-engine general-aviation airplane specimens were crash tested at the Langley Impact Dynamics Research Facility at 27 m/sec, a flight-path angle of -15deg, and pithch angles of -15deg, 0deg, and 15deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  4. Spatial analysis of fatal and injury crashes in Pennsylvania.

    PubMed

    Aguero-Valverde, Jonathan; Jovanis, Paul P

    2006-05-01

    Using injury and fatal crash data for Pennsylvania for 1996-2000, full Bayes (FB) hierarchical models (with spatial and temporal effects and space-time interactions) are compared to traditional negative binomial (NB) estimates of annual county-level crash frequency. Covariates include socio-demographics, weather conditions, transportation infrastructure and amount of travel. FB hierarchical models are generally consistent with the NB estimates. Counties with a higher percentage of the population under poverty level, higher percentage of their population in age groups 0-14, 15-24, and over 64 and those with increased road mileage and road density have significantly increased crash risk. Total precipitation is significant and positive in the NB models, but not significant with FB. Spatial correlation, time trend, and space-time interactions are significant in the FB injury crash models. County-level FB models reveal the existence of spatial correlation in crash data and provide a mechanism to quantify, and reduce the effect of, this correlation. Addressing spatial correlation is likely to be even more important in road segment and intersection-level crash models, where spatial correlation is likely to be even more pronounced.

  5. Fatal motorcycle crashes: a growing public health problem in Cambodia.

    PubMed

    Roehler, Douglas R; Ear, Chariya; Parker, Erin M; Sem, Panhavuth; Ballesteros, Michael F

    2015-01-01

    This study examines the risk characteristics of fatal motorcycle crashes in Cambodia over a 5-year period (2007-2011). Secondary data analyses were conducted using the Cambodia Road Crash and Victim Information System, the only comprehensive and integrated road crash surveillance system in the country. Researchers from the Centers for Disease Control and Prevention and Handicap International found that (1) males are dying in motorcycle crashes roughly seven times more frequently than females; (2) motorcyclist fatalities increased by about 30% from 2007 to 2011; (3) the motorcyclist death rates per 100,000 population increased from 7.4 to 8.7 deaths from 2007 to 2011; and (4) speed-related crashes and not wearing motorcycle helmet were commonly reported for motorcyclist fatalities at approximately 50% and over 80% through the study years, respectively. Additionally, this study highlights that Cambodia has the highest motorcycle death rate in South-East Asia, far surpassing Thailand, Malaysia, and Myanmar. By recognising the patterns of fatal motorcycle crashes in Cambodia, local road-safety champions and stakeholders can design targeted interventions and preventative measures to improve road safety among motorcyclists.

  6. Three Cases of Spine Fractures after an Airplane Crash

    PubMed Central

    Lee, Han Joo; Moon, Bong Ju; Pennant, William A.; Shin, Dong Ah; Kim, Keung Nyun; Yoon, Do Heum

    2015-01-01

    While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings. PMID:27169094

  7. Fatal motorcycle crashes: a growing public health problem in Cambodia.

    PubMed

    Roehler, Douglas R; Ear, Chariya; Parker, Erin M; Sem, Panhavuth; Ballesteros, Michael F

    2015-01-01

    This study examines the risk characteristics of fatal motorcycle crashes in Cambodia over a 5-year period (2007-2011). Secondary data analyses were conducted using the Cambodia Road Crash and Victim Information System, the only comprehensive and integrated road crash surveillance system in the country. Researchers from the Centers for Disease Control and Prevention and Handicap International found that (1) males are dying in motorcycle crashes roughly seven times more frequently than females; (2) motorcyclist fatalities increased by about 30% from 2007 to 2011; (3) the motorcyclist death rates per 100,000 population increased from 7.4 to 8.7 deaths from 2007 to 2011; and (4) speed-related crashes and not wearing motorcycle helmet were commonly reported for motorcyclist fatalities at approximately 50% and over 80% through the study years, respectively. Additionally, this study highlights that Cambodia has the highest motorcycle death rate in South-East Asia, far surpassing Thailand, Malaysia, and Myanmar. By recognising the patterns of fatal motorcycle crashes in Cambodia, local road-safety champions and stakeholders can design targeted interventions and preventative measures to improve road safety among motorcyclists. PMID:24499413

  8. Car insurance and the risk of car crash injury.

    PubMed

    Blows, Stephanie; Ivers, Rebecca Q; Connor, Jennie; Ameratunga, Shanthi; Norton, Robyn

    2003-11-01

    Despite speculation about the role of vehicle insurance in road traffic accidents, there is little research estimating the direction or extent of the risk relationship. Data from the Auckland Car Crash Injury Study (1998-1999) were used to examine the association between driving an uninsured motor vehicle and car crash injury. Cases were all cars involved in crashes in which at least one occupant was hospitalized or killed anywhere in the Auckland region. Controls were 588 drivers of randomly selected cars on Auckland roads. Participants completed a structured interview. Uninsured drivers had significantly greater odds of car crash injury compared to insured drivers after adjustment for age, sex, level of education, and driving exposure (odds ratio 4.77, 95% confidence interval 2.94-7.75). The causal mechanism for insurance and car crash injury is not easily determined. Although we examined the effects of multiple potential confounders in our analysis including socioeconomic status and risk-taking behaviours, both of which have been previously observed to be associated with both insurance status and car crash injury, residual confounding may partly explain this association. The estimated proportion of drivers who are uninsured is between 5 and 15% in developed countries, representing a significant public health problem worthy of further investigation. PMID:12971933

  9. Higher Crash and Near-Crash Rates in Teenaged Drivers With Lower Cortisol Response

    PubMed Central

    Ouimet, Marie Claude; Brown, Thomas G.; Guo, Feng; Klauer, Sheila G.; Simons-Morton, Bruce G.; Fang, Youjia; Lee, Suzanne E.; Gianoulakis, Christina; Dingus, Thomas A.

    2014-01-01

    IMPORTANCE Road traffic crashes are one of the leading causes of injury and death among teenagers worldwide. Better understanding of the individual pathways to driving risk may lead to better-targeted intervention in this vulnerable group. OBJECTIVE To examine the relationship between cortisol, a neurobiological marker of stress regulation linked to risky behavior, and driving risk. DESIGN, SETTING, AND PARTICIPANTS The Naturalistic Teenage Driving Study was designed to continuously monitor the driving behavior of teenagers by instrumenting vehicles with kinematic sensors, cameras, and a global positioning system. During 2006–2008, a community sample of 42 newly licensed 16-year-old volunteer participants in the United States was recruited and driving behavior monitored. It was hypothesized in teenagers that higher cortisol response to stress is associated with (1) lower crash and near-crash (CNC) rates during their first 18 months of licensure and (2) faster reduction in CNC rates over time. MAIN OUTCOMES AND MEASURES Participants’ cortisol response during a stress-inducing task was assessed at baseline, followed by measurement of their involvement in CNCs and driving exposure during their first 18 months of licensure. Mixed-effect Poisson longitudinal regression models were used to examine the association between baseline cortisol response and CNC rates during the follow-up period. RESULTS Participants with a higher baseline cortisol response had lower CNC rates during the follow-up period (exponential of the regression coefficient, 0.93; 95%CI, 0.88–0.98) and faster decrease in CNC rates over time (exponential of the regression coefficient, 0.98; 95%, CI, 0.96–0.99). CONCLUSIONS AND RELEVANCE Cortisol is a neurobiological marker associated with teenaged-driving risk. As in other problem-behavior fields, identification of an objective marker of teenaged-driving risk promises the development of more personalized intervention approaches. PMID:24710522

  10. Wealth inhomogeneity applied to crash rate theory.

    PubMed

    Shuler, Robert L

    2015-11-01

    A crash rate theory based on corporate economic utility maximization is applied to individual behavior in U.S. and German motorway death rates, by using wealth inhomogeneity data in ten-percentile bins to account for variations of utility maximization in the population. Germany and the U.S. have similar median wealth figures, a well-known indicator of accident risk, but different motorway death rates. It is found that inhomogeneity in roughly the 10(th) to 30(th) percentile, not revealed by popular measures such as the Gini index which focus on differences at the higher percentiles, provides a satisfactory explanation of the data. The inhomogeneity analysis reduces data disparity from a factor of 2.88 to 1.75 as compared with median wealth assumed homogeneity, and further to 1.09 with average wealth assumed homogeneity. The first reduction from 2.88 to 1.75 is attributable to inequality at lower percentiles and suggests it may be as important in indicating socioeconomic risk as extremes in the upper percentile ranges, and that therefore the U.S. socioeconomic risk may be higher than generally realized. PMID:27441226

  11. Aircraft crash caused by stress corrosion cracking

    SciTech Connect

    Kolkman, H.J.; Kool, G.A.; Wanhill, R.J.H.

    1996-01-01

    An aircraft crash in the Netherlands was caused by disintegration of a jet engine. Fractography showed that the chain of events started with stress corrosion cracking (SCC) of a pin attached to a lever arm of the compressor variable vane system. Such a lever arm-pin assembly costs only a few dollars. Investigation of hundreds of pins from the accident and a number of identical engines revealed that this was not an isolated case. Many pins exhibited various amounts of SCC. The failed pin in the accident engine happened to be the first fractured one. SCC requires the simultaneous presence of tensile stress, a corrosive environment, and a susceptible material. In this case the stress was a residual stress arising from the production method. There was a clear correlation between the presence of salt deposits on the levers and SCC of the pins. It was shown that these deposits were able to reach the internal space between the pin and lever arm, thereby initiating SCC in this space. The corrosive environment in Western Europe explains why the problem manifested itself in the Netherlands at a relatively early stage in engine life. The main point is, however, that the manufacturer selected an SCC-prone material in the design stage. The solution has been to change the pin material.

  12. Front blind spot crashes in Hong Kong.

    PubMed

    Cheng, Yuk Ki; Wong, Koon Hung; Tao, Chi Hang; Tam, Cheok Ning; Tam, Yiu Yan; Tsang, Cheuk Nam

    2016-09-01

    In 2012-2014, our laboratory had investigated a total of 9 suspected front blind spot crashes, in which the medium and heavy goods vehicles pulled away from rest and rolled over the pedestrians, who were crossing immediately in front of the vehicles. The drivers alleged that they did not see any pedestrians through the windscreens or the front blind spot mirrors. Forensic assessment of the goods vehicles revealed the existence of front blind spot zones in 3 out of these 9 accident vehicles, which were attributed to the poor mirror adjustments or even the absence of a front blind spot mirror altogether. In view of this, a small survey was devised involving 20 randomly selected volunteers and their goods vehicles and 5 out of these vehicles had blind spots at the front. Additionally, a short questionnaire was conducted on these 20 professional lorry drivers and it was shown that most of them were not aware of the hazards of blind spots immediately in front of their vehicles, and many did not use the front blind spot mirrors properly. A simple procedure for quick measurements of the coverage of front blind spot mirrors using a coloured plastic mat with dimensional grids was also introduced and described in this paper.

  13. Cervical injuries suffered in automobile crashes.

    PubMed

    Huelke, D F; O'Day, J; Mendelsohn, R A

    1981-03-01

    The National Crash Severity Study data in which occupants sustained severe, critical-to-life, or fatal cervical injuries were reviewed. Of passenger cars damaged severely enough to be towed from the scene, it is estimated that one in 300 occupants sustained a neck injury of a severe nature. The neck-injury rate rose to one in 14 occupants for those ejected from their cars, although many of these injuries resulted from contacts within the car before or during the process of ejection. Severe neck injuries were rather rare in cars struck in the rear, but were more common in frontal and side impacts. Occupants between 16 and 25 years of age had such injuries more than twice as often as those in any other age group. Most of the neck injuries of a more severe nature involved the cervical spine or spinal cord. Injuries of the anterior aspect of the neck were relatively infrequent, and usually resulted from direct blunt impacts. National projections of the number of fatalities related to cervical injuries indicates that 5940 deaths, or approximately 20% of all in-car deaths, include fatal cervical spine injuries, and that about 500 cases of quadriplegia per year result from automobile accidents. PMID:7463132

  14. Flight-crash events in turbulence.

    PubMed

    Xu, Haitao; Pumir, Alain; Falkovich, Gregory; Bodenschatz, Eberhard; Shats, Michael; Xia, Hua; Francois, Nicolas; Boffetta, Guido

    2014-05-27

    The statistical properties of turbulence differ in an essential way from those of systems in or near thermal equilibrium because of the flux of energy between vastly different scales at which energy is supplied and at which it is dissipated. We elucidate this difference by studying experimentally and numerically the fluctuations of the energy of a small fluid particle moving in a turbulent fluid. We demonstrate how the fundamental property of detailed balance is broken, so that the probabilities of forward and backward transitions are not equal for turbulence. In physical terms, we found that in a large set of flow configurations, fluid elements decelerate faster than accelerate, a feature known all too well from driving in dense traffic. The statistical signature of rare "flight-crash" events, associated with fast particle deceleration, provides a way to quantify irreversibility in a turbulent flow. Namely, we find that the third moment of the power fluctuations along a trajectory, nondimensionalized by the energy flux, displays a remarkable power law as a function of the Reynolds number, both in two and in three spatial dimensions. This establishes a relation between the irreversibility of the system and the range of active scales. We speculate that the breakdown of the detailed balance characterized here is a general feature of other systems very far from equilibrium, displaying a wide range of spatial scales.

  15. Crash protection for children in ambulances.

    PubMed

    Bull, M J; Weber, K; Talty, J; Manary, M

    2001-01-01

    The objectives of the study were to determine the most effective and reliable means of restraining children on an ambulance cot and to develop recommended field procedures for emergency medical service providers. A series of crash tests at 48 km/h were conducted using convertible child restraints, car beds, and harness systems tested with 3-year, infant, and 6-year size dummies. Belt configuration and backrest position were varied. A new cot and fastener system significantly improved restraint performance over older systems previously tested. A two-belt attachment with elevated cot backrest was found to be the method with the least performance variability for securing either a convertible child restraint or a car bed. It was concluded that children who weight up to 18 kg, fit in a convertible child restraint, and can tolerate a semi-upright seated position can be restrained in a convertible child restraint secured with two belts to an ambulance cot. Infants who must lie flat can be restrained in a car bed modified for two seatbelt paths and secured to a cot. In each case, the cot backrest must be elevated, and the cot and anchor system must be crashworthy. None of the harness configurations tested proved to be satisfactory, but an effective system could be developed by following accepted restraint design principles. PMID:12214360

  16. Wealth inhomogeneity applied to crash rate theory.

    PubMed

    Shuler, Robert L

    2015-11-01

    A crash rate theory based on corporate economic utility maximization is applied to individual behavior in U.S. and German motorway death rates, by using wealth inhomogeneity data in ten-percentile bins to account for variations of utility maximization in the population. Germany and the U.S. have similar median wealth figures, a well-known indicator of accident risk, but different motorway death rates. It is found that inhomogeneity in roughly the 10(th) to 30(th) percentile, not revealed by popular measures such as the Gini index which focus on differences at the higher percentiles, provides a satisfactory explanation of the data. The inhomogeneity analysis reduces data disparity from a factor of 2.88 to 1.75 as compared with median wealth assumed homogeneity, and further to 1.09 with average wealth assumed homogeneity. The first reduction from 2.88 to 1.75 is attributable to inequality at lower percentiles and suggests it may be as important in indicating socioeconomic risk as extremes in the upper percentile ranges, and that therefore the U.S. socioeconomic risk may be higher than generally realized.

  17. Modeling Composite Laminate Crushing for Crash Analysis

    NASA Technical Reports Server (NTRS)

    Fleming, David C.; Jones, Lisa (Technical Monitor)

    2002-01-01

    Crash modeling of composite structures remains limited in application and has not been effectively demonstrated as a predictive tool. While the global response of composite structures may be well modeled, when composite structures act as energy-absorbing members through direct laminate crushing the modeling accuracy is greatly reduced. The most efficient composite energy absorbing structures, in terms of energy absorbed per unit mass, are those that absorb energy through a complex progressive crushing response in which fiber and matrix fractures on a small scale dominate the behavior. Such failure modes simultaneously include delamination of plies, failure of the matrix to produce fiber bundles, and subsequent failure of fiber bundles either in bending or in shear. In addition, the response may include the significant action of friction, both internally (between delaminated plies or fiber bundles) or externally (between the laminate and the crushing surface). A figure shows the crushing damage observed in a fiberglass composite tube specimen, illustrating the complexity of the response. To achieve a finite element model of such complex behavior is an extremely challenging problem. A practical crushing model based on detailed modeling of the physical mechanisms of crushing behavior is not expected in the foreseeable future. The present research describes attempts to model composite crushing behavior using a novel hybrid modeling procedure. Experimental testing is done is support of the modeling efforts, and a test specimen is developed to provide data for validating laminate crushing models.

  18. Posttraumatic Growth After Motor Vehicle Crashes.

    PubMed

    Wu, Kitty K; Leung, Patrick W L; Cho, Valda W; Law, Lawrence S C

    2016-06-01

    The relationship between sub-dimensions of posttraumatic growth (PTG) and distress was investigated for survivors of motor vehicle crashes (MVC). PTG and symptoms of posttraumatic stress disorder (PTSD) for 1045 MVC survivors who attended the Accident and Emergency Services were examined with the Chinese versions of the Posttraumatic Growth Inventory (PTGI) and the Impact of Event Scale-Revised 1 week after the experience of a MVC. A factor structure, which was different from both the original English version of the PTGI and the Chinese version of PTGI for cancer survivors, was identified. Factors extracted were: (1) Life and Self Appreciation; (2) New Commitments; (3) Enlightenment; and (4) Relating to Others. However, correlation analyses indicated a functional similarity between factors from this study and those from previous studies. Relations between PTG sub-dimensions and PTSD symptoms were identified. Results from hierarchical multiple regression analysis and structural equation modeling show that there were different predictors for different PTG sub-dimensions. Findings suggest that different modes of relationship between PTSD symptoms and PTG sub-dimensions may co-exist. PMID:27040687

  19. Analysis of pregnant occupant crash exposure and the potential effectiveness of four-point seatbelts in far side crashes.

    PubMed

    Duma, Stefan M; Moorcroft, David M; Gabler, Hampton C; Manoogian, Sarah M; Stitzel, Joel D; Duma, Greg G

    2006-01-01

    The purpose of this paper is to present the crash exposure patterns of pregnant occupants and to evaluate the effectiveness of restraint systems, including four-point seatbelts, in far side crashes. The NASS CDS database revealed that 53.0 % of pregnant occupants are exposed to frontal crashes while 13.5 % are exposed to far side impacts. Given that far side crashes were the second leading crash mode after frontal impacts, a previously validated MADYMO computer model of a 30 week pregnant occupant was utilized to investigate pregnant occupant biomechanics in far side crashes. Three impact speeds (5, 15, and 25 mph) were simulated with four restraint conditions: unbelted, lap-belt only, three-point belt, and a four-point belt. Direct abdominal contact from the shoulder strap of the three-point or four-point belt caused uterine-placental strain in contrast to the inertial loading induced strain in the lap-belt and unbelted cases. Overall, the three-point and four-point belt systems provide superior restraint effectiveness for the pregnant occupant compared to the lap-belt and no restraint cases. The four-point resulted in slightly better performance than the three-point belt by reducing the fetal injury risk and occupant excursion.

  20. The Increased Risk of Road Crashes in Attention Deficit Hyperactivity Disorder (ADHD) Adult Drivers: Driven by Distraction? Results from a Responsibility Case-Control Study

    PubMed Central

    El Farouki, Kamal; Lagarde, Emmanuel; Orriols, Ludivine; Bouvard, Manuel-Pierre; Contrand, Benjamin; Galéra, Cédric

    2014-01-01

    Background and Objective Both distractions (external and internal) and attention-deficit/hyperactivity disorder (ADHD) are serious risk factors for traffic crashes and injuries. However, it is still unknown if ADHD (a chronic condition) modifies the effect of distractions (irregular hazards) on traffic crashes. The objective of this study was to assess the effects of distractions and ADHD on traffic crash responsibility. Methods A responsibility case-control study was conducted in the adult emergency department of Bordeaux University Hospital, France. Subjects were recruited among drivers injured in a motor vehicle crash between April 2010 and August 2011. Responsibility levels were estimated using a standardized method. Frequencies of exposures were compared between drivers responsible and drivers not responsible for the crash. Independent risk factors were identified using a multivariate logistic regression including test interactions between distractions and ADHD. Results A total of 777 subjects were included in the analysis. Factors associated with responsibility were distraction induced by an external event (adjusted OR (aOR)  = 1.47; 95% confidence interval (CI) [1.06–2.05]), distraction induced by an internal thought (aOR = 2.38; CI: [1.50–3.77]) and ADHD (aOR = 2.18 CI: [1.22–3.88]). The combined effect of ADHD and external distractions was strongly associated with responsibility for the crash (aOR = 5.79 CI: [2.06–16.32]). Interaction assessment showed that the attributable proportion due to the interaction among participants with both exposures was 68%. Discussion Adults with ADHD are a population at higher risk of being responsible for a road traffic crash when exposed to external distractions. This result reinforces the need to diagnose adult ADHD and to include road safety awareness messages delivered by the physician. Developing advanced driver assistance systems devoted to the management of attention lapses is also

  1. A crash-prediction model for road tunnels.

    PubMed

    Caliendo, Ciro; De Guglielmo, Maria Luisa; Guida, Maurizio

    2013-06-01

    Considerable research has been carried out into open roads to establish relationships between crashes and traffic flow, geometry of infrastructure and environmental factors, whereas crash-prediction models for road tunnels, have rarely been investigated. In addition different results have been sometimes obtained regarding the effects of traffic and geometry on crashes in road tunnels. However, most research has focused on tunnels where traffic and geometric conditions, as well as driving behaviour, differ from those in Italy. Thus, in this paper crash prediction-models that had not yet been proposed for Italian road tunnels have been developed. For the purpose, a 4-year monitoring period extending from 2006 to 2009 was considered. The tunnels investigated are single-tube ones with unidirectional traffic. The Bivariate Negative Binomial regression model, jointly applied to non-severe crashes (accidents involving material-damage only) and severe crashes (fatal and injury accidents only), was used to model the frequency of accident occurrence. The year effect on severe crashes was also analyzed by the Random Effects Binomial regression model and the Negative Multinomial regression model. Regression parameters were estimated by the Maximum Likelihood Method. The Cumulative Residual Method was used to test the adequacy of the regression model through the range of annual average daily traffic per lane. The candidate set of variables was: tunnel length (L), annual average daily traffic per lane (AADTL), percentage of trucks (%Tr), number of lanes (NL), and the presence of a sidewalk. Both for non-severe crashes and severe crashes, prediction-models showed that significant variables are: L, AADTL, %Tr, and NL. A significant year effect consisting in a systematic reduction of severe crashes over time was also detected. The analysis developed in this paper appears to be useful for many applications such as the estimation of accident reductions due to improvement in existing

  2. Avoiding Statistical Mistakes

    ERIC Educational Resources Information Center

    Strasser, Nora

    2007-01-01

    Avoiding statistical mistakes is important for educators at all levels. Basic concepts will help you to avoid making mistakes using statistics and to look at data with a critical eye. Statistical data is used at educational institutions for many purposes. It can be used to support budget requests, changes in educational philosophy, changes to…

  3. Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials

    PubMed Central

    2011-01-01

    Background All sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made. Methods We conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials), quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared. Results The total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions), whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions). Conclusions Faster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1. Trial Registration Numbers CRASH-1: ISRCTN74459797 CRASH-2: ISRCTN86750102 PMID:21291517

  4. Spatial regression analysis of traffic crashes in Seoul.

    PubMed

    Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

    2016-06-01

    Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. PMID:26994374

  5. A Reexamination of the Small Overlap Frontal Crash

    PubMed Central

    Scullion, Paul; Morgan, Richard M.; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 – 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 – 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study—following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC—suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  6. Methodology to develop crash modification functions for road safety treatments with fully specified and hierarchical models.

    PubMed

    Chen, Yongsheng; Persaud, Bhagwant

    2014-09-01

    Crash modification factors (CMFs) for road safety treatments are developed as multiplicative factors that are used to reflect the expected changes in safety performance associated with changes in highway design and/or the traffic control features. However, current CMFs have methodological drawbacks. For example, variability with application circumstance is not well understood, and, as important, correlation is not addressed when several CMFs are applied multiplicatively. These issues can be addressed by developing safety performance functions (SPFs) with components of crash modification functions (CM-Functions), an approach that includes all CMF related variables, along with others, while capturing quantitative and other effects of factors and accounting for cross-factor correlations. CM-Functions can capture the safety impact of factors through a continuous and quantitative approach, avoiding the problematic categorical analysis that is often used to capture CMF variability. There are two formulations to develop such SPFs with CM-Function components - fully specified models and hierarchical models. Based on sample datasets from two Canadian cities, both approaches are investigated in this paper. While both model formulations yielded promising results and reasonable CM-Functions, the hierarchical model was found to be more suitable in retaining homogeneity of first-level SPFs, while addressing CM-Functions in sub-level modeling. In addition, hierarchical models better capture the correlations between different impact factors.

  7. Highway crash rates and age-related driver limitations: Literature review and evaluation of data bases

    SciTech Connect

    Hu, P.S.; Young, J.R.; Lu, An

    1993-08-01

    American society is undergoing a major demographic transformation that is resulting in a larger proportion of older individuals in the population. Moreover, recent travel surveys show that an increasing number of older individuals are licensed to drive and that they drive more than their same age cohort a decade ago. However, they continue to take shorter trips than younger drivers and they avoid driving during congested hours. This recent demographic transformation in our society, the graying of America, coupled with the increasing mobility of the older population impose a serious highway safety issue that cannot be overlooked. Some of the major concerns are the identification of ``high-risk`` older drivers and the establishment of licensing guidelines and procedures that are based on conclusive scientific evidence. Oak Ridge National Laboratory`s (ORNL) objectives in this project can be characterized by the following tasks: Review and evaluate the 1980 American Association of Motor Vehicle Administrators (AAMVA) and National Highway Traffic Safety Administration (NHTSA) licensing guidelines. Determine whether the license restriction recommended in the 1980 AAMVA and NHTSA guidelines was based on scientific evidence or on judgement of medical advisors. Identify in the scientific literature any medical conditions which are found to be highly associated with highway crashes, and which are not mentioned in the 1980 guidelines. Summarize States` current licensing practices for drivers with age-related physical and mental limitations. Identify potential data sources to establish conclusive evidence on age-related functional impairments and highway crashes.

  8. A method for evaluating collision avoidance systems using naturalistic driving data.

    PubMed

    McLaughlin, Shane B; Hankey, Jonathan M; Dingus, Thomas A

    2008-01-01

    This paper describes a method for use in evaluating the performance of collision avoidance systems (CASs) using naturalistic driving data collected during real crashes and near-crashes. The method avoids evaluation of algorithms against specific assumptions of reaction times or response inputs. It minimizes interpretation of the involved driver's perception and response levels which permits generalizing findings beyond the performance of the involved driver. The method involves four parts: input of naturalistic crash data into alert models to determine when alerts would occur, kinematic analysis to determine when different responses would be required to avoid collision, translation of the time available into an estimate of the percentage of the population able to avoid the specific event, and an evaluation of the frequency of alerts that would be generated by the CASs. The method permits comparison of CAS performance and provides guidance for CAS development. The method is described primarily in the context of Forward Collision Warning CASs, but is applicable to other CAS types.

  9. Delamination Modeling of Composites for Improved Crash Analysis

    NASA Technical Reports Server (NTRS)

    Fleming, David C.

    1999-01-01

    Finite element crash modeling of composite structures is limited by the inability of current commercial crash codes to accurately model delamination growth. Efforts are made to implement and assess delamination modeling techniques using a current finite element crash code, MSC/DYTRAN. Three methods are evaluated, including a straightforward method based on monitoring forces in elements or constraints representing an interface; a cohesive fracture model proposed in the literature; and the virtual crack closure technique commonly used in fracture mechanics. Results are compared with dynamic double cantilever beam test data from the literature. Examples show that it is possible to accurately model delamination propagation in this case. However, the computational demands required for accurate solution are great and reliable property data may not be available to support general crash modeling efforts. Additional examples are modeled including an impact-loaded beam, damage initiation in laminated crushing specimens, and a scaled aircraft subfloor structures in which composite sandwich structures are used as energy-absorbing elements. These examples illustrate some of the difficulties in modeling delamination as part of a finite element crash analysis.

  10. Urban sprawl as a risk factor in motor vehicle crashes

    USGS Publications Warehouse

    Ewing, Reid; Hamidi, Shima; Grace, James B.

    2016-01-01

    A decade ago, compactness/sprawl indices were developed for metropolitan areas and counties which have been widely used in health and other research. In this study, we first update the original county index to 2010, then develop a refined index that accounts for more relevant factors, and finally seek to test the relationship between sprawl and traffic crash rates using structural equation modelling. Controlling for covariates, we find that sprawl is associated with significantly higher direct and indirect effects on fatal crash rates. The direct effect is likely due to the higher traffic speeds in sprawling areas, and the indirect effect is due to greater vehicle miles driven in such areas. Conversely, sprawl has negative direct relationships with total crashes and non-fatal injury crashes, and these offset (and sometimes overwhelm) the positive indirect effects of sprawl on both types of crashes through the mediating effect of increased vehicle miles driven. The most likely explanation is the greater prevalence of fender benders and other minor accidents in the low speed, high conflict traffic environments of compact areas, negating the lower vehicle miles travelled per capita in such areas.

  11. Avoiding Computer Viruses.

    ERIC Educational Resources Information Center

    Rowe, Joyce; And Others

    1989-01-01

    The threat of computer sabotage is a real concern to business teachers and others responsible for academic computer facilities. Teachers can minimize the possibility. Eight suggestions for avoiding computer viruses are given. (JOW)

  12. Avoiding Construction Snafus.

    ERIC Educational Resources Information Center

    Rochefort, Mark; Gosch, Jerry

    2001-01-01

    Discusses risk management planning tips that help schools avoid project-delaying construction problems. Preconstruction planning topics explored include the type of construction method to use, contract selection, and the need for efficient project management. (GR)

  13. Identify sequence of events likely to result in severe crash outcomes.

    PubMed

    Wu, Kun-Feng; Thor, Craig P; Ardiansyah, Muhammad Nashir

    2016-11-01

    The current practice of crash characterization in highway engineering reduces multiple dimensions of crash contributing factors and their relative sequential connections, crash sequences, into broad definitions, resulting in crash categories such as head-on, sideswipe, rear-end, angle, and fixed-object. As a result, crashes that are classified in the same category may contain many different crash sequences. This makes it difficult to develop effective countermeasures because these crash categorizations are based on the outcomes rather than the preceding events. Consequently, the efficacy of a countermeasure designed for a specific type of crash may not be appropriate due to different pre-crash sequences. This research seeks to explore the use of event sequence to characterize crashes. Additionally, this research seeks to identify crash sequences that are likely to result in severe crash outcomes so that researchers can develop effective countermeasures to reduce severe crashes. This study utilizes the sequence of events from roadway departure crashes in the Fatality Analysis Reporting System (FARS), and converts the information to form a new categorization called "crash sequences." The similarity distance between each pair of crash sequences were calculated using the Optimal Matching approach. Cluster analysis was applied to group crash sequences that are etiologically similar in terms of the similarity distance. A hybrid model was constructed to mitigate the potential sample selection bias of FARS data, which is biased toward more severe crashes. The major findings include: (1) in terms of a roadway departure crash, the crash sequences that are most likely to result in high crash severity include a vehicle that first crosses the median or centerline, runs-off-road on the left, and then collides with a roadside fixed-object; (2) seat-belt and airbag usage reduces the probability of dying in a roadway departure crash by 90%; and (3) occupants who are seated on the

  14. Identify sequence of events likely to result in severe crash outcomes.

    PubMed

    Wu, Kun-Feng; Thor, Craig P; Ardiansyah, Muhammad Nashir

    2016-11-01

    The current practice of crash characterization in highway engineering reduces multiple dimensions of crash contributing factors and their relative sequential connections, crash sequences, into broad definitions, resulting in crash categories such as head-on, sideswipe, rear-end, angle, and fixed-object. As a result, crashes that are classified in the same category may contain many different crash sequences. This makes it difficult to develop effective countermeasures because these crash categorizations are based on the outcomes rather than the preceding events. Consequently, the efficacy of a countermeasure designed for a specific type of crash may not be appropriate due to different pre-crash sequences. This research seeks to explore the use of event sequence to characterize crashes. Additionally, this research seeks to identify crash sequences that are likely to result in severe crash outcomes so that researchers can develop effective countermeasures to reduce severe crashes. This study utilizes the sequence of events from roadway departure crashes in the Fatality Analysis Reporting System (FARS), and converts the information to form a new categorization called "crash sequences." The similarity distance between each pair of crash sequences were calculated using the Optimal Matching approach. Cluster analysis was applied to group crash sequences that are etiologically similar in terms of the similarity distance. A hybrid model was constructed to mitigate the potential sample selection bias of FARS data, which is biased toward more severe crashes. The major findings include: (1) in terms of a roadway departure crash, the crash sequences that are most likely to result in high crash severity include a vehicle that first crosses the median or centerline, runs-off-road on the left, and then collides with a roadside fixed-object; (2) seat-belt and airbag usage reduces the probability of dying in a roadway departure crash by 90%; and (3) occupants who are seated on the

  15. Avoiding the SCAMs.

    PubMed

    Kidd, Thomas; Condron, Barry

    2007-05-01

    Dendrites from the same neuron usually avoid contact with one another, a behavior known as self-avoidance. In this issue of Neuron and in the upcoming May 4, 2007 issue of Cell, a pair of studies by Soba et al. and Hughes et al. and a study by Matthews et al., respectively, identify products from the highly alternatively spliced Dscam gene as central to this behavior in Drosophila. Signaling induced by adhesion between identical isoforms triggers repulsion between sister dendrites.

  16. Avoided Crossing and Synchronization

    NASA Astrophysics Data System (ADS)

    Sekii, T.; Shibahashi, H.

    2013-12-01

    We examine avoided crossing of stellar pulsations in the nonlinear regime, where synchronization may occur, based on a simple model of weakly coupled van der Pol oscillators with close frequencies. For this simple case, avoided crossing is unaffected in the sense that there is a frequency difference between the symmetric and antisymmetric modes, but as a result of synchronization, unlike the linear oscillations case, the system can vibrate in only one of the modes.

  17. Operational Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Guit, Bill

    2015-01-01

    This presentation will describe the early days of the EOS Aqua and Aura operational collision avoidance process. It will highlight EOS debris avoidance maneuvers, EOS high interest event statistic and A-Train systematic conjunctions and conclude with future challenges. This is related to earlier e-DAA (tracking number 21692) that an abstract was submitted to a different conference. Eric Moyer, ESMO Deputy Project Manager has reviewed and approved this presentation on May 6, 2015

  18. CRASH-2 Study of Tranexamic Acid to Treat Bleeding in Trauma Patients: A Controversy Fueled by Science and Social Media

    PubMed Central

    Binz, Sophia; McCollester, Jonathon; Thomas, Scott; Miller, Joseph; Pohlman, Timothy; Waxman, Dan; Shariff, Faisal; Tracy, Rebecca; Walsh, Mark

    2015-01-01

    This paper reviews the application of tranexamic acid, an antifibrinolytic, to trauma. CRASH-2, a large randomized controlled trial, was the first to show a reduction in mortality and recommend tranexamic acid use in bleeding trauma patients. However, this paper was not without controversy. Its patient recruitment, methodology, and conductance in moderate-to-low income countries cast doubt on its ability to be applied to trauma protocols in countries with mature trauma networks. In addition to traditional vetting in scientific, peer-reviewed journals, CRASH-2 came about at a time when advances in communication technology allowed debate and influence to be leveraged in new forms, specifically through the use of multimedia campaigns, social media, and Internet blogs. This paper presents a comprehensive view of tranexamic acid utilization in trauma from peer-reviewed evidence to novel multimedia influences. PMID:26448897

  19. CRASH-2 Study of Tranexamic Acid to Treat Bleeding in Trauma Patients: A Controversy Fueled by Science and Social Media.

    PubMed

    Binz, Sophia; McCollester, Jonathon; Thomas, Scott; Miller, Joseph; Pohlman, Timothy; Waxman, Dan; Shariff, Faisal; Tracy, Rebecca; Walsh, Mark

    2015-01-01

    This paper reviews the application of tranexamic acid, an antifibrinolytic, to trauma. CRASH-2, a large randomized controlled trial, was the first to show a reduction in mortality and recommend tranexamic acid use in bleeding trauma patients. However, this paper was not without controversy. Its patient recruitment, methodology, and conductance in moderate-to-low income countries cast doubt on its ability to be applied to trauma protocols in countries with mature trauma networks. In addition to traditional vetting in scientific, peer-reviewed journals, CRASH-2 came about at a time when advances in communication technology allowed debate and influence to be leveraged in new forms, specifically through the use of multimedia campaigns, social media, and Internet blogs. This paper presents a comprehensive view of tranexamic acid utilization in trauma from peer-reviewed evidence to novel multimedia influences. PMID:26448897

  20. Impact and Injury Patterns in Between-Rails Frontal Crashes of Vehicles with Good Ratings for Frontal Crash Protection

    PubMed Central

    Morgan, Richard M.; Cui, Chongzhen; Digges, Kennerly H.; Cao, Libo; Kan, Cing-Dao (Steve)

    2012-01-01

    This research investigated (1) what are the key attributes of the between-rail, frontal crash, (2) what are the types of object contacted, and (3) what is the type of resulting trauma. The method was to study with both weighted and in-depth case reviews of NASS-CDS crash data with direct damage between the longitudinal rails in frontal crashes. Individual case selection was limited to belted occupants in between-rail, frontal impacts of good-rated, late-model vehicles equipped with air bags. This paper evaluates the risk of trauma for drivers in cars and LTVs in between-rail, frontal crashes, and suggests the between-rail impact is more dangerous to car drivers. Using weighted data—representing 227,305 tow-away crashes—the resulting trauma to various body regions was analyzed to suggest greatest injury is to the chest, pelvis/thigh/knee/leg, and foot/ankle. This study analyzed the type of object that caused the direct damage between the rails, including small tree or post, large tree or pole, and another vehicle; and found that the struck object was most often another vehicle or a large tree/pole. Both the extent of damage and the occupant compartment intrusion were explored, and suggest that 64% of the serious injuries are associated with increasing intrusion. Individual NASS cases were reviewed to gain a deeper understanding of the mechanical particulars in the between-rail crash. PMID:23169135

  1. Chain-reaction crash on a highway in high visibility

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2016-05-01

    We study the chain-reaction crash (multiple-vehicle collision) in high-visibility condition on a highway. In the traffic situation, drivers control their vehicles by both gear-changing and braking. Drivers change the gears according to the headway and brake according to taillights of the forward vehicle. We investigate whether or not the first collision induces the chain-reaction crash numerically. It is shown that dynamic transitions occur from no collisions, through a single collision, to multiple collisions with decreasing the headway. Also, we find that the dynamic transition occurs from the finite chain reaction to the infinite chain reaction when the headway is less than the critical value. We compare the multiple-vehicle collisions in high-visibility with that in low-visibility. We derive the transition points and the region maps for the chain-reaction crash in high visibility.

  2. Evaluation of Test/Analysis Correlation Methods for Crash Applications

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Bark, Lindley W.; Jackson, Karen E.

    2001-01-01

    A project has been initiated to improve crash test and analysis correlation. The work in this paper concentrated on the test and simulation results for a fuselage section. Two drop tests of the section were conducted. The first test was designed to excite the linear structural response for comparison with finite element modal analysis results. The second test was designed to provide data for correlation with crash simulations. An MSC.Dytran model was developed to generate nonlinear transient dynamic results. Following minor modifications, the same model was executed in MSC.Nastran to generate modal analysis results. The results presented in this paper concentrate on evaluation of correlation methodologies for crash test data and finite element simulation results.

  3. General aviation crash safety program at Langley Research Center

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.

    1976-01-01

    The purpose of the crash safety program is to support development of the technology to define and demonstrate new structural concepts for improved crash safety and occupant survivability in general aviation aircraft. The program involves three basic areas of research: full-scale crash simulation testing, nonlinear structural analyses necessary to predict failure modes and collapse mechanisms of the vehicle, and evaluation of energy absorption concepts for specific component design. Both analytical and experimental methods are being used to develop expertise in these areas. Analyses include both simplified procedures for estimating energy absorption capabilities and more complex computer programs for analysis of general airframe response. Full-scale tests of typical structures as well as tests on structural components are being used to verify the analyses and to demonstrate improved design concepts.

  4. Developmental sources of crash risk in young drivers

    PubMed Central

    Arnett, J; Irwin, C; Halpern-Felsher, B

    2002-01-01

    Methods and Results: First, a distinction is made between adolescence (ages 10–18) and emerging adulthood (ages 18–25) in order to shed light on the reasons for especially high crash rates among 16–17 year old drivers relative to 18–25 year olds. Then various developmental sources of risk in adolescence are described, including the power of friends, the optimistic bias, and adolescent emotionality. The reasons for especially high crash rates among young males are discussed, with an emphasis on how American ideas about manhood promote driving risks. Finally, a cross national comparison between adolescents in the United States and Denmark shows how developmental risks interact with driving policies. Conclusions: The high crash rates of adolescents relative to emerging adults and of emerging adults relative to older drivers can be explained in part by developmental factors. PMID:12221026

  5. Origin and Prevention of Crash Fires in Turbojet Aircraft

    NASA Technical Reports Server (NTRS)

    Pinkel, I. Irvin; Weiss, Solomon; Preston, G. Merritt; Pesman, Gerard J.

    1958-01-01

    The tendency for the jet engine rotor to continue to rotate after crash presents the probability that crash-spilled combustibles suspended in the air or puddled on the ground at the engine inlet may be sucked into the engine. Studies with jet engines operating on a test stand and full-scale crashes of turbojet-powered airplanes showed that combustibles drawn into the engine in this way ignite explosively within the engine. Experiment showed that the gas flow through the engine is too rapid to permit the ignition of ingested combustibles on the hot metal in contact with the main gas stream. Ignition will occur on those hot surfaces not in the main gas stream. The portion of the engine airflow is diverted for cooling and ventilation to these zones where the gas moves slowly enough for ignition to occur.

  6. NASA/FAA general aviation crash dynamics program

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Hayduk, R. J.; Carden, H. D.

    1981-01-01

    The program involves controlled full scale crash testing, nonlinear structural analyses to predict large deflection elastoplastic response, and load attenuating concepts for use in improved seat and subfloor structure. Both analytical and experimental methods are used to develop expertise in these areas. Analyses include simplified procedures for estimating energy dissipating capabilities and comprehensive computerized procedures for predicting airframe response. These analyses are developed to provide designers with methods for predicting accelerations, loads, and displacements on collapsing structure. Tests on typical full scale aircraft and on full and subscale structural components are performed to verify the analyses and to demonstrate load attenuating concepts. A special apparatus was built to test emergency locator transmitters when attached to representative aircraft structure. The apparatus is shown to provide a good simulation of the longitudinal crash pulse observed in full scale aircraft crash tests.

  7. Aircraft-mounted crash-activated transmitter device

    NASA Technical Reports Server (NTRS)

    Manoli, R.; Ulrich, B. R. (Inventor)

    1976-01-01

    An aircraft crash location transmitter tuned to transmit on standard emergency frequencies is reported that is shock mounted in a sealed circular case atop the tail of an aircraft by means of a shear pin designed to fail under a G loading associated with a crash situation. The antenna for the transmitter is a metallic spring blade coiled like a spiral spring around the outside of the circular case. A battery within the case for powering the transmitter is kept trickle charged from the electrical system of the aircraft through a break away connector on the case. When a crash occurs, the resultant ejection of the case from the tail due to a failure of the shear pin releases the free end of the antenna which automatically uncoils. The accompanying separation of the connector effects closing of the transmitter key and results in commencement of transmission.

  8. Option pricing during post-crash relaxation times

    NASA Astrophysics Data System (ADS)

    Dibeh, Ghassan; Harmanani, Haidar M.

    2007-07-01

    This paper presents a model for option pricing in markets that experience financial crashes. The stochastic differential equation (SDE) of stock price dynamics is coupled to a post-crash market index. The resultant SDE is shown to have stock price and time dependent volatility. The partial differential equation (PDE) for call prices is derived using risk-neutral pricing. European call prices are then estimated using Monte Carlo and finite difference methods. Results of the model show that call option prices after the crash are systematically less than those predicted by the Black-Scholes model. This is a result of the effect of non-constant volatility of the model that causes a volatility skew.

  9. Increased risk of driver fatality due to unrestrained rear-seat passengers in severe frontal crashes.

    PubMed

    Bose, Dipan; Arregui-Dalmases, Carlos; Sanchez-Molina, David; Velazquez-Ameijide, Juan; Crandall, Jeff

    2013-04-01

    While belt usage among rear-seat passengers is disproportionately lower than their front-seat counterpart, this may have serious consequences in the event of a crash not only for the unbelted rear-seat passenger but also for the front-seat passengers as well. To quantify that effect, the objective of the study is to evaluate the increased likelihood of driver fatality in the presence of unrestrained rear-seat passengers in a severe frontal collision. U.S.-based census data from 2001 to 2009 fatal motor vehicle crashes was used to enroll frontal crashes which involved 1998 or later year vehicle models with belted drivers and at least one adult passenger in the rear left seat behind the driver. Results using multivariate logistic regression analysis indicated that the odds of a belt restrained driver sustaining a fatal injury was 137% (95% CI=95%, 189%) higher when the passenger behind the driver was unbelted in comparison to a belted case while the effects of driver age, sex, speed limit, vehicle body type, airbag deployment and driver ejection were controlled in the model. The likelihood of driver fatality due to an unrestrained rear left passenger increased further (119-197%) in the presence of additional unrestrained rear seat passengers in the rear middle or right seats. The results from the study highlight the fact that future advances to front row passive safety systems (e.g. multi-stage airbag deployment) must be adapted to take into account the effect of unrestrained rear-seat passengers. PMID:23411155

  10. Fatal motor vehicle crashes in rural and urban areas: decomposing rates into contributing factors

    PubMed Central

    Zwerling, C; Peek-Asa, C; Whitten, P; Choi, S; Sprince, N; Jones, M

    2005-01-01

    Objectives: Motor vehicle crash fatality rates have been consistently higher in rural areas than in urban areas. However, the explanations for these differences are less clear. In this study the decomposition method was used to explore the factors associated with increased fatal crash involvement rates in rural communities. Design: Using national databases, the fatal crash incidence density was decomposed into the product of three factors: the injury fatality rate, the crash injury rate, and the crash incidence density. Results: As expected, the fatal crash incidence density was more than two times higher in rural than in urban areas. This was driven primarily by the injury fatality rate, which was almost three times higher in rural areas. Conclusions: Further research should examine the relative roles of crash severity and the timely receipt of definitive medical care after a crash. PMID:15691985

  11. U.S. Car Crash Deaths Down, but Still Surpass Other Nations

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159736.html U.S. Car Crash Deaths Down, But Still Surpass Other Nations ... 6, 2016 WEDNESDAY, July 6, 2016 (HealthDay News) -- Car crash deaths on American roads fell nearly one- ...

  12. Deaths from international terrorism compared with road crash deaths in OECD countries

    PubMed Central

    Wilson, N; Thomson, G

    2005-01-01

    Methods: Data on deaths from international terrorism (US State Department database) were collated (1994–2003) and compared to the road injury deaths (year 2000 and 2001 data) from the OECD International Road Transport Accident Database. Results: In the 29 OECD countries for which comparable data were available, the annual average death rate from road injury was approximately 390 times that from international terrorism. The ratio of annual road to international terrorism deaths (averaged over 10 years) was lowest for the United States at 142 times. In 2001, road crash deaths in the US were equal to those from a September 11 attack every 26 days. Conclusions: There is a large difference in the magnitude of these two causes of deaths from injury. Policy makers need to be aware of this when allocating resources to preventing these two avoidable causes of mortality. PMID:16326764

  13. Preliminary study of the application of synthetic vision for obstacle avoidance on highways

    NASA Astrophysics Data System (ADS)

    Misener, James A.; Sengupta, Raja; Godbole, Datta N.

    1997-06-01

    Understanding and characterizing the forward environment of a ground vehicle is a pivotal element in determining the appropriate maneuver-response strategy while under varied degrees of vehicle automation. Potential degrees of automation span the probable near-term adoption of longitudinal crash countermeasure warning devices all the way through the longer-term objective of full vehicle automation. Between these extremes lies partially automated longitudinal crash avoidance, a potentially rich area of application for synthetic vision. This paper addresses the application of synthetic vision to vehicle automation from a systems perspective: from development of a collision avoidance framework, to application of the appropriate sensor-environmental descriptions with which synthetic vision applications can address. Obstacle detection modules, the human cognitive component and the dynamics of automated ground vehicle control comprise elements of this framework. Areas to fulfill a structured program and suggested areas for further in-depth research are identified.

  14. A fuzzy logic approach to modeling a vehicle crash test

    NASA Astrophysics Data System (ADS)

    Pawlus, Witold; Karimi, Hamid; Robbersmyr, Kjell

    2013-03-01

    This paper presents an application of fuzzy approach to vehicle crash modeling. A typical vehicle to pole collision is described and kinematics of a car involved in this type of crash event is thoroughly characterized. The basics of fuzzy set theory and modeling principles based on fuzzy logic approach are presented. In particular, exceptional attention is paid to explain the methodology of creation of a fuzzy model of a vehicle collision. Furthermore, the simulation results are presented and compared to the original vehicle's kinematics. It is concluded which factors have influence on the accuracy of the fuzzy model's output and how they can be adjusted to improve the model's fidelity.

  15. Reactive Collision Avoidance Algorithm

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on

  16. The relative contribution of system failures and extreme behaviour in South Australian crashes.

    PubMed

    Wundersitz, Lisa; Baldock, Matthew; Raftery, Simon

    2014-12-01

    Within the road system, there are compliant road users who may make an error that leads to a crash, resulting in a 'system failure', and there are also road users who deliberately take risks and display dangerous or 'extreme' behaviours that lead to a crash. Crashes resulting from system failures can be addressed through improvements to road system design more readily than crashes resulting from extreme behaviours. The classification of crash causation in terms of system failures or extreme behaviour is important for determining the extent to which a Safe System approach (i.e. improvements to road system design to serve compliant road users) is capable of reducing the number of crashes. This study examined the relative contribution of system failures and extreme behaviour in South Australian crashes as identified from information in Coroner's investigation files and in-depth crash investigations conducted by the Centre for Automotive Safety Research (CASR). The analysis of 189 fatal crashes, 272 non-fatal metropolitan injury crashes and 181 non-fatal rural crashes indicated that very few non-fatal crashes (3% metropolitan, 9% rural) involved extreme behaviour by road users and, even in fatal crashes, the majority (54%) were the result of system failures. Fatal crashes resulting from system failures were more likely than those resulting from extreme behaviour to occur during the day, on weekdays, in rural areas and on roads with high speed limits. Findings from the current study suggest that improvements to the road transport system (i.e. forgiving road infrastructure, appropriate speed limits, and safe vehicle design) can be expected to be much more effective in reducing crashes than concentrating on preventing extreme behaviours. Such a strategy could reduce the incidence and severity of a large proportion of crashes in South Australia. PMID:25238295

  17. The relative contribution of system failures and extreme behaviour in South Australian crashes.

    PubMed

    Wundersitz, Lisa; Baldock, Matthew; Raftery, Simon

    2014-12-01

    Within the road system, there are compliant road users who may make an error that leads to a crash, resulting in a 'system failure', and there are also road users who deliberately take risks and display dangerous or 'extreme' behaviours that lead to a crash. Crashes resulting from system failures can be addressed through improvements to road system design more readily than crashes resulting from extreme behaviours. The classification of crash causation in terms of system failures or extreme behaviour is important for determining the extent to which a Safe System approach (i.e. improvements to road system design to serve compliant road users) is capable of reducing the number of crashes. This study examined the relative contribution of system failures and extreme behaviour in South Australian crashes as identified from information in Coroner's investigation files and in-depth crash investigations conducted by the Centre for Automotive Safety Research (CASR). The analysis of 189 fatal crashes, 272 non-fatal metropolitan injury crashes and 181 non-fatal rural crashes indicated that very few non-fatal crashes (3% metropolitan, 9% rural) involved extreme behaviour by road users and, even in fatal crashes, the majority (54%) were the result of system failures. Fatal crashes resulting from system failures were more likely than those resulting from extreme behaviour to occur during the day, on weekdays, in rural areas and on roads with high speed limits. Findings from the current study suggest that improvements to the road transport system (i.e. forgiving road infrastructure, appropriate speed limits, and safe vehicle design) can be expected to be much more effective in reducing crashes than concentrating on preventing extreme behaviours. Such a strategy could reduce the incidence and severity of a large proportion of crashes in South Australia.

  18. Collision Avoidance System

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Ames Research Center teamed with the Federal Aviation Administration (FAA) to study human performance factors associated with the use of the Traffic Alert and Collision Avoidance system (TCAS II) in an operational environment. TCAS is designed to alert pilots of the presence of other aircraft in their vicinity, to identify and track those who could be a threat, and to recommend action to avoid a collision. Ames conducted three laboratory experiments. The first showed that pilots were able to use the TCAS II correctly in the allowable time. The second tested pilots' response to changes in the avoidance advisories, and the third examined pilots' reactions to alternative displays. After a 1989 congressional mandate, the FAA ruled that TCAS would be required on all passenger carrying aircraft (to be phased in completely by 1995).

  19. Characteristics of Crashes with Farm Equipment that Increase Potential for Injury

    ERIC Educational Resources Information Center

    Peek-Asa, Corinne; Sprince, Nancy L.; Whitten, Paul S.; Falb, Scott R.; Madsen, Murray D.; Zwerling, Craig

    2007-01-01

    Context: Crash fatality and injury rates are higher on rural roadways than other roadway types. Although slow-moving farm vehicles and equipment are risk factors on rural roads, little is known about the characteristics of crashes with farm vehicles/equipment. Purpose: To describe crashes and injuries for the drivers of farm vehicles/equipment and…

  20. Prevalence and factors associated with road traffic crash among bus drivers in Hanoi, Vietnam.

    PubMed

    La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

    2013-01-01

    Bus provides a main mode of public transport in Vietnam, but the risk of road traffic crash for bus drivers is unknown. This retrospective study estimated the crash prevalence among bus drivers in Hanoi, Vietnam, and identified driver characteristics affecting their crashes. Information on bus crashes for the period 2006-2009 was collected by interviewing drivers from five bus companies in Hanoi using a structured questionnaire. Logistic regression analysis was performed to determine pertinent risk factors affecting the crash prevalence for bus drivers. Of the total 365 participants recruited, 73 drivers reported 76 crashes, giving an overall crash prevalence of 20%. Among the crashed group, three drivers (4%) were involved in two crashes during the past 3 years. Crashes mainly occurred on streets or local roads (81%). Migrant worker (adjusted odds ratio (OR) 4.26, 95% confidence interval (CI) 2.20-8.25) and insufficient income perceived (OR 2.60, 95% CI 1.37-4.93) were identified to be significantly associated with the crash risk. Further prospective and qualitative studies are needed to provide detailed crash characteristics as well as behaviour and perception of bus drivers, so that an effective intervention can be developed to improve road safety and to prevent traffic injury of these drivers.

  1. Investigation of pedestrian crashes on two-way two-lane rural roads in Ethiopia.

    PubMed

    Tulu, Getu Segni; Washington, Simon; Haque, Md Mazharul; King, Mark J

    2015-05-01

    Understanding pedestrian crash causes and contributing factors in developing countries is critically important as they account for about 55% of all traffic crashes. Not surprisingly, considerable attention in the literature has been paid to road traffic crash prediction models and methodologies in developing countries of late. Despite this interest, there are significant challenges confronting safety managers in developing countries. For example, in spite of the prominence of pedestrian crashes occurring on two-way two-lane rural roads, it has proven difficult to develop pedestrian crash prediction models due to a lack of both traffic and pedestrian exposure data. This general lack of available data has further hampered identification of pedestrian crash causes and subsequent estimation of pedestrian safety performance functions. The challenges are similar across developing nations, where little is known about the relationship between pedestrian crashes, traffic flow, and road environment variables on rural two-way roads, and where unique predictor variables may be needed to capture the unique crash risk circumstances. This paper describes pedestrian crash safety performance functions for two-way two-lane rural roads in Ethiopia as a function of traffic flow, pedestrian flows, and road geometry characteristics. In particular, random parameter negative binomial model was used to investigate pedestrian crashes. The models and their interpretations make important contributions to road crash analysis and prevention in developing countries. They also assist in the identification of the contributing factors to pedestrian crashes, with the intent to identify potential design and operational improvements.

  2. Crash and Risky Driving Involvement Among Novice Adolescent Drivers and Their Parents

    PubMed Central

    Ouimet, Marie Claude; Zhang, Zhiwei; Klauer, Sheila E.; Lee, Suzanne E.; Wang, Jing; Albert, Paul S.; Dingus, Thomas A.

    2011-01-01

    Objectives. We compared rates of risky driving among novice adolescent and adult drivers over the first 18 months of adolescents' licensure. Methods. Data-recording systems installed in participants’ vehicles provided information on driving performance of 42 newly licensed adolescent drivers and their parents. We analyzed crashes and near crashes and elevated g-force event rates by Poisson regression with random effects. Results. During the study period, adolescents were involved in 279 crashes or near crashes (1 involving injury); parents had 34 such accidents. The incidence rate ratio (IRR) comparing adolescent and parent crash and near-crash rates was 3.91. Among adolescent drivers, elevated rates of g-force events correlated with crashes and near crashes (r = 0.60; P < .001). The IRR comparing incident rates of risky driving among adolescents and parents was 5.08. Adolescents’ rates of crashes and near crashes declined with time (with a significant uptick in the last quarter), but elevated g-force event rates did not decline. Conclusions. Elevated g-force events among adolescents may have contributed to crash and near-crash rates that remained much higher than adult levels after 18 months of driving. PMID:22021319

  3. Avoiding the "M" Word.

    ERIC Educational Resources Information Center

    Klinger, Donna

    2001-01-01

    Provides an overview of roundtable discussions by top business officers about how higher education can capitalize on strategic alliances. Describes how, by working with one another and with corporate partners, colleges and universities can avoid closing their doors or merging with stronger institutions. (EV)

  4. Psychological Treatments to Avoid

    ERIC Educational Resources Information Center

    Thomason, Timothy C.

    2010-01-01

    Certain psychological treatments should be avoided, and a list of such treatments would provide valuable guidance for counselors, as well as potential clients. It is well established that some therapies are potentially dangerous, and some fringe therapies are highly unlikely to help clients beyond a placebo effect. This article provides an…

  5. Myelin Avoids the JAM.

    PubMed

    Follis, Rose M; Carter, Bruce D

    2016-08-17

    In this issue of Neuron, Redmond et al. (2016) identify junction adhesion molecule 2 (JAM2) as an inhibitor of somatodendritic myelination in spinal cord neurons, thereby elucidating how myelin forms on axons but avoids dendrites and cell bodies. PMID:27537479

  6. Plants to Avoid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of poisonous plants is extremely important for home owners, gardeners, farmers, hunters, hikers, and the rest of the general public. Among the most important plants to avoid in the Delta Region are poison ivy, bull nettle, eastern black nightshade, Queen Ann’s lace, jimsonweed, and trumpe...

  7. Socioeconomic aspects of the circumstances and consequences of car crashes among young adults.

    PubMed

    Hasselberg, Marie; Vaez, Marjan; Laflamme, Lucie

    2005-01-01

    The study examines whether there are socioeconomic differences between young adult car drivers involved in road-traffic crashes with regard to crash-injury severity and crash circumstances. Differences in social patterning based on socioeconomic position (SEP) of origin and of destination, and also the effect of gender, are considered. Subjects born in 1970-1972 were extracted from the Swedish Population and Housing Census of 1985 (n = 329,716). Individual records from the 1985 census were linked to road-traffic data for the period 1988-2000 on the basis of a search for each subject's first police-registered road-traffic crash as a car driver (n = 12,502). Information on household socioeconomic group was taken from the census of 1985, and data on completed education at age 28-30 were gathered from Sweden's Register of Education. Two categories of crash severity were analysed (minor/no injury and severe/fatal injury), and also five crash circumstances (based on a classification of five crash descriptors). Both crash severity and crash circumstances are unequally distributed across social groups among young adult drivers. Social patterning is more pronounced for severe injuries/fatalities, and is consistently so across crash circumstances depending on SEP of destination, particularly for males. Socioeconomic differences are more pronounced for crash circumstances characterised as front-on and overtaking collisions and for single-vehicle crashes (43% of total crashes). In conclusion,the excess risk of young drivers from lower socioeconomic groups is consistent over crash severity but more pronounced as severity increases and for certain crash circumstances. PMID:15587501

  8. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this section when tested according to S8, S16, and S18 of 49 CFR 571.208. (b) Each vehicle subject to the requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air...

  9. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this section when tested according to S8, S16, and S18 of 49 CFR 571.208. (b) Each vehicle subject to the requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air...

  10. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this section when tested according to S8, S16, and S18 of 49 CFR 571.208. (b) Each vehicle subject to the requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air...

  11. Symposium: Talking about Race and Whiteness in "Crash"

    ERIC Educational Resources Information Center

    Middleton, Joyce Irene

    2007-01-01

    Teaching films like "Crash" gives teachers and researchers the opportunity to discuss films as social texts that engage students in critical thinking and self-reflection. This particular movie is especially effective in its use of a pulp-fiction visual rhetoric. Unfortunately, the film equates and replaces the term "race" with the term "prejudice"…

  12. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this section when tested according to S8, S16, and S18 of 49 CFR 571.208. (b) Each vehicle subject to the requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air...

  13. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this section when tested according to S8, S16, and S18 of 49 CFR 571.208. (b) Each vehicle subject to the requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air...

  14. The Pope Air Force Base aircraft crash and burn disaster.

    PubMed

    Mozingo, David W; Barillo, David J; Holcomb, John B

    2005-01-01

    This report describes the initial hospital and burn center management of a mass casualty incident resulting from an aircraft crash and fire. One hundred thirty soldiers were injured, including 10 immediate fatalities. Womack Army Medical Center at Fort Bragg, North Carolina, managed the casualties and began receiving patients 15 minutes after the crash. As a result of repetitive training that included at least two mass casualty drills each year, the triage area and emergency department were cleared of all patients within 2 hours. Fifty patients were transferred to burn centers, including 43 patients to the US Army Institute of Surgical Research. This constitutes the largest single mass casualty incident experienced in the 57-year history of the Institute. All patients of the US Army Institute of Surgical Research survived to hospital discharge, and 34 returned to duty 3 months after the crash. The scenario of an on-ground aircraft explosion and fire approximates what might be seen as a result of an aircraft hijacking, bombing, or intentional crash. Lessons learned from this incident have utility in the planning of future response to such disasters.

  15. Orthopaedic trauma from road crashes: is enough being done?

    PubMed

    Donaldson, Lachlan H; Brooke, Kathryn; Faux, Steven G

    2009-02-01

    A file review of patients presenting to the Emergency Department of St Vincent's Hospital with fractures sustained in a road crash was completed to describe patterns of orthopaedic injury, acute intervention and separation as well as the cost of care for adult road crash victims. One-hundred and eighty-seven patients were included. 65.8% were male; 48.1% were pedestrians. Differing patterns of injury corresponded to the role of the patient in the road crash (eg, pedestrian, driver of vehicle, etc). The mean length of stay was 8.8 days. 35.2% of patients were prescribed a different analgesic at discharge to that which they had received in the previous 24 hours. 35.8% had a documented discussion regarding insurance matters, usually with a social worker. 11.9% were discharged to inpatient rehabilitation. 56.2% had orthopaedic follow-up arranged at discharge, while 4.8% were discharged to an outpatient rehabilitation clinic. The mean overall cost was $13 336, with patients aged over 65 costing the most. The quality of acute care for fractures sustained in road crashes could be improved with evidence-based analgesia management, increased screening for psychiatric sequelae, enhanced assistance with insurance matters and vocational issues, and closer follow-up. Further research into the impact of these factors on long-term recovery is warranted. PMID:19203336

  16. Car-Crash Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Ball, Penny L.; And Others

    1974-01-01

    Describes an interesting, inexpensive, and highly motivating experiment to study uniform and accelerated motion by measuring the position of a car as it crashes into a rigid wall. Data are obtained from a sequence of pictures made by a high speed camera. (Author/SLH)

  17. Investigation of work zone crash casualty patterns using association rules.

    PubMed

    Weng, Jinxian; Zhu, Jia-Zheng; Yan, Xuedong; Liu, Zhiyuan

    2016-07-01

    Investigation of the casualty crash characteristics and contributory factors is one of the high-priority issues in traffic safety analysis. In this paper, we propose a method based on association rules to analyze the characteristics and contributory factors of work zone crash casualties. A case study is conducted using the Michigan M-94/I-94/I-94BL/I-94BR work zone crash data from 2004 to 2008. The obtained association rules are divided into two parts including rules with high-lift, and rules with high-support for the further analysis. The results show that almost all the high-lift rules contain either environmental or occupant characteristics. The majority of association rules are centered on specific characteristics, such as drinking driving, the highway with more than 4 lanes, speed-limit over 40mph and not use of traffic control devices. It should be pointed out that some stronger associated rules were found in the high-support part. With the network visualization, the association rule method can provide more understandable results for investigating the patterns of work zone crash casualties. PMID:27038500

  18. Finite pressure effects on the tokamak sawtooth crash

    SciTech Connect

    Nishimura, Yasutaro

    1998-07-01

    The sawtooth crash is a hazardous, disruptive phenomenon that is observed in tokamaks whenever the safety factor at the magnetic axis is below unity. Recently, Tokamak Test Fusion Reactor (TFTR) experimental data has revealed interesting features of the dynamical pressure evolution during the crash phase. Motivated by the experimental results, this dissertation focuses on theoretical modeling of the finite pressure effects on the nonlinear stage of the sawtooth crash. The crash phase has been studied numerically employed a toroidal magnetohydrodynamic (MHD) initial value code deduced from the FAR code. For the first time, by starting from a concentric equilibrium, it has been shown that the evolution through an m/n = 1/1 magnetic island induces secondary high-n ballooning instabilities. The magnetic island evolution gives rise to convection of the pressure inside the inversion radius and builds up a steep pressure gradient across the island separatrix, or current sheet, and thereby triggers ballooning instabilities below the threshold for the axisymmetric equilibrium. Due to the onset of secondary ballooning modes, concomitant fine scale vortices and magnetic stochasticity are generated. These effects produce strong flows across the current sheet, and thereby significant modify the m = 1 driven magnetic reconnection process. The resultant interaction of the high-n ballooning modes with the magnetic reconnection process is discussed.

  19. STOCK MARKET CRASH AND EXPECTATIONS OF AMERICAN HOUSEHOLDS*

    PubMed Central

    HUDOMIET, PÉTER; KÉZDI, GÁBOR; WILLIS, ROBERT J.

    2011-01-01

    SUMMARY This paper utilizes data on subjective probabilities to study the impact of the stock market crash of 2008 on households’ expectations about the returns on the stock market index. We use data from the Health and Retirement Study that was fielded in February 2008 through February 2009. The effect of the crash is identified from the date of the interview, which is shown to be exogenous to previous stock market expectations. We estimate the effect of the crash on the population average of expected returns, the population average of the uncertainty about returns (subjective standard deviation), and the cross-sectional heterogeneity in expected returns (disagreement). We show estimates from simple reduced-form regressions on probability answers as well as from a more structural model that focuses on the parameters of interest and separates survey noise from relevant heterogeneity. We find a temporary increase in the population average of expectations and uncertainty right after the crash. The effect on cross-sectional heterogeneity is more significant and longer lasting, which implies substantial long-term increase in disagreement. The increase in disagreement is larger among the stockholders, the more informed, and those with higher cognitive capacity, and disagreement co-moves with trading volume and volatility in the market. PMID:21547244

  20. Crash simulations of wheelchair-occupant systems in transport.

    PubMed

    Kang, W; Pilkey, W D

    1998-01-01

    A nonlinear multirigid body dynamic computer model has been developed to simulate the dynamic responses of a wheelchair-occupant system in a vehicle during a crash. The occupant, restrained by safety belts, is seated in a wheelchair that is, in turn, tied down in a vehicle. Validated extensively by crash sled tests at three laboratories, this model has been used to predict the responses of wheelchair-occupant systems in various crash environments. To evaluate the crashworthiness of different wheelchair tie-downs, the sensitivity of several design parameters, such as tiedown stiffness, wheel stiffness, and tiedown positions, has been studied using this model, and optimal values of these parameters for the wheelchair-occupant system have been obtained. Moreover, the model has been used to study the sensitivity of crash sled test pulse corridors in an effort to develop a sled test standard. It has been found that an existing ISO corridor allows large variation and should be "tightened." The model was implemented using a version of the multibody dynamic simulator, the Articulated Total Body program. PMID:9505255

  1. School Bus Crash Rates on Routine and Nonroutine Routes

    ERIC Educational Resources Information Center

    O'Neal, Elizabeth; Ramirez, Marizen; Hamann, Cara; Young, Tracy; Stahlhut, Mary; Peek-Asa, Corinne

    2014-01-01

    Background: Although prior research has established that school buses are a safe form of transportation, crashes can produce catastrophic consequences. School buses have 2 types of routes: predictable, routine routes that take children to and from school and less predictable, nonroutine routes for school events. No studies have examined school bus…

  2. Magnetorheological impact seat suspensions for ground vehicle crash mitigation

    NASA Astrophysics Data System (ADS)

    Bai, Xian-Xu; Wereley, Norman M.

    2014-04-01

    Semi-active magnetorheological energy absorbers (MREAs) are one type of the most promising actuator for both the vibration and shock control. This paper investigates the frontal crash mitigation performance of semi-active MR impact seat suspensions for ground vehicles. The characteristics of two MREAs, a conventional MREA and an MREA with an internal bypass, with an identical volume, are theoretically evaluated and compared. To explore the control effectiveness of MREAs in the shock control systems, the mechanical model of a 4-degree-of-freedom (4DOF) sliding seat suspension system with MREAs is constructed. An optimal Bingham number control, which is to minimize the crash pulse loads transmitted to occupants by utilizing maximum stroke of the MREAs based on initial velocity of crash pulse, mass, and damping, is proposed and developed to improve the crash mitigation performance of the 4DOF MR sliding seat suspension control systems. The simulated control performances of the mitigation systems based on the MREAs with different functional structures are evaluated, compared, and analyzed. The research results indicate that (1) the constant stroking load velocity range of the MREAs is of significance to evaluate the controllability of the MREAs (i.e., the effectiveness of the semi-active shock control systems), and (2) suboptimal Bingham number control cannot realize "soft landing" (i.e., either an end-stop impact or incomplete utilization of the MREA stroke happens).

  3. Teenaged Drivers and Fatal Crash Responsibility. Preliminary Report.

    ERIC Educational Resources Information Center

    Williams, Allan F.; Karpf, Ronald S.

    According to data obtained for the year 1978 from the Fatal Accident Reporting System (FARS) and from state governments under contract to the National Highway Traffic Safety Administration, teenaged drivers (especially males) have much higher rates of fatal crash involvement than older drivers. In addition, teenaged drivers are more likely than…

  4. Note on log-periodic description of 2008 financial crash

    NASA Astrophysics Data System (ADS)

    Bolonek-Lason, Katarzyna; Kosinski, Piotr

    2011-11-01

    We analyse the financial crash in 2008 for different financial markets from the point of view of log-periodic function model. In particular, we consider Dow Jones index, DAX index and Hang Seng index. We shortly discuss the possible relation of the theory of critical phenomena in physics to financial markets.

  5. The Pope Air Force Base aircraft crash and burn disaster.

    PubMed

    Mozingo, David W; Barillo, David J; Holcomb, John B

    2005-01-01

    This report describes the initial hospital and burn center management of a mass casualty incident resulting from an aircraft crash and fire. One hundred thirty soldiers were injured, including 10 immediate fatalities. Womack Army Medical Center at Fort Bragg, North Carolina, managed the casualties and began receiving patients 15 minutes after the crash. As a result of repetitive training that included at least two mass casualty drills each year, the triage area and emergency department were cleared of all patients within 2 hours. Fifty patients were transferred to burn centers, including 43 patients to the US Army Institute of Surgical Research. This constitutes the largest single mass casualty incident experienced in the 57-year history of the Institute. All patients of the US Army Institute of Surgical Research survived to hospital discharge, and 34 returned to duty 3 months after the crash. The scenario of an on-ground aircraft explosion and fire approximates what might be seen as a result of an aircraft hijacking, bombing, or intentional crash. Lessons learned from this incident have utility in the planning of future response to such disasters. PMID:15756114

  6. Nonparametric Analyses of Log-Periodic Precursors to Financial Crashes

    NASA Astrophysics Data System (ADS)

    Zhou, Wei-Xing; Sornette, Didier

    We apply two nonparametric methods to further test the hypothesis that log-periodicity characterizes the detrended price trajectory of large financial indices prior to financial crashes or strong corrections. The term "parametric" refers here to the use of the log-periodic power law formula to fit the data; in contrast, "nonparametric" refers to the use of general tools such as Fourier transform, and in the present case the Hilbert transform and the so-called (H, q)-analysis. The analysis using the (H, q)-derivative is applied to seven time series ending with the October 1987 crash, the October 1997 correction and the April 2000 crash of the Dow Jones Industrial Average (DJIA), the Standard & Poor 500 and Nasdaq indices. The Hilbert transform is applied to two detrended price time series in terms of the ln(tc-t) variable, where tc is the time of the crash. Taking all results together, we find strong evidence for a universal fundamental log-frequency f=1.02±0.05 corresponding to the scaling ratio λ=2.67±0.12. These values are in very good agreement with those obtained in earlier works with different parametric techniques. This note is extracted from a long unpublished report with 58 figures available at , which extensively describes the evidence we have accumulated on these seven time series, in particular by presenting all relevant details so that the reader can judge for himself or herself the validity and robustness of the results.

  7. Aircraft-crash-protected roof design for the European SBWR

    SciTech Connect

    Posta, B.A.; Kadar, I.; Rao, A.S.

    1995-12-31

    The European utility requirement document (EURD) places significant emphasis on aircraft crash protection of the reactor building - Alternative concepts were evaluated for protecting the dry-well head and the fuel pool from the effect of the spalling concrete for the General Electric Company`s European simplified boiling water reactor (ESBWR) designs.

  8. Effects of Enforcement Intensity on Alcohol Impaired Driving Crashes

    PubMed Central

    Fell, James C.; Waehrer, Geetha; Voas, Robert B.; Auld-Owens, Amy; Carr, Katie; Pell, Karen

    2014-01-01

    Background Research measuring levels of enforcement has investigated whether increases in police activities (e.g., checkpoints, driving-while-intoxicated [DWI] special patrols) above some baseline level are associated with reduced crashes and fatalities. Little research, however, has attempted to quantitatively measure enforcement efforts and relate different enforcement levels to specific levels of the prevalence of alcohol-impaired driving. Objective The objective of this study was to investigate the effects of law-enforcement intensity in a sample of communities on the rate of crashes involving a drinking driver. We analyzed the influence of different enforcement strategies and measures: (1) specific deterrence -annual number of driving-under-the-influence (DUI) arrests per capita; (2) general deterrence -frequency of sobriety checkpoint operations; (3) highly visible traffic enforcement -annual number of traffic stops per capita; (4) enforcement presence - number of sworn officers per capita; and (5) overall traffic enforcement - the number of other traffic enforcement citations per capita (i.e., seat belt citations, speeding tickets, and other moving violations and warnings) in each community. Methods We took advantage of nationwide data on the local prevalence of impaired driving from the 2007 National Roadside Survey (NRS), measures of DUI enforcement activity provided by the police departments that participated in the 2007 NRS, and crashes from the General Estimates System (GES) in the same locations as the 2007 NRS. We analyzed the relationship between the intensity of enforcement and the prevalence of impaired driving crashes in 22 to 26 communities with complete data. Log-linear regressions were used throughout the study. Results A higher number of DUI arrests per 10,000 driving-aged population was associated with a lower ratio of drinking-driver crashes to non-drinking-driver crashes (p=0.035) when controlling for the percentage of legally intoxicated

  9. Safety performance functions for crash severity on undivided rural roads.

    PubMed

    Russo, Francesca; Busiello, Mariarosaria; Dell'Acqua, Gianluca

    2016-08-01

    The objective of this paper is to explore the effect of the road features of two-lane rural road networks on crash severity. One of the main goals is to calibrate Safety Performance Functions (SPFs) that can predict the frequency per year of injuries and fatalities on homogeneous road segments. It was found that on more than 2000km of study-road network that annual average daily traffic, lane width, curvature change rate, length, and vertical grade are important variables in explaining the severity of crashes. A crash database covering a 5-year period was examined to achieve the goals (1295 injurious crashes that included 2089 injuries and 235 fatalities). A total of 1000km were used to calibrate SPFs and the remaining 1000km reflecting the traffic, geometric, functional features of the preceding one were used to validate their effectiveness. A negative binomial regression model was used. Reflecting the crash configurations of the dataset and maximizing the validation outcomes, four main sets of SPFs were developed as follows: (a) one equation to predict only injury frequency per year for the subset where only non-fatal injuries occurred, (b) two different equations to predict injury frequency and fatality frequency per year per sub-set where at least one fa tality occurred together with one injury, and (c) only one equation to predict the total frequency per year of total casualties correlating accurate percentages to obtain the final expected frequency of injuries and fatalities per year on homogeneous road segments. Residual analysis confirms the effectiveness of the SPFs.

  10. Comorbidities and Crash Involvement among Younger and Older Drivers

    PubMed Central

    Papa, Michela; Boccardi, Virginia; Prestano, Raffaele; Angellotti, Edith; Desiderio, Manuela; Marano, Luigi; Rizzo, Maria Rosaria; Paolisso, Giuseppe

    2014-01-01

    Previous studies identified comorbidities as predictors of older driver performance and driving pattern, while the direct impact of comorbidities on road crash risk in elderly drivers is still unknown. The present study is a cross-sectional aimed at investigating the association between levels of comorbidity and crash involvement in adult and elderly drivers. 327 drivers were stratified according to age range in two groups: elderly drivers (age ≥70 years old, referred as older) and adult drivers (age <70 years old, referred as younger). Driving information was obtained through a driving questionnaire. Distance traveled was categorized into low, medium and high on the basis of kilometers driven in a year. CIRS-illness severity (IS) and CIRS-comorbidity indices (CI) in all populations were calculated. Older drivers had a significantly higher crash involvements rate (p = .045) compared with the younger group based on the number of licensed drivers. Dividing comorbidity indices into tertiles among all licensed subjects, the number of current drivers significantly decreased (p<.0001) with increasing level of comorbidity. The number of current drivers among older subjects significantly decreased with increasing comorbidity level (p = .026) while no difference among younger group was found (p = .462). Among younger drivers with increasing comorbidity level, the number of road accidents significantly increased (p = .048) and the logistic regression analysis showed that comorbidity level significantly associated with crash involvement independent of gender and driving exposure. Older subjects with high level of comorbidity are able to self-regulate driving while comorbidity burden represents a significant risk factor for crash involvements among younger drivers. PMID:24722619

  11. The risk of groundling fatalities from unintentional airplane crashes.

    PubMed

    Thompson, K M; Rabouw, R F; Cooke, R M

    2001-12-01

    The crashes of four hijacked commercial planes on September 11, 2001, and the repeated televised images of the consequent collapse of the World Trade Center and one side of the Pentagon will inevitably change people's perceptions of the mortality risks to people on the ground from crashing airplanes. Goldstein and colleagues were the first to quantify the risk for Americans of being killed on the ground from a crashing airplane for unintentional events, providing average point estimates of 6 in a hundred million for annual risk and 4.2 in a million for lifetime risk. They noted that the lifetime risk result exceeded the commonly used risk management threshold of 1 in a million, and suggested that the risk to "groundlings" could be a useful risk communication tool because (a) it is a man-made risk (b) arising from economic activities (c) from which the victims derive no benefit and (d) exposure to which the victims cannot control. Their results have been used in risk communication. This analysis provides updated estimates of groundling fatality risks from unintentional crashes using more recent data and a geographical information system approach to modeling the population around airports. The results suggest that the average annual risk is now 1.2 in a hundred million and the lifetime risk is now 9 in ten million (below the risk management threshold). Analysis of the variability and uncertainty of this estimate, however, suggests that the exposure to groundling fatality risk varies by about a factor of approximately 100 in the spatial dimension of distance to an airport, with the risk declining rapidly outside the first 2 miles around an airport. We believe that the risk to groundlings from crashing airplanes is more useful in the context of risk communication when information about variability and uncertainty in the risk estimates is characterized, but we suspect that recent events will alter its utility in risk communication. PMID:11824678

  12. Active Collision Avoidance for Planetary Landers

    NASA Technical Reports Server (NTRS)

    Rickman, Doug; Hannan, Mike; Srinivasan, Karthik

    2014-01-01

    Present day robotic missions to other planets require precise, a priori knowledge of the terrain to pre-determine a landing spot that is safe. Landing sites can be miles from the mission objective, or, mission objectives may be tailored to suit landing sites. Future robotic exploration missions should be capable of autonomously identifying a safe landing target within a specified target area selected by mission requirements. Such autonomous landing sites must (1) 'see' the surface, (2) identify a target, and (3) land the vehicle. Recent advances in radar technology have resulted in small, lightweight, low power radars that are used for collision avoidance and cruise control systems in automobiles. Such radar systems can be adapted for use as active hazard avoidance systems for planetary landers. The focus of this CIF proposal is to leverage earlier work on collision avoidance systems for MSFC's Mighty Eagle lander and evaluate the use of automotive radar systems for collision avoidance in planetary landers.

  13. A model-based, multichannel, real-time capable sawtooth crash detector

    NASA Astrophysics Data System (ADS)

    van den Brand, H.; de Baar, M. R.; van Berkel, M.; Blanken, T. C.; Felici, F.; Westerhof, E.; Willensdorfer, M.; The ASDEX Upgrade Team; The EUROfusion MST1 Team

    2016-07-01

    Control of the time between sawtooth crashes, necessary for ITER and DEMO, requires real-time detection of the moment of the sawtooth crash. In this paper, estimation of sawtooth crash times is demonstrated using the model-based interacting multiple model (IMM) estimator, based on simplified models for the sawtooth crash. In contrast to previous detectors, this detector uses the spatial extent of the sawtooth crash as detection characteristic. The IMM estimator is tuned and applied to multiple ECE channels at once. A model for the sawtooth crash is introduced, which is used in the IMM algorithm. The IMM algorithm is applied to seven datasets from the ASDEX Upgrade tokamak. Five crash models with different mixing radii are used. All sawtooth crashes that have been identified beforehand by visual inspection of the data, are detected by the algorithm. A few additional detections are made, which upon closer inspection are seen to be sawtooth crashes, which show a partial reconnection. A closer inspection of the detected normal crashes shows that about 42% are not well fitted by any of the full reconnection models and show some characteristics of a partial reconnection. In some case, the measurement time is during the sawtooth crashes, which also results in an incorrect estimate of the mixing radius. For data provided at a sampling rate of 1 kHz, the run time of the IMM estimator is below 1 ms, thereby fulfilling real-time requirements.

  14. Bootstrap resampling approach to disaggregate analysis of road crashes in Hong Kong.

    PubMed

    Pei, Xin; Sze, N N; Wong, S C; Yao, Danya

    2016-10-01

    Road safety affects health and development worldwide; thus, it is essential to examine the factors that influence crashes and injuries. As the relationships between crashes, crash severity, and possible risk factors can vary depending on the type of collision, we attempt to develop separate prediction models for different crash types (i.e., single- versus multi-vehicle crashes and slight injury versus killed and serious injury crashes). Taking advantage of the availability of crash and traffic data disaggregated by time and space, it is possible to identify the factors that may contribute to crash risks in Hong Kong, including traffic flow, road design, and weather conditions. To remove the effects of excess zeros on prediction performance in a highly disaggregated crash prediction model, a bootstrap resampling method is applied. The results indicate that more accurate and reliable parameter estimates, with reduced standard errors, can be obtained with the use of a bootstrap resampling method. Results revealed that factors including rainfall, geometric design, traffic control, and temporal variations all determined the crash risk and crash severity. This helps to shed light on the development of remedial engineering and traffic management and control measures.

  15. Influence of the strain path on crash properties of a crash-box structure by experimental and numerical approaches

    NASA Astrophysics Data System (ADS)

    Durrenberger, L.; Even, D.; Molinari, A.; Rusinek, A.

    2006-08-01

    In order to reduce the gas emission without decreasing the passengers safety, the UHSS (Ultra High Strength Steel) steels are more and more used in the automotive industry. The very high mechanical characteristics of these steels allow to reduce the car weight thanks to the thickness reduction of the structure parts. The aim of this study is to analyse the plastic pre-strain effect (forming) on the crash properties of a crash-box structure. In order to achieve this goal, experimental rheological tests have been performed by combining quasi-static tensile tests followed by dynamic tensile test (8.10 - 3 s - 1 ≤ dot{\\varepsilon} ≤ 1000 s - 1) for a TRIP steel produced by ARCELOR. The combination of these results allows to obtain a better understanding of the steel behaviour in dynamic loading under different strain paths. All these information are necessary for an efficient simulation of crash test by including a pertinent material response. A special attention is given to the influence of the previous forming process on the dynamical response of crash boxes.

  16. The effects of age, gender, and crash types on drivers' injury-related health care costs.

    PubMed

    Shen, Sijun; Neyens, David M

    2015-04-01

    There are many studies that evaluate the effects of age, gender, and crash types on crash related injury severity. However, few studies investigate the effects of those crash factors on the crash related health care costs for drivers that are transported to hospital. The purpose of this study is to examine the relationships between drivers' age, gender, and the crash types, as well as other crash characteristics (e.g., not wearing a seatbelt, weather condition, and fatigued driving), on the crash related health care costs. The South Carolina Crash Outcome Data Evaluation System (SC CODES) from 2005 to 2007 was used to construct six separate hierarchical linear regression models based on drivers' age and gender. The results suggest that older drivers have higher health care costs than younger drivers and male drivers tend to have higher health care costs than female drivers in the same age group. Overall, single vehicle crashes had the highest health care costs for all drivers. For males older than 64-years old sideswipe crashes are as costly as single vehicle crashes. In general, not wearing a seatbelt, airbag deployment, and speeding were found to be associated with higher health care costs. Distraction-related crashes are more likely to be associated with lower health care costs in most cases. Furthermore this study highlights the value of considering drivers in subgroups, as some factors have different effects on health care costs in different driver groups. Developing an understanding of longer term outcomes of crashes and their characteristics can lead to improvements in vehicle technology, educational materials, and interventions to reduce crash-related health care costs.

  17. Crash risk analysis for Shanghai urban expressways: A Bayesian semi-parametric modeling approach.

    PubMed

    Yu, Rongjie; Wang, Xuesong; Yang, Kui; Abdel-Aty, Mohamed

    2016-10-01

    Urban expressway systems have been developed rapidly in recent years in China; it has become one key part of the city roadway networks as carrying large traffic volume and providing high traveling speed. Along with the increase of traffic volume, traffic safety has become a major issue for Chinese urban expressways due to the frequent crash occurrence and the non-recurrent congestions caused by them. For the purpose of unveiling crash occurrence mechanisms and further developing Active Traffic Management (ATM) control strategies to improve traffic safety, this study developed disaggregate crash risk analysis models with loop detector traffic data and historical crash data. Bayesian random effects logistic regression models were utilized as it can account for the unobserved heterogeneity among crashes. However, previous crash risk analysis studies formulated random effects distributions in a parametric approach, which assigned them to follow normal distributions. Due to the limited information known about random effects distributions, subjective parametric setting may be incorrect. In order to construct more flexible and robust random effects to capture the unobserved heterogeneity, Bayesian semi-parametric inference technique was introduced to crash risk analysis in this study. Models with both inference techniques were developed for total crashes; semi-parametric models were proved to provide substantial better model goodness-of-fit, while the two models shared consistent coefficient estimations. Later on, Bayesian semi-parametric random effects logistic regression models were developed for weekday peak hour crashes, weekday non-peak hour crashes, and weekend non-peak hour crashes to investigate different crash occurrence scenarios. Significant factors that affect crash risk have been revealed and crash mechanisms have been concluded.

  18. Crash risk analysis for Shanghai urban expressways: A Bayesian semi-parametric modeling approach.

    PubMed

    Yu, Rongjie; Wang, Xuesong; Yang, Kui; Abdel-Aty, Mohamed

    2016-10-01

    Urban expressway systems have been developed rapidly in recent years in China; it has become one key part of the city roadway networks as carrying large traffic volume and providing high traveling speed. Along with the increase of traffic volume, traffic safety has become a major issue for Chinese urban expressways due to the frequent crash occurrence and the non-recurrent congestions caused by them. For the purpose of unveiling crash occurrence mechanisms and further developing Active Traffic Management (ATM) control strategies to improve traffic safety, this study developed disaggregate crash risk analysis models with loop detector traffic data and historical crash data. Bayesian random effects logistic regression models were utilized as it can account for the unobserved heterogeneity among crashes. However, previous crash risk analysis studies formulated random effects distributions in a parametric approach, which assigned them to follow normal distributions. Due to the limited information known about random effects distributions, subjective parametric setting may be incorrect. In order to construct more flexible and robust random effects to capture the unobserved heterogeneity, Bayesian semi-parametric inference technique was introduced to crash risk analysis in this study. Models with both inference techniques were developed for total crashes; semi-parametric models were proved to provide substantial better model goodness-of-fit, while the two models shared consistent coefficient estimations. Later on, Bayesian semi-parametric random effects logistic regression models were developed for weekday peak hour crashes, weekday non-peak hour crashes, and weekend non-peak hour crashes to investigate different crash occurrence scenarios. Significant factors that affect crash risk have been revealed and crash mechanisms have been concluded. PMID:26847949

  19. Fatal Traffic Crashes Involving Drinking Drivers: What have we Learned?

    PubMed Central

    Fell, James C.; Tippetts, A. Scott; Voas, Robert B.

    2009-01-01

    Alcohol involvement in fatal crashes (any driver with a blood alcohol concentration [BAC] = .01g/dL or greater) in 2007 was more than three times higher at night (6 p.m.–6 a.m.) than during the day (6 a.m.–6 p.m.) (62% versus 19%). Alcohol involvement was 35% during weekdays compared to 54% on weekends. Nearly one in four drivers (23%) of personal vehicles (e.g., passenger cars or light trucks) and more than one in four motorcyclists (27%) in fatal crashes were intoxicated (i.e., had a BAC equal to or greater than the .08 g/dL illegal limit in the United States). In contrast, only 1% of the commercial drivers of heavy trucks had BACs equal to .08 g/dL or higher. More than a quarter (26%) of the drivers with high BACs (≥.15 g/dL) did not have valid licenses. The 21- to 24-age group had the highest proportion (35%) of drivers with BACs≥.08 g/dL, followed by the 25- to 34-age group (29%). The oldest and the youngest drivers had the lowest percentages of BACs≥ .08 g/dL: those aged 75 or older were at 4%, and those aged 16 to 20 were at 17%. Utah had the lowest rate of intoxicated drivers in fatal crashes at one in every eight drivers (12%), followed by Kentucky, Indiana, Iowa, New Hampshire, and Kansas, all at 17%. Montana (31%), South Carolina (31%), and North Dakota (39%) all had more than 3 in 10 drivers in fatal crashes who were intoxicated in 2007. The United States enjoyed a remarkable downward trend in alcohol-related crashes between 1982 and 1995, which has since leveled off. That trend coincided with a period during which per capita national alcohol consumption declined, the number of young drivers decreased, and the proportion of female drivers increased. Those factors alone, however, did not appear to account for the overall reduction. This provides further evidence that impaired-driving laws and safety program activity may have been responsible for at least some of the decline. However, there was a general worldwide decline in alcohol

  20. Fatal traffic crashes involving drinking drivers: what have we learned?

    PubMed

    Fell, James C; Tippetts, A Scott; Voas, Robert B

    2009-10-01

    Alcohol involvement in fatal crashes (any driver with a blood alcohol concentration [BAC] = .01g/dL or greater) in 2007 was more than three times higher at night (6 p.m.-6 a.m.) than during the day (6 a.m.-6 p.m.) (62% versus 19%). Alcohol involvement was 35% during weekdays compared to 54% on weekends. Nearly one in four drivers (23%) of personal vehicles (e.g., passenger cars or light trucks) and more than one in four motorcyclists (27%) in fatal crashes were intoxicated (i.e., had a BAC equal to or greater than the .08 g/dL illegal limit in the United States). In contrast, only 1% of the commercial drivers of heavy trucks had BACs equal to .08 g/dL or higher. More than a quarter (26%) of the drivers with high BACs (>or=.15 g/dL) did not have valid licenses. The 21- to 24-age group had the highest proportion (35%) of drivers with BACs>or=.08 g/dL, followed by the 25- to 34-age group (29%). The oldest and the youngest drivers had the lowest percentages of BACs>or= .08 g/dL: those aged 75 or older were at 4%, and those aged 16 to 20 were at 17%. Utah had the lowest rate of intoxicated drivers in fatal crashes at one in every eight drivers (12%), followed by Kentucky, Indiana, Iowa, New Hampshire, and Kansas, all at 17%. Montana (31%), South Carolina (31%), and North Dakota (39%) all had more than 3 in 10 drivers in fatal crashes who were intoxicated in 2007. The United States enjoyed a remarkable downward trend in alcohol-related crashes between 1982 and 1995, which has since leveled off. That trend coincided with a period during which per capita national alcohol consumption declined, the number of young drivers decreased, and the proportion of female drivers increased. Those factors alone, however, did not appear to account for the overall reduction. This provides further evidence that impaired-driving laws and safety program activity may have been responsible for at least some of the decline. However, there was a general worldwide decline in alcohol

  1. Landing Hazard Avoidance Display

    NASA Technical Reports Server (NTRS)

    Abernathy, Michael Franklin (Inventor); Hirsh, Robert L. (Inventor)

    2016-01-01

    Landing hazard avoidance displays can provide rapidly understood visual indications of where it is safe to land a vehicle and where it is unsafe to land a vehicle. Color coded maps can indicate zones in two dimensions relative to the vehicles position where it is safe to land. The map can be simply green (safe) and red (unsafe) areas with an indication of scale or can be a color coding of another map such as a surface map. The color coding can be determined in real time based on topological measurements and safety criteria to thereby adapt to dynamic, unknown, or partially known environments.

  2. Tractor-trailer crashes in Indiana: a case-control study of the role of truck configuration.

    PubMed

    Braver, E R; Zador, P L; Thum, D; Mitter, E L; Baum, H M; Vilardo, F J

    1997-01-01

    Studies of the crash experience of tractors pulling multiple trailers have reached different conclusions concerning the relationship of truck configuration to crash risk. A previous case-control study found a significant increase in crash risk for double-trailer trucks in the state of Washington. The present case-control study was done of tractor-trailers crashing on Indiana interstates during November 1989-March 1991. Controls were obtained for 25% of the crash sites and were all tractor-trailers passing the crash sites during a traffic observation session one to four weeks following a crash on the same day of the week for 30 minutes at the same time of day. Logistic regression identified day of week, time of day, urban/rural area, and specific highway as significant predictors of controls' truck configuration. This model was applied to the cases to estimate the expected number of double-trailer cases. For all crashes combined, no increased crash risk was observed for doubles (Standardized Crash Ratio (SCR) = 83). Doubles were significantly underinvolved in multiple-vehicle crashes (SCR = 74), crashes on dry roads (SCR = 61), and crashes on wet (other than snow, ice, or slush) roads (SCR = 54). Doubles were significantly overinvolved in crashes on roads with snow, ice, or slush (SCR = 153). Because truck configuration was highly associated with driver age and work operation attributes among trucks in crashes, the absence of control data on these potential confounders precluded definitive assessment of the intrinsic risk of multiple versus single-trailer vehicles.

  3. Validity of Surrogate Measures of Alcohol Involvement When Applied to Nonfatal Crashes

    PubMed Central

    Voas, Robert B.; Romano, Eduardo; Peck, Raymond

    2009-01-01

    Since the 1970s, nighttime fatal crashes have been used as a surrogate measure for alcohol-related fatalities for crashes for which more direct measures were absent. The validity of this approach was confirmed in 1985, but has not been re-evaluated since. Although this measure has also been applied to identify alcohol involvement in nonfatal crashes, its validity when applied to non-fatal cases has never been determined. The objective of this study was to evaluate the appropriateness of using nighttime crashes as surrogate measures for alcohol impairment when applied to fatal and nonfatal injury and property damage only (PDO) crashes. To do so, we used data from a crash-control design study collected at the roadside in two U.S. states between 1997 and 1999, as well as from the 1997–1999, and 2004–2006 Fatality Analysis Reporting System. The outcome of this study confirms the validity of using nighttime crashes as a surrogate measure for alcohol-related fatalities and supports the use of after-midnight crashes for measuring alcohol involvement in nonfatal and PDO crashes when the number of late-night crashes permits. PMID:19393802

  4. Single- versus multi-vehicle bicycle road crashes in Victoria, Australia.

    PubMed

    Boufous, Soufiane; de Rome, Liz; Senserrick, Teresa; Ivers, Rebecca Q

    2013-10-01

    The aim of the study is to compare trends, circumstances and outcomes of single- versus multi-vehicle bicycle on-road crashes in Victoria, Australia, through the analysis of police records and hospital admissions between January 2004 and December 2008. The results show that over 80% of on-road single-vehicle bicycle crashes occurred as a result of the cyclist losing control of the bicycle with the remainder involving collisions with objects. Compared with multi-vehicle crashes, single-vehicle crashes were more likely to occur in the dark, in wet conditions and in rural areas. Over half of the cyclists hospitalised as result of on-road crashes were injured in single-vehicle crashes and this proportion seems to be increasing over time. Single-vehicle crashes were associated with hospitalised injuries as severe as those resulting from multivehicle crashes. The findings highlight the significant burden of serious injury associated with single-vehicle bicycle road crashes. Further research is needed to investigate in greater detail the risk factors of these crashes and the effectiveness of countermeasures to reduce their burden. PMID:23435306

  5. Motor Vehicle Crash-Related Subdural Hematoma from Real-World Head Impact Data

    PubMed Central

    Urban, Jillian E.; Whitlow, Christopher T.; Edgerton, Colston A.; Powers, Alexander K.; Maldjian, Joseph A.

    2012-01-01

    Abstract Approximately 1,700,000 people sustain a traumatic brain injury (TBI) each year and motor vehicle crashes (MVCs) are a leading cause of hospitalization from TBI. Acute subdural hematoma (SDH) is a common intracranial injury that occurs in MVCs associated with high mortality and morbidity rates. In this study, SDH volume and midline shift have been analyzed in order to better understand occupant injury by correlating them to crash and occupant parameters. Fifty-seven head computed tomography (CT) scans were selected from the Crash Injury Research Engineering Network (CIREN) with Abbreviated Injury Scale (AIS) level 3+ SDH. Semi-automated methods were used to isolate the intracranial volume. SDH and additional occupant intracranial injuries were segmented across axial CT images, providing a total SDH injury volume. SDH volume was correlated to crash parameters and occupant characteristics. Results show a positive correlation between SDH volume and crash severity in near-side and frontal crashes. Additionally, the location of the resulting hemorrhage varied by crash type. Those with greater SDH volumes had significantly lower Glasgow Coma Scale (GCS) scores at the crash site in near-side crashes. Age and fracture type were found to be significant contributors to SDH volume. This study is a volumetric analysis of real world brain injuries and known MVC impacts. The results of this study demonstrate a relationship among SDH volume, crash mechanics, and occupant characteristics that provide a better understanding of the injury mechanisms of MVC-associated TBI. PMID:22928543

  6. Multivariate spatial models of excess crash frequency at area level: case of Costa Rica.

    PubMed

    Aguero-Valverde, Jonathan

    2013-10-01

    Recently, areal models of crash frequency have being used in the analysis of various area-wide factors affecting road crashes. On the other hand, disease mapping methods are commonly used in epidemiology to assess the relative risk of the population at different spatial units. A natural next step is to combine these two approaches to estimate the excess crash frequency at area level as a measure of absolute crash risk. Furthermore, multivariate spatial models of crash severity are explored in order to account for both frequency and severity of crashes and control for the spatial correlation frequently found in crash data. This paper aims to extent the concept of safety performance functions to be used in areal models of crash frequency. A multivariate spatial model is used for that purpose and compared to its univariate counterpart. Full Bayes hierarchical approach is used to estimate the models of crash frequency at canton level for Costa Rica. An intrinsic multivariate conditional autoregressive model is used for modeling spatial random effects. The results show that the multivariate spatial model performs better than its univariate counterpart in terms of the penalized goodness-of-fit measure Deviance Information Criteria. Additionally, the effects of the spatial smoothing due to the multivariate spatial random effects are evident in the estimation of excess equivalent property damage only crashes.

  7. Incidence and cost of alcohol-involved crashes in the United States.

    PubMed

    Miller, T R; Blincoe, L J

    1994-10-01

    The incidence of alcohol-involved highway crashes (those in which a driver or nonoccupant had been drinking) was estimated from federal data bases. The estimates were adjusted for police underreporting of alcohol involvement. In 1990, 22% of motor vehicle crash victims--1.2 million--were injured in crashes involving alcohol. Over 22,000 of these victims were killed. The comprehensive cost of alcohol-involved crashes was $148 billion in 1990, including $46 billion in monetary costs and $102 billion in lost quality of life. This represents $1.09 per drink of alcohol consumed. Crashes where blood alcohol concentration (BAC) exceeded .10% accounted for 32% of comprehensive crash costs, and crashes with lower positive BAC accounted for another 8%. Excluding drunk drivers and drunk nonoccupants, alcohol-involved crashes caused 8,500 deaths and left 21,000 people permanently disabled and another 605,000 less seriously injured. Averaged across all drinks, other people collectively pay $0.63 in crash costs every time someone takes a drink. A combination of increased public awareness and strong legal sanctions has been effective in reducing the incidence of alcohol-involved driving. The proportion of injuries in crashes that police reported were alcohol-involved dropped by 37% between 1982-1984 and 1990. PMID:7999203

  8. Avoidable waste management costs

    SciTech Connect

    Hsu, K.; Burns, M.; Priebe, S.; Robinson, P.

    1995-01-01

    This report describes the activity based costing method used to acquire variable (volume dependent or avoidable) waste management cost data for routine operations at Department of Energy (DOE) facilities. Waste volumes from environmental restoration, facility stabilization activities, and legacy waste were specifically excluded from this effort. A core team consisting of Idaho National Engineering Laboratory, Los Alamos National Laboratory, Rocky Flats Environmental Technology Site, and Oak Ridge Reservation developed and piloted the methodology, which can be used to determine avoidable waste management costs. The method developed to gather information was based on activity based costing, which is a common industrial engineering technique. Sites submitted separate flow diagrams that showed the progression of work from activity to activity for each waste type or treatability group. Each activity on a flow diagram was described in a narrative, which detailed the scope of the activity. Labor and material costs based on a unit quantity of waste being processed were then summed to generate a total cost for that flow diagram. Cross-complex values were calculated by determining a weighted average for each waste type or treatability group based on the volume generated. This study will provide DOE and contractors with a better understanding of waste management processes and their associated costs. Other potential benefits include providing cost data for sites to perform consistent cost/benefit analysis of waste minimization and pollution prevention (WMIN/PP) options identified during pollution prevention opportunity assessments and providing a means for prioritizing and allocating limited resources for WMIN/PP.

  9. Evaluation of the predictability of real-time crash risk models.

    PubMed

    Xu, Chengcheng; Liu, Pan; Wang, Wei

    2016-09-01

    The primary objective of the present study was to investigate the predictability of crash risk models that were developed using high-resolution real-time traffic data. More specifically the present study sought answers to the following questions: (a) how to evaluate the predictability of a real-time crash risk model; and (b) how to improve the predictability of a real-time crash risk model. The predictability is defined as the crash probability given the crash precursor identified by the crash risk model. An equation was derived based on the Bayes' theorem for estimating approximately the predictability of crash risk models. The estimated predictability was then used to quantitatively evaluate the effects of the threshold of crash precursors, the matched and unmatched case-control design, and the control-to-case ratio on the predictability of crash risk models. It was found that: (a) the predictability of a crash risk model can be measured as the product of prior crash probability and the ratio between sensitivity and false alarm rate; (b) there is a trade-off between the predictability and sensitivity of a real-time crash risk model; (c) for a given level of sensitivity, the predictability of the crash risk model that is developed using the unmatched case-controlled sample is always better than that of the model developed using the matched case-controlled sample; and (d) when the control-to-case ratio is beyond 4:1, the increase in control-to-case ratio does not lead to clear improvements in predictability.

  10. Investigation of time and weather effects on crash types using full Bayesian multivariate Poisson lognormal models.

    PubMed

    El-Basyouny, Karim; Barua, Sudip; Islam, Md Tazul

    2014-12-01

    Previous research shows that various weather elements have significant effects on crash occurrence and risk; however, little is known about how these elements affect different crash types. Consequently, this study investigates the impact of weather elements and sudden extreme snow or rain weather changes on crash type. Multivariate models were used for seven crash types using five years of daily weather and crash data collected for the entire City of Edmonton. In addition, the yearly trend and random variation of parameters across the years were analyzed by using four different modeling formulations. The proposed models were estimated in a full Bayesian context via Markov Chain Monte Carlo simulation. The multivariate Poisson lognormal model with yearly varying coefficients provided the best fit for the data according to Deviance Information Criteria. Overall, results showed that temperature and snowfall were statistically significant with intuitive signs (crashes decrease with increasing temperature; crashes increase as snowfall intensity increases) for all crash types, while rainfall was mostly insignificant. Previous snow showed mixed results, being statistically significant and positively related to certain crash types, while negatively related or insignificant in other cases. Maximum wind gust speed was found mostly insignificant with a few exceptions that were positively related to crash type. Major snow or rain events following a dry weather condition were highly significant and positively related to three crash types: Follow-Too-Close, Stop-Sign-Violation, and Ran-Off-Road crashes. The day-of-the-week dummy variables were statistically significant, indicating a possible weekly variation in exposure. Transportation authorities might use the above results to improve road safety by providing drivers with information regarding the risk of certain crash types for a particular weather condition.

  11. Transient analysis techniques in performing impact and crash dynamic studies

    NASA Technical Reports Server (NTRS)

    Pifko, A. B.; Winter, R.

    1989-01-01

    Because of the emphasis being placed on crashworthiness as a design requirement, increasing demands are being made by various organizations to analyze a wide range of complex structures that must perform safely when subjected to severe impact loads, such as those generated in a crash event. The ultimate goal of crashworthiness design and analysis is to produce vehicles with the ability to reduce the dynamic forces experienced by the occupants to specified levels, while maintaining a survivable envelope around them during a specified crash event. DYCAST is a nonlinear structural dynamic finite element computer code that started from the plans systems of a finite element program for static nonlinear structural analysis. The essential features of DYCAST are outlined.

  12. Plane down in the city: Operation Crash and Surge.

    PubMed

    Kann, Duane F; Draper, Thomas W

    2014-01-01

    This article is about the experiences gained from the largest full-scale exercise ever conducted in the State of Florida, specifically regarding the Orlando International Airport (MCO) venues. The exercise was centred on an airplane crashing into a hotel just outside of MCO property. The scenario clarified details regarding Incident Command and the unique jurisdictional responsibilities associated with a large-scale mass casualty incident. There were additional challenges with airline operations, walking wounded, and information sharing that provided valuable experiences toward enhancing emergency operations. This article also outlines information gained by the MCO "go team" that traveled to San Francisco following the crash of Asiana flight 214. This real-life incident shone a light on many of the strengths and opportunities found throughout the MCO exercise and this article shows the interrelationship of both of these invaluable experiences.

  13. Crash test for the restricted three-body problem.

    PubMed

    Nagler, Jan

    2005-02-01

    The restricted three-body problem serves to investigate the chaotic behavior of a small body under the gravitational influence of two heavy primary bodies. We analyze numerically the phase space mixing of bounded motion, escape, and crash in this simple model of (chaotic) celestial mechanics. The presented extensive numerical analysis reveals a high degree of complexity. We extend the recently presented findings for the Copenhagen case of equal main masses to the general case of different primary body masses. Collisions of the small body onto the primaries are comparatively frequent, and their probability displays a scale-free dependence on the size of the primaries as shown for the Copenhagen case. Interpreting the crash as leaking in phase space the results are related to both chaotic scattering and the theory of leaking Hamiltonian systems. PMID:15783407

  14. Crash test for the restricted three-body problem.

    PubMed

    Nagler, Jan

    2005-02-01

    The restricted three-body problem serves to investigate the chaotic behavior of a small body under the gravitational influence of two heavy primary bodies. We analyze numerically the phase space mixing of bounded motion, escape, and crash in this simple model of (chaotic) celestial mechanics. The presented extensive numerical analysis reveals a high degree of complexity. We extend the recently presented findings for the Copenhagen case of equal main masses to the general case of different primary body masses. Collisions of the small body onto the primaries are comparatively frequent, and their probability displays a scale-free dependence on the size of the primaries as shown for the Copenhagen case. Interpreting the crash as leaking in phase space the results are related to both chaotic scattering and the theory of leaking Hamiltonian systems.

  15. Epidemiology, Causes and Prevention of Car Rollover Crashes with Ejection

    PubMed Central

    El-Hennawy, HM; El-Menyar, A; Al-Thani, H; Tuma, M; Parchani, A; Abdulrahman, H; Peralta, R; Asim, M; Zarour, A; Latifi, R

    2014-01-01

    Rollover crashes (ROCs) are responsible for almost a third of all highway vehicle occupant fatalities. Although ROCs are common and serious mechanism of injury, ROCs are under-reported. To analyze the causes, mechanism, impact and prevention of ROCs, we reviewed the literature between 1984 and 2013. By utilizing the search engines PubMed, MEDLINE and EMBASE by using key words “ROCs” “Ejection” and “vehicle” the initial search yielded 241 abstracts, of which 58 articles were relevant. Most of the articles were either retrospective or experimental studies funded by automobile companies. All vehicles are susceptible to rollovers to certain extents. Despite continuing innovation in vehicles’ safety, human factor is pivotal in prevention of ROCs. Distracted driving, speeding and drinking escalate the chances of rollover crashes. Wearing a seatbelt greatly improves the chances of surviving a ROC. PMID:25221693

  16. Comparison of crashes during public holidays and regular weekends.

    PubMed

    Anowar, Sabreena; Yasmin, Shamsunnahar; Tay, Richard

    2013-03-01

    Traffic collisions and fatalities during the holiday festive periods are apparently on the rise in Alberta, Canada, despite the enhanced enforcement and publicity campaigns conducted during these periods. Using data from 2004 to 2008, this research identifies the factors that delineate between crashes that occur during public holidays and those occurring during normal weekends. We find that fatal and injury crashes are over-represented during holidays. Amongst the three risky behaviors targeted in the holiday blitzes (driver intoxication, unsafe speeding and restraint use), non-use of restraint is more prevalent whereas driver intoxication and unsafe speeding are less prevalent during holidays. The mixed results obtained suggest that it may be time to consider a more balanced approach to the enhanced enforcement and publicity campaigns.

  17. Identifying the Bottom Line after a Stock Market Crash

    NASA Astrophysics Data System (ADS)

    Roehner, B. M.

    In this empirical paper we show that in the months following a crash there is a distinct connection between the fall of stock prices and the increase in the range of interest rates for a sample of bonds. This variable, which is often referred to as the interest rate spread variable, can be considered as a statistical measure for the disparity in lenders' opinions about the future; in other words, it provides an operational definition of the uncertainty faced by economic agents. The observation that there is a strong negative correlation between stock prices and the spread variable relies on the examination of eight major crashes in the United States between 1857 and 1987. That relationship which has remained valid for one and a half century in spite of important changes in the organization of financial markets can be of interest in the perspective of Monte Carlo simulations of stock markets.

  18. A review of the analytical simulation of aircraft crash dynamics

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Carden, Huey D.; Boitnott, Richard L.; Hayduk, Robert J.

    1990-01-01

    A large number of full scale tests of general aviation aircraft, helicopters, and one unique air-to-ground controlled impact of a transport aircraft were performed. Additionally, research was also conducted on seat dynamic performance, load-limiting seats, load limiting subfloor designs, and emergency-locator-transmitters (ELTs). Computer programs were developed to provide designers with methods for predicting accelerations, velocities, and displacements of collapsing structure and for estimating the human response to crash loads. The results of full scale aircraft and component tests were used to verify and guide the development of analytical simulation tools and to demonstrate impact load attenuating concepts. Analytical simulation of metal and composite aircraft crash dynamics are addressed. Finite element models are examined to determine their degree of corroboration by experimental data and to reveal deficiencies requiring further development.

  19. Abnormal statistical properties of stock indexes during a financial crash

    NASA Astrophysics Data System (ADS)

    Li, Wei-Shen; Liaw, Sy-Sang

    2015-03-01

    We investigate minute indexes of stock markets in 10 countries during financial crashes by dividing them into several stages according to their stock price tendencies: plunging stage (stage 1), fluctuating or rebounding stage (stage 2), and soaring stage (stage 3). The tail distributions of the returns satisfy a power law for developed markets but show a dual power-law structure for emerging markets. Prominent dual fractal structures are found during the plunging stage in developed markets, and after the plunging stage in emerging markets. The fractal analysis on the sign series of the returns yields similar dual fractal properties. The magnitude series of the returns provides surprising results during a crash. We find that developed markets have strong and weak long-range persistence in plunging and soaring stage respectively, while emerging markets behave oppositely. These results indicate that different types of markets are influenced strongly by the external shock of a crisis at different stages.

  20. Plane down in the city: Operation Crash and Surge.

    PubMed

    Kann, Duane F; Draper, Thomas W

    2014-01-01

    This article is about the experiences gained from the largest full-scale exercise ever conducted in the State of Florida, specifically regarding the Orlando International Airport (MCO) venues. The exercise was centred on an airplane crashing into a hotel just outside of MCO property. The scenario clarified details regarding Incident Command and the unique jurisdictional responsibilities associated with a large-scale mass casualty incident. There were additional challenges with airline operations, walking wounded, and information sharing that provided valuable experiences toward enhancing emergency operations. This article also outlines information gained by the MCO "go team" that traveled to San Francisco following the crash of Asiana flight 214. This real-life incident shone a light on many of the strengths and opportunities found throughout the MCO exercise and this article shows the interrelationship of both of these invaluable experiences. PMID:24578020

  1. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    NASA Astrophysics Data System (ADS)

    Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

    2015-11-01

    Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

  2. Determinants of road traffic crash fatalities across Indian States.

    PubMed

    Grimm, Michael; Treibich, Carole

    2013-08-01

    This article explores the determinants of road traffic crash fatalities in India. In addition to income, the analysis considers the sociodemographic population structure, motorization levels, road and health infrastructure and road rule enforcement as potential factors. An original panel data set covering 25 Indian states is analyzed using multivariate regression analysis. Time and state fixed-effects account for unobserved heterogeneity across states and time. The rising motorization, urbanization and accompanying increase in the share of vulnerable road users, that is, pedestrians and two-wheelers, are the major drivers of road traffic crash fatalities in India. Among vulnerable road users, women form a particularly high-risk group. Higher expenditure per police officer is associated with a lower fatality rate. The results suggest that India should focus, in particular, on road infrastructure investments that allow the separation of vulnerable from other road users on improved road rule enforcement and should pay special attention to vulnerable female road users. PMID:22936645

  3. Behavior Of Aircraft Components Under Crash-Type Loads

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.

    1993-01-01

    Report presents overview of research involving use of concepts of aircraft elements and substructures not necessarily designed or optimized with respect to energy-absorption or crash-loading considerations. Experimental and analytical data presented in report indicate some general trends in failure behaviors of class of composite-material structures including individual fuselage frames, skeleton subfloors with stringers and floor beams but without skin covering, and subfloors with skin added to frame/stringer arrangement.

  4. Modeling the stock market prior to large crashes

    NASA Astrophysics Data System (ADS)

    Johansen, A.; Sornette, D.

    We propose that the minimal requirements for a model of stock market price fluctuations should comprise time asymmetry, robustness with respect to connectivity between agents, ``bounded rationality'' and a probabilistic description. We also compare extensively two previously proposed models of log-periodic behavior of the stock market index prior to a large crash. We find that the model which follows the above requirements outperforms the other with a high statistical significance.

  5. Light airplane crash tests at three flight-path angles

    NASA Technical Reports Server (NTRS)

    Castle, C. B.; Alfaro-Bou, E.

    1978-01-01

    Three similar twin engine general aviation airplane specimens were crash tested at Langley impact dynamics research facility at 27 m/sec and at flight-path angles of -15 deg, -30 deg, and -45 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  6. Car Crashes and Central Disorders of Hypersomnolence: A French Study

    PubMed Central

    Lopez, Regis; Pesenti, Carole; Plazzi, Giuseppe; Drouot, Xavier; Leu-Semenescu, Smaranda; Beziat, Severine; Arnulf, Isabelle; Dauvilliers, Yves

    2015-01-01

    Background Drowsiness compromises driving ability by reducing alertness and attentiveness, and delayed reaction times. Sleep-related car crashes account for a considerable proportion of accident at the wheel. Narcolepsy type 1 (NT1), narcolepsy type 2 (NT2) and idiopathic hypersomnia (IH) are rare central disorders of hypersomnolence, the most severe causes of sleepiness thus being potential dangerous conditions for both personal and public safety with increasing scientific, social, and political attention. Our main objective was to assess the frequency of recent car crashes in a large cohort of patients affected with well-defined central disorders of hypersomnolence versus subjects from the general population. Methods We performed a cross-sectional study in French reference centres for rare hypersomnia diseases and included 527 patients and 781 healthy subjects. All participants included needed to have a driving license, information available on potential accident events during the last 5 years, and on potential confounders; thus analyses were performed on 282 cases (71 IH, 82 NT2, 129 NT1) and 470 healthy subjects. Results Patients reported more frequently than healthy subjects the occurrence of recent car crashes (in the previous five years), a risk that was confirmed in both treated and untreated subjects at study inclusion (Untreated, OR = 2.21 95%CI = [1.30–3.76], Treated OR = 2.04 95%CI = [1.26–3.30]), as well as in all disease categories, and was modulated by subjective sleepiness level (Epworth scale and naps). Conversely, the risk of car accidents of patients treated for at least 5 years was not different to healthy subjects (OR = 1.23 95%CI = [0.56–2.69]). Main risk factors were analogous in patients and healthy subjects. Conclusion Patients affected with central disorders of hypersomnolence had increased risk of recent car crashes compared to subjects from the general population, a finding potentially reversed by long-term treatment. PMID:26052938

  7. Effectiveness of bans and laws in reducing traffic deaths: legalized Sunday packaged alcohol sales and alcohol-related traffic crashes and crash fatalities in New Mexico.

    PubMed

    McMillan, Garnett P; Lapham, Sandra

    2006-11-01

    We determined the relative risk of alcohol-related motor vehicle accidents and fatalities after New Mexico lifted its ban on Sunday packaged alcohol sales. We extracted all alcohol-related crashes from New Mexico police reports for 3652 days between July 1, 1990, and June 30, 2000, and found a 29% increase in alcohol-related crashes and a 42% increase in alcohol-related crash fatalities on Sundays after the ban on Sunday packaged alcohol sales was lifted. There was an estimated excess of 543.1 alcohol-related crashes and 41.6 alcohol-related crash fatalities on Sundays after the ban was lifted. Repealing the ban on Sunday packaged alcohol sales introduced a public health and safety hazard in New Mexico.

  8. A Study of Transport Airplane Crash-Resistant Fuel Systems

    NASA Technical Reports Server (NTRS)

    Jones, Lisa (Technical Monitor); Robertson, S. H.; Johnson, N. B.; Hall, D. S.; Rimson, I. J.

    2002-01-01

    This report presents the results of a study, funded by the Federal Aviation Administration (FAA), of transport airplane crash-resistant fuel system (CRFS). The report covers the historical studies related to aircraft crash fires and fuel containment concepts undertaken by the FAA, NASA, and the U.S. Army, which ultimately led to the current state of the art in CRFS technology. It describes the basic research, testing, field investigations and production efforts which have led to the highly successful military CRFS, which has saved many lives and reduced costs of accidents. Current CRFS technology used in transport category airplanes is defined and compared to the available state-of-the-art technology. The report provides information to the FAA and other government organizations which can help them plan their efforts to improve the state of crash fire protection in the transport airplane fleet. The report provides guidance to designers looking for information about CRFS design problems, analysis tools to use for product improvement, and a summary of current and proposed regulations for transport category airplane fuel systems.

  9. Digital video data archive for crash test systems

    NASA Astrophysics Data System (ADS)

    Hock, Christian

    1997-04-01

    Kayser-Threde has been invested many years in developing technology used in crash testing, data acquisition and test data archiving. Since 1976 the department Measurement Systems has ben supplying European car manufacturers and test houses with ruggedized on-board data acquisition units for use in safety tests according to SAE J 211. The integration of on-board high-speed digital cameras has completed the data acquisition unit. Stationary high-speed cameras for external observation are also included in the controlling and acquisition system of the crash test site. The occupation of Kayser-Threde's department High Speed Data Systems is the design and integration of computerized data flow systems under real-time conditions. The special circumstances of crash test applications are taken into account for data acquisition, mass storage and data distribution. The two fundamental components of the video data archiving systems are, firstly, the recording of digital high-speed images as well as digital test data and secondly, an organized filing in mass archiving systems with the capability of near on-line access. In combination with sophisticated and reliable hardware components Kayser-Threde is able to deliver high performance digital data archives with storage capacities of up to 2600 TeraBytes.

  10. Full-Scale Crash Test of an MD-500 Helicopter

    NASA Technical Reports Server (NTRS)

    Littell, Justin

    2011-01-01

    A full-scale crash test was successfully conducted in March 2010 of an MD-500 helicopter at NASA Langley Research Center s Landing and Impact Research Facility. The reasons for conducting this test were threefold: 1 To generate data to be used with finite element computer modeling efforts, 2 To study the crashworthiness features typically associated with a small representative helicopter, and 3 To compare aircraft response to data collected from a previously conducted MD-500 crash test, which included an externally deployable energy absorbing (DEA) concept. Instrumentation on the airframe included accelerometers on various structural components of the airframe; and strain gages on keel beams, skid gear and portions of the skin. Three Anthropomorphic Test Devices and a specialized Human Surrogate Torso Model were also onboard to collect occupant loads for evaluation with common injury risk criteria. This paper presents background and results from this crash test conducted without the DEA concept. These results showed accelerations of approximately 30 to 50 g on the airframe at various locations, little energy attenuation through the airframe, and moderate to high probability of occupant injury for a variety of injury criteria.

  11. Analysis of fatal road traffic crashes in Ghana.

    PubMed

    Ackaah, Williams; Adonteng, David O

    2011-03-01

    The major objective of this study was to identify the risk factors associated with fatal road traffic crashes (RTCs) and to propose remedial measures to address them. Fatal RTC data for the period 2005-2007 in Ghana were analysed using the Micro-computer Accident Analysis Package (MAAP) software. Other transport-related research works were reviewed and incorporated in the article. The study showed that pedestrians accounted for 42% of all road traffic fatalities and nearly one-third (33%) of these crashes occurred during the early night-time hours. Children alone constituted almost one-third of all pedestrian fatalities. The occupants of goods vehicles accounted for 12% of all road traffic fatalities although goods vehicles constitute just about 9% of the total motor vehicle population in Ghana. Pedestrians, especially children bear a disproportionately high share of road traffic fatalities in Ghana. The risk of being killed as a pedestrian in traffic is exacerbated during night time. Excessive vehicular speeds, inappropriate use of goods vehicles for passenger transport, excessive loading and inadequate trauma care are the key contributory risk factors to the high number of road traffic fatalities. Concerted efforts spanning education, engineering, enforcement and trauma care are needed to stem the rise in fatal crashes in Ghana.

  12. Simulating radiative shocks with the CRASH laser package

    NASA Astrophysics Data System (ADS)

    van der Holst, B.; Tóth, G.; Sokolov, I. V.; Torralva, B. R.; Powell, K. G.; Drake, R. P.; Klapisch, M.; Busquet, M.; Fryxell, B.; Myra, E. S.

    2013-03-01

    We present the latest improvements in the Center for Radiative Shock Hydrodynamics (CRASH) code, a parallel block-adaptive-mesh Eulerian code for simulating high-energy-density plasmas. The implementation can solve for radiation models with either a gray or a multigroup method in the flux-limited-diffusion approximation. The electrons and ions are allowed to be out of temperature equilibrium and flux-limited electron thermal heat conduction is included. We have recently implemented a CRASH laser package with 3-D ray tracing, resulting in improved energy deposition evaluation. New, more accurate opacity models are available which significantly improve radiation transport in materials like xenon. In addition, the HYPRE preconditioner has been added to improve the radiation implicit solver. With this updated version of the CRASH code we study radiative shock tube problems. In our set-up, a 1 ns, 3.8 kJ laser pulse irradiates a 20 micron beryllium disk, driving a shock into a xenon-filled plastic tube. The electrons emit radiation in the shocked xenon. This radiation preheats the unshocked xenon. Photons traveling ahead of the shock will also interact with the plastic tube, heat it, and in turn this can drive another shock off the wall into the xenon.

  13. Estimating overinvolvement of seat belt nonwearers in crashes and the effect of lap/shoulder restraint use on different crash severity consequences.

    PubMed

    Cooper, P J

    1994-04-01

    At least some of the controversy surrounding the level of effectiveness of seat belts has arisen due to the difficulty in calculating a direct impact on police-reported accident data. These data are notoriously biased in the direction of belt-wearing overestimation. Furthermore, not enough information on nonwearer overrepresentation in crash involvement is currently available over the entire range of accident severity levels. The work reported in this paper was undertaken in order to develop a methodology for calculating nonwearer overrepresentation at various levels of crash severity and for adjusting police-reported belt-wearing data. The underlying premise was that police officers make reasonably consistent and valid judgements related to probable fault or causor status in casualty-producing accidents that they attend. Separating reported wearer and nonwearer crash involvements into culpable and nonculpable situations led to a procedure for adjusting police-reported belt-wearing totals to account for likely overestimation and also enabled the assessment of probable levels of nonwearer overrepresentation in crashes at all severity levels. The results, in terms of both nonwearer overrepresentation and seat belt effectiveness, were comparable with those reported in the literature for fatal crash involvement. Seat belt effectiveness was found to average 49% for fatal crashes, 35% for serious-injury crashes, 18% for moderate-injury crashes, and 11% for minor-injury crashes. Belt nonwearer overrepresentation was found to increase with increasing levels of belt wearing in the driver population from a factor of between 2 and 5 (depending on crash severity) at b = 0.5 to between 5 and 10 as b approached 0.9.

  14. Avoiding dangerous climate change

    SciTech Connect

    Hans Joachim Schellnhuber; Wolfgang Cramer; Nebojsa Nakicenovic; Tom Wigley; Gary Yohe

    2006-02-15

    In 2005 the UK Government hosted the Avoiding Dangerous Climate Change conference to take an in-depth look at the scientific issues associated with climate change. This volume presents the most recent findings from the leading international scientists that attended the conference. The topics addressed include critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, socioeconomic costs and benefits of emissions pathways, and technological options for meeting different stabilisation levels of greenhouse gases in the atmosphere. Contents are: Foreword from Prime Minister Tony Blair; Introduction from Rajendra Pachauri, Chairman of the IPCC; followed by 41 papers arranged in seven sections entitled: Key Vulnerabilities of the Climate System and Critical Thresholds; General Perspectives on Dangerous Impacts; Key Vulnerabilities for Ecosystems and Biodiversity; Socio-Economic Effects; Regional Perspectives; Emission Pathways; and Technological Options. Four papers have been abstracted separately for the Coal Abstracts database.

  15. Comparing and validating models of driver steering behaviour in collision avoidance and vehicle stabilisation

    NASA Astrophysics Data System (ADS)

    Markkula, G.; Benderius, O.; Wahde, M.

    2014-12-01

    A number of driver models were fitted to a large data set of human truck driving, from a simulated near-crash, low-friction scenario, yielding two main insights: steering to avoid a collision was best described as an open-loop manoeuvre of predetermined duration, but with situation-adapted amplitude, and subsequent vehicle stabilisation could to a large extent be accounted for by a simple yaw rate nulling control law. These two phenomena, which could be hypothesised to generalise to passenger car driving, were found to determine the ability of four driver models adopted from the literature to fit the human data. Based on the obtained results, it is argued that the concept of internal vehicle models may be less valuable when modelling driver behaviour in non-routine situations such as near-crashes, where behaviour may be better described as direct responses to salient perceptual cues. Some methodological issues in comparing and validating driver models are also discussed.

  16. Driver crash risk factors and prevalence evaluation using naturalistic driving data

    PubMed Central

    Dingus, Thomas A.; Guo, Feng; Lee, Suzie; Antin, Jonathan F.; Perez, Miguel; Buchanan-King, Mindy; Hankey, Jonathan

    2016-01-01

    The accurate evaluation of crash causal factors can provide fundamental information for effective transportation policy, vehicle design, and driver education. Naturalistic driving (ND) data collected with multiple onboard video cameras and sensors provide a unique opportunity to evaluate risk factors during the seconds leading up to a crash. This paper uses a National Academy of Sciences-sponsored ND dataset comprising 905 injurious and property damage crash events, the magnitude of which allows the first direct analysis (to our knowledge) of causal factors using crashes only. The results show that crash causation has shifted dramatically in recent years, with driver-related factors (i.e., error, impairment, fatigue, and distraction) present in almost 90% of crashes. The results also definitively show that distraction is detrimental to driver safety, with handheld electronic devices having high use rates and risk. PMID:26903657

  17. An assessment of the crash fire hazard of liquid hydrogen fueled aircraft

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The crash fire hazards of liquid hydrogen fueled aircraft relative to those of mission equivalent aircraft fueled either with conventional fuel or with liquefied methane were evaluated. The aircraft evaluated were based on Lockheed Corporation design for 400 passenger, Mach 0.85, 5500 n. mile aircraft. Four crash scenarios were considered ranging from a minor incident causing some loss of fuel system integrity to a catastrophic crash. Major tasks included a review of hazardous properties of the alternate fuels and of historic crash fire data; a comparative hazard evluation for each of the three fuels under four crash scenarios a comprehensive review and analysis and an identification of areas further development work. The conclusion was that the crash fire hazards are not significantly different when compared in general for the three fuels, although some fuels showed minor advantages in one respect or another.

  18. Driver crash risk factors and prevalence evaluation using naturalistic driving data.

    PubMed

    Dingus, Thomas A; Guo, Feng; Lee, Suzie; Antin, Jonathan F; Perez, Miguel; Buchanan-King, Mindy; Hankey, Jonathan

    2016-03-01

    The accurate evaluation of crash causal factors can provide fundamental information for effective transportation policy, vehicle design, and driver education. Naturalistic driving (ND) data collected with multiple onboard video cameras and sensors provide a unique opportunity to evaluate risk factors during the seconds leading up to a crash. This paper uses a National Academy of Sciences-sponsored ND dataset comprising 905 injurious and property damage crash events, the magnitude of which allows the first direct analysis (to our knowledge) of causal factors using crashes only. The results show that crash causation has shifted dramatically in recent years, with driver-related factors (i.e., error, impairment, fatigue, and distraction) present in almost 90% of crashes. The results also definitively show that distraction is detrimental to driver safety, with handheld electronic devices having high use rates and risk. PMID:26903657

  19. Driver crash risk factors and prevalence evaluation using naturalistic driving data.

    PubMed

    Dingus, Thomas A; Guo, Feng; Lee, Suzie; Antin, Jonathan F; Perez, Miguel; Buchanan-King, Mindy; Hankey, Jonathan

    2016-03-01

    The accurate evaluation of crash causal factors can provide fundamental information for effective transportation policy, vehicle design, and driver education. Naturalistic driving (ND) data collected with multiple onboard video cameras and sensors provide a unique opportunity to evaluate risk factors during the seconds leading up to a crash. This paper uses a National Academy of Sciences-sponsored ND dataset comprising 905 injurious and property damage crash events, the magnitude of which allows the first direct analysis (to our knowledge) of causal factors using crashes only. The results show that crash causation has shifted dramatically in recent years, with driver-related factors (i.e., error, impairment, fatigue, and distraction) present in almost 90% of crashes. The results also definitively show that distraction is detrimental to driver safety, with handheld electronic devices having high use rates and risk.

  20. An examination of the environmental attributes associated with pedestrian-vehicular crashes near public schools.

    PubMed

    Clifton, Kelly J; Kreamer-Fults, Kandice

    2007-07-01

    This paper examines pedestrian-vehicular crashes in the vicinity of public schools, the severity of injuries sustained, and their relationship to the physical and social attributes near the schools. Multivariate models of crash severity and crash risk exposure were estimated as a function of social and physical characteristics of the area immediately surrounding schools in Baltimore City, Maryland. Results show that the presence of a driveway or turning bay on the school entrance decreases both crash occurrence and injury severity. Conversely, the presence of recreational facilities on the school site is positively associated with crash occurrence and injury severity of crashes. Findings related to neighborhood characteristics were mixed but the significant variables - transit access, commercial access, and population density - are generally associated with increased pedestrian demand and should be interpreted with care. The results of this study are relevant for Safe Routes to School projects and point to areas meriting further study.

  1. Contextualizing Exposures and Experiences of Behaviors That Influence the Risk of Crash Injury in Latino Adolescent Males

    PubMed Central

    Vaca, Federico E.; Trevino, Sandra; Riera, Antonio; Meyer, Emily; Anderson, Craig L.

    2012-01-01

    The largest proportion of mortality burden for U.S. Latino adolescent males is attributed to motor vehicle crashes. In a traffic safety context, relatively little is known about how these youth regularly interface within their own culture and how developmental factors as well as behavior choices influence their risk of crash injury. This complex sociobehavioral interface has implications for how this group perceives, interprets, and navigates the adolescent period that is coupled with passenger and driver experiences. We conducted a mixed method study with triangulation design inclusive of in-depth ethnically concordant interviews. Purposive sampling was used to select Latino adolescent males (15–18 years old). Validated measures of acculturation, sensation and reward seeking, and threat avoidance were administered. Using a standard discussion guide with prompts, we explored respondents’ perceptions of Latino cultural themes, ideas, attitudes, and experiences regarding passenger and driver safety. Codes were created and defined as concepts emerging from the data in an inductive fashion. Using the constant comparative method, we compared coded text to identify novel themes and expand existing themes until thematic saturation was reached. Despite Latino adolescent males expressing a high value of passenger and driver safety, this did not uniformly manifest in their reports of real-life behaviors. Their experiences reflected a dense frequency of exposure to risky behavior modeling and crash injury risk. Opportunities for Latino youth and family-focused risk reduction skill strategies are plentiful. Further research should explore how culture influences parent perceptions of safety and risk and the extent to which family structure shapes the modeling of risk that their adolescent faces. PMID:23169119

  2. Measuring Experiential Avoidance in Adults: The Avoidance and Fusion Questionnaire

    ERIC Educational Resources Information Center

    Schmalz, Jonathan E.; Murrell, Amy R.

    2010-01-01

    To date, general levels of experiential avoidance are primarily measured by the Acceptance and Action Questionnaire-II (AAQ-II), but it includes items of questionable comprehensibility. The Avoidance and Fusion Questionnaire for Youth (AFQ-Y), previously validated as a measure of experiential avoidance with children and adolescents, was…

  3. Dissimilar Teen Crash Rates in Two Neighboring Southeastern Virginia Cities with Different High School Start Times

    PubMed Central

    Vorona, Robert Daniel; Szklo-Coxe, Mariana; Wu, Andrew; Dubik, Michael; Zhao, Yueqin; Ware, J. Catesby

    2011-01-01

    Study Objectives: Early high school start times may contribute to insufficient sleep leading to increased teen crash rate. Virginia Beach (VB) and Chesapeake are adjacent, demographically similar cities. VB high schools start 75-80 minutes earlier than Chesapeake's. We hypothesized that VB teens would manifest a higher crash rate than Chesapeake teens. Methods: The Virginia Department of Motor Vehicles (DMV) provided de-identified, aggregate 2008 and 2007 data for weekday crashes and crash times in VB and Chesapeake for drivers aged 16-18 years (“teens”), and provided 2008 and 2007 crash data for all drivers. Data allowed comparisons of VB versus Chesapeake crash rates for teens (overall and hour-by-hour), and teens versus all other ages. We compared AM and PM traffic congestion (peak hours) in the two cities. Results: In 2008, there were 12,916 and 8,459 Virginia Beach and Chesapeake 16- to 18-year-old drivers, respectively. For VB and Chesapeake, teen drivers' crash rates in 2008 were 65.8/1000 and 46.6/1000 (p < 0.001), respectively, and in 2007 were 71.2/1000 and 55.6/1000. Teen drivers' crash peaks in the morning occurred one hour earlier in VB than Chesapeake, consistent with school commute time. Congestion data for VB and Chesapeake did not explain the different crash rates. Conclusions: A significantly increased teen crash rate for both 2008 and 2007 occurred in VB, the city with earlier high school start times. Future studies using individual level data may clarify if sleep restriction, circadian dyssynchrony, and sleep inertia might contribute to this increased crash rate. Citation: Vorona RD; Szklo-Coxe M; Wu A; Dubik M; Zhao Y; Ware JC. Dissimilar teen crash rates in two neighboring southeastern Virginia cities with different high school start times. J Clin Sleep Med 2011;7(2):145-151. PMID:21509328

  4. Geographic Region, Weather, Pilot Age and Air Carrier Crashes: a Case-Control Study

    PubMed Central

    Li, Guohua; Pressley, Joyce C.; Qiang, Yandong; Grabowski, Jurek G.; Baker, Susan P.; Rebok, George W.

    2009-01-01

    Background Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis and commuter air carriers. Methods A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (n=373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus, recorded in the National Transportation Safety Board’s aviation crash database during 1983 through 2002, and controls (n=746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration’s aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. Results With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions [adjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35 – 7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15 – 4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.57, 95% CI 0.40 – 0.87). Neither pilot age nor total flight time was significantly associated with the risk of air carrier crashes. Conclusions The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety. PMID:19378910

  5. Evaluation of Emergency-Locator-Transmitter performance in real and simulated crash tests

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1981-01-01

    Emergency locator transmitter (ELT) activation problems were investigated by testing a sampling of ELT units in actual crashes and in a special test apparatus which simulated longitudinal crash pulses with superimposed local structural resonances. The probable causes of excessive false alarms and nonactivation of ELT's during crash situations were determined. Solutions to operational and technical problems were also examined as well as the sensitivity of ELT impact switches to orientation and to local structural vibrations.

  6. Crash involvement of large trucks by configuration: a case-control study.

    PubMed Central

    Stein, H S; Jones, I S

    1988-01-01

    For a two-year period, large truck crashes on the interstate system in Washington State were investigated using a case-control method. For each large truck involved in a crash, three trucks were randomly selected for inspection from the traffic stream at the same time and place as the crash but one week later. The effects of truck and driver characteristics on crashes were assessed by comparing their relative frequency among the crash-involved and comparison sample trucks. Double trailer trucks were consistently overinvolved in crashes by a factor of two to three in both single and multiple vehicle crashes. Single unit trucks pulling trailers also were overinvolved. Doubles also had a higher frequency of jackknifing compared to tractor-trailers. The substantial overinvolvement of doubles in crashes was found regardless of driver age, hours of driving, cargo weight, or type of fleet. Younger drivers, long hours of driving, and operating empty trucks were also associated with higher crash involvement. PMID:3354729

  7. Understanding crash mechanism on urban expressways using high-resolution traffic data.

    PubMed

    Hossain, Moinul; Muromachi, Yasunori

    2013-08-01

    Urban expressways play a vital role in the modern mega cities by serving peak hour traffic alongside reducing travel time for moderate to long distance intra-city trips. Thus, ensuring safety on these roads holds high priority. Little knowledge has been acquired till date regarding crash mechanism on these roads. This study uses high-resolution traffic data collected from the detectors to identify factors influencing crash. It also identifies traffic patterns associated with different types of crashes and explains crash phenomena thereby. Unlike most of the previous studies on conventional expressways, the research separately investigates the basic freeway segments (BFS) and the ramp areas. The study employs random multinomial logit, a random forest of logit models, to rank the variables; expectation maximization clustering algorithm to identify crash prone traffic patterns and classification and regression trees to explain crash phenomena. As accentuated by the study outcome, crash mechanism is not generic throughout the expressway and it varies from the BFS to the ramp vicinities. The level of congestion and speed difference between upstream and downstream traffic best explains crashes and their types for the BFS, whereas, the ramp flow has the highest influence in determining the types of crashes within the ramp vicinities. The paper also discusses about the applicability of different countermeasures, such as, variable speed limits, temporary restriction on lane changing, posting warnings, etc., to attenuate different patterns of hazardous traffic conditions. The study outcome can be utilized in designing location and traffic condition specific proactive road safety management systems for urban expressways.

  8. Injury severity data for front and second row passengers in frontal crashes

    PubMed Central

    Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud

    2016-01-01

    The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) for the years 2008–2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief. PMID:27077084

  9. Evaluation of emergency-locator-transmitter performance in real and simulated crash tests

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1981-01-01

    Emergency locator transmitter (ELT) activation problems were investigated by testing a sampling of ELT units in actual airplane crashes and in a special test apparatus which simulated longitudinal crash pulses with superimposed local structural resonances. Probable causes of excessive false alarms and nonactivations of ELT's during crash situations were determined and solutions to the current operational and technical problems were obtained. The results, which considered placement, mounting, and activation of ELT's under simulated crash impacts, and an evaluation of the sensitivity of ELT impact switches to orientation and to local structural vibrations are discussed.

  10. Using Crash Data to Develop Simulator Scenarios for Assessing Novice Driver Performance.

    PubMed

    McDonald, Catherine C; Tanenbaum, Jason B; Lee, Yi-Ching; Fisher, Donald L; Mayhew, Daniel R; Winston, Flaura K

    2012-01-01

    Teenage drivers are at their highest crash risk in their first 6 months or first 1,000 mi of driving. Driver training, adult-supervised practice driving, and other interventions are aimed at improving driving performance in novice drivers. Previous driver training programs have enumerated thousands of scenarios, with each scenario requiring one or more skills. Although there is general agreement about the broad set of skills needed to become a competent driver, there is no consensus set of scenarios and skills to assess whether novice drivers are likely to crash or to assess the effects of novice driver training programs on the likelihood of a crash. The authors propose that a much narrower, common set of scenarios can be used to focus on the high-risk crashes of young drivers. Until recently, it was not possible to identify the detailed set of scenarios that were specific to high-risk crashes. However, an integration of police crash reports from previous research, a number of critical simulator studies, and a nationally representative database of serious teen crashes (the National Motor Vehicle Crash Causation Survey) now make identification of these scenarios possible. In this paper, the authors propose this novel approach and discuss how to create a common set of simulated scenarios and skills to assess novice driver performance and the effects of training and interventions as they relate to high-risk crashes. PMID:23543947

  11. The effects of roadway characteristics on farm equipment crashes: A GIS approach

    NASA Astrophysics Data System (ADS)

    Greenan, Mitchell Joseph

    Tractors and other self-propelled farm equipment, such as combines, sprayers, and towed grain carts, are often used on public roadways as the primary means for traveling from homestead to homestead or from homestead to a distributer. Increased roadway exposure has led to a growing concern for crashes involving farm equipment on the public roadway. A handful of studies exist examining public roadway crashes involving farm equipment using crash data, but none thus far have evaluated road segment data to identify road-specific risk factors. The objective of this study is to identify if roadway characteristics (traffic density, speed limit, road type, surface type, road width, and shoulder width) affect the risk of a crash involving farm equipment on Iowa public roadways. A retrospective cohort study of Iowa roads was conducted to identify the types of roads that are at an increased risk of having a farm-equipment crash on them. Crash data from the Iowa Department of Transportation (to identify crashes) were spatial linked to Iowa roadway data using Geographic Information Systems (GIS). Logistic regression was used to calculate ORs and 95% CL. Out of 319,705 road segments in Iowa, 0.4% segments (n=1,337) had a farm equipment crash from 2005-2011. The odds of having a farm equipment crash were significantly higher for road segments with increased traffic density and speed limit. Roads with an average daily traffic volume of at least 1,251 vehicles were at a 5.53 times greater odds of having a crash than roads with a daily traffic volume between 0-30 vehicles. (CI: 3.90-7.83). Roads with a posted speed limit between 50mph and 60mph were at a 4.88 times greater odds of having a crash than roads with a posted speed limit of 30mph or less. (CI: 3.85-6.20). Specific roadway characteristics such as roadway and shoulder width were also associated with the risk of a crash. For every 5 foot increase in road width, the odds for a crash decreased by 6 percent (CI: 0.89-0.99) and

  12. Aircraft mishap investigation with radiology-assisted autopsy: helicopter crash with control injury.

    PubMed

    Folio, R Les; Harcke, H Theodore; Luzi, Scott A

    2009-04-01

    Radiology-assisted autopsy traditionally has been plain film-based, but now is being augmented by computed tomography (CT). The authors present a two-fatality rotary wing crash scenario illustrating application of advanced radiographic techniques that can guide and supplement the forensic pathologist's physical autopsy. The radiographic findings also have the potential for use by the aircraft mishap investigation board. Prior to forensic autopsy, the two crash fatalities were imaged with conventional two-dimensional radiographs (digital technique) and with multidetector CT The CT data were used for multiplanar two-dimensional and three-dimensional (3D) image reconstruction. The forensic pathologist was provided with information about skeletal fractures, metal fragment location, and other pathologic findings of potential use in the physical autopsy. The radiologic autopsy served as a supplement to the physical autopsy and did not replace the traditional autopsy in these cases. Both individuals sustained severe blunt force trauma with multiple fractures of the skull, face, chest, pelvis, and extremities. Individual fractures differed; however, one individual showed hand and lower extremity injuries similar to those associated with control of the aircraft at the time of impact. The concept of "control injury" has been challenged by Campman et al., who found that control surface injuries have a low sensitivity and specificity for establishing who the pilot was in an accident. The application of new post mortem imaging techniques may help to resolve control injury questions. In addition, the combination of injuries in our cases may contribute to further understanding of control surface injury patterns in helicopter mishaps.

  13. Aircraft mishap investigation with radiology-assisted autopsy: helicopter crash with control injury.

    PubMed

    Folio, R Les; Harcke, H Theodore; Luzi, Scott A

    2009-04-01

    Radiology-assisted autopsy traditionally has been plain film-based, but now is being augmented by computed tomography (CT). The authors present a two-fatality rotary wing crash scenario illustrating application of advanced radiographic techniques that can guide and supplement the forensic pathologist's physical autopsy. The radiographic findings also have the potential for use by the aircraft mishap investigation board. Prior to forensic autopsy, the two crash fatalities were imaged with conventional two-dimensional radiographs (digital technique) and with multidetector CT The CT data were used for multiplanar two-dimensional and three-dimensional (3D) image reconstruction. The forensic pathologist was provided with information about skeletal fractures, metal fragment location, and other pathologic findings of potential use in the physical autopsy. The radiologic autopsy served as a supplement to the physical autopsy and did not replace the traditional autopsy in these cases. Both individuals sustained severe blunt force trauma with multiple fractures of the skull, face, chest, pelvis, and extremities. Individual fractures differed; however, one individual showed hand and lower extremity injuries similar to those associated with control of the aircraft at the time of impact. The concept of "control injury" has been challenged by Campman et al., who found that control surface injuries have a low sensitivity and specificity for establishing who the pilot was in an accident. The application of new post mortem imaging techniques may help to resolve control injury questions. In addition, the combination of injuries in our cases may contribute to further understanding of control surface injury patterns in helicopter mishaps. PMID:19378913

  14. Avoidance of late abortion.

    PubMed

    1979-11-24

    Induced abortion is now a common procedure in the United States and Britain. Methods for performing induced abortion are reviewed. Menstrual regulation, aspiration with a hand-held syringe and a flexible cannula within 6 weeks of the last period, is not often practiced in Britain. Several developing countries are using this simple technique to advantage. Vacuum aspiration in the 1st 12 weeks of pregnancy is the main method being used everywhere for 1st trimester procedures. Mortality rates with this method are low and, in well-organized clinics with experienced personnel, the rates can be reduced even further. It is agreed that 2nd trimester procedures are more complex, both physically and emotionally. In the last several years, dilatation and evacuation (D&E) has increased in popularity for 2nd trimester procedures. Dilation of the cervix is generally accomplished with laminaria, evacuation of the uterus with forceps, and then suction curettage applied. This procedure has replaced intraamniotic infusion, hysterotomy, and hysterectomy as the most commonly - practiced method, despite its need for special surgical skills and good clinical backup. Follow-up of abortions is difficult. Different long-term effects have been noted with different abortion procedures. Early abortion seems to have only a modest effect, if that. Whether late abortion has long-lasting effects remains open to question. Late abortion should be avoided.

  15. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  16. Comparative analysis of PA-31-350 Chieftain (N44LV) accident and NASA crash test data

    NASA Technical Reports Server (NTRS)

    Hayduk, R. J.

    1979-01-01

    A full scale, controlled crash test to simulate the crash of a Piper PA-31-350 Chieftain airplane is described. Comparisons were performed between the simulated crash and the actual crash in order to assess seat and floor behavior, and to estimate the acceleration levels experienced in the craft at the time of impact. Photographs, acceleration histories, and the tested airplane crash data is used to augment the accident information to better define the crash conditions. Measured impact parameters are presented along with flight path velocity and angle in relation to the impact surface.

  17. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production.

    PubMed

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-11-17

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office's (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes.

  18. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production

    PubMed Central

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W.; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office’s (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes. PMID:26593899

  19. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production.

    PubMed

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office's (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes. PMID:26593899

  20. Collision avoidance sensor skin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The objective was to totally eliminate the possibility of a robot (or any mechanism for that matter) inducing a collision in space operations. We were particularly concerned that human beings were safe under all circumstances. This was apparently accomplished, and it is shown that GSFC has a system that is ready for space qualification and flight. However, it soon became apparent that much more could be accomplished with this technology. Payloads could be made invulnerable to collision avoidance and the blind spots behind them eliminated. This could be accomplished by a simple, non-imaging set of 'Capaciflector' sensors on each payload. It also is evident that this system could be used to align and dock the system with a wide margin of safety. Throughout, lighting problems could be ignored, and unexpected events and modeling errors taken in stride. At the same time, computational requirements would be reduced. This can be done in a simple, rugged, reliable manner that will not disturb the form factor of space systems. It will be practical for space applications. The lab experiments indicate we are well on the way to accomplishing this. Still, the research trail goes deeper. It now appears that the sensors can be extended to end effectors to provide precontact information and make robot docking (or any docking connection) very smooth, with minimal loads impacted back into the mating structures. This type of ability would be a major step forward in basic control techniques in space. There are, however, baseline and restructuring issues to be tackled. The payloads must get power and signals to them from the robot or from the astronaut servicing tool. This requires a standard electromechanical interface. Any of several could be used. The GSFC prototype shown in this presentation is a good one. Sensors with their attendant electronics must be added to the payloads, end effectors, and robot arms and integrated into the system.

  1. Changes in Drivers’ Visual Performance during the Collision Avoidance Process as a Function of Different Field of Views at Intersections

    PubMed Central

    Yan, Xuedong; Zhang, Xinran; Zhang, Yuting; Li, Xiaomeng; Yang, Zhuo

    2016-01-01

    The intersection field of view (IFOV) indicates an extent that the visual information can be observed by drivers. It has been found that further enhancing IFOV can significantly improve emergent collision avoidance performance at intersections, such as faster brake reaction time, smaller deceleration rate, and lower traffic crash involvement risk. However, it is not known how IFOV affects drivers’ eye movements, visual attention and the relationship between visual searching and traffic safety. In this study, a driving simulation experiment was conducted to uncover the changes in drivers’ visual performance during the collision avoidance process as a function of different field of views at an intersection by using an eye tracking system. The experimental results showed that drivers’ ability in identifying the potential hazard in terms of visual searching was significantly affected by different IFOV conditions. As the IFOVs increased, drivers had longer gaze duration (GD) and more number of gazes (NG) in the intersection surrounding areas and paid more visual attention to capture critical visual information on the emerging conflict vehicle, thus leading to a better collision avoidance performance and a lower crash risk. It was also found that female drivers had a better visual performance and a lower crash rate than male drivers. From the perspective of drivers’ visual performance, the results strengthened the evidence that further increasing intersection sight distance standards should be encouraged for enhancing traffic safety. PMID:27716824

  2. Development of crash modification factors for changing lane width on roadway segments using generalized nonlinear models.

    PubMed

    Lee, Chris; Abdel-Aty, Mohamed; Park, Juneyoung; Wang, Jung-Han

    2015-03-01

    This study evaluates the effectiveness of changing lane width in reducing crashes on roadway segments. To consider nonlinear relationships between crash rate and lane width, the study develops generalized nonlinear models (GNMs) using 3-years crash records and road geometry data collected for all roadway segments in Florida. The study also estimates various crash modification factors (CMFs) for different ranges of lane width based on the results of the GNMs. It was found that the crash rate was highest for 12-ft lane and lower for the lane width less than or greater than 12ft. GNMs can extrapolate this nonlinear continuous effect of lane width and estimate the CMFs for any lane width, not only selected lane widths, unlike generalized linear models (GLMs) with categorical variables. The CMFs estimated using GNMs reflect that crashes are less likely to occur for narrower lanes if the lane width is less than 12ft whereas crashes are less likely to occur for wider lanes if the lane width is greater than 12ft. However, these effects varied with the posted speed limits as the effect of interaction between lane width and speed limit was significant. The estimated CMFs show that crashes are less likely to occur for lane widths less than 12ft than the lane widths greater than 12ft if the speed limit is higher than or equal to 40mph. It was also found from the CMFs that crashes at higher severity levels (KABC and KAB) are less likely to occur for lane widths greater or less than 12ft compared to 12-ft lane. The study demonstrates that the CMFs estimated using GNMs clearly reflect variations in crashes with lane width, which cannot be captured by the CMFs estimated using GLMs. Thus, it is recommended that if the relationship between crash rate and lane width is nonlinear, the CMFs are estimated using GNMs.

  3. Lower extremity finite element model for crash simulation

    SciTech Connect

    Schauer, D.A.; Perfect, S.A.

    1996-03-01

    A lower extremity model has been developed to study occupant injury mechanisms of the major bones and ligamentous soft tissues resulting from vehicle collisions. The model is based on anatomically correct digitized bone surfaces of the pelvis, femur, patella and the tibia. Many muscles, tendons and ligaments were incrementally added to the basic bone model. We have simulated two types of occupant loading that occur in a crash environment using a non-linear large deformation finite element code. The modeling approach assumed that the leg was passive during its response to the excitation, that is, no active muscular contraction and therefore no active change in limb stiffness. The approach recognized that the most important contributions of the muscles to the lower extremity response are their ability to define and modify the impedance of the limb. When nonlinear material behavior in a component of the leg model was deemed important to response, a nonlinear constitutive model was incorporated. The accuracy of these assumptions can be verified only through a review of analysis results and careful comparison with test data. As currently defined, the model meets the objective for which it was created. Much work remains to be done, both from modeling and analysis perspectives, before the model can be considered complete. The model implements a modeling philosophy that can accurately capture both kinematic and kinetic response of the lower limb. We have demonstrated that the lower extremity model is a valuable tool for understanding the injury processes and mechanisms. We are now in a position to extend the computer simulation to investigate the clinical fracture patterns observed in actual crashes. Additional experience with this model will enable us to make a statement on what measures are needed to significantly reduce lower extremity injuries in vehicle crashes. 6 refs.

  4. Degree of Urbanization and Mortality From Motor Vehicular Crashes

    PubMed Central

    Ryb, Gabriel E; Dischinger, Patricia C; McGwin, Gerald; Griffin, Russell L

    2012-01-01

    Purpose: The purpose of this study is to establish whether motor vehicular crash (MVC) case fatality varies across different urbanization levels in the USA using a representative sample of crashes. Methods: Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between urbanization level [i.e., central city (CC), suburban (SU) and others (OT)] and mortality were estimated in the 1997 - 2010 National Automotive Sampling System Crashworthiness Data System. Multiple logistic regression was used to adjust for confounders. Analysis was repeated for the occurrence of pre-hospital and hospital deaths. Results: 49,040,520 weighted occupants were included in the study. The distribution of occupants by urbanization categories was: SU 45%, OT 42%, and CC 13%. Case fatality was higher among OT occupants (0.81%) than among SU (0.51%) and CC (0.37%) occupants. Similar findings were present for pre-hospital deaths (OT 0.52%, SU 0.30%, and CC 0.21%) and hospital deaths (OT 0.29%, SU 0.21%, and CC 0.16%). Multivariate analysis revealed that adjusted odds of death were higher for OT cases [OR=1.55 (1.05–2.30)] than the CC. Adjusted odds of death for SU (OR=1.05 (0.81–1.37) were not different than CCs. Similar but accentuated findings were found for pre-hospital deaths. In contrast, adjusted odds of hospital death were not different among the 3 groups. Conclusion: Occupants of vehicles crashing in OT (i.e., rural areas and small cities) experience a higher likelihood of dying after MVCs than those in CC and SU. Pre-hospital deaths, not hospital deaths, are responsible for this disparity. PMID:23169128

  5. Commuter motorcycle crashes in Malaysia: An understanding of contributing factors

    PubMed Central

    Oxley, Jennifer; Yuen, Jeremy; Ravi, Mano Deepa; Hoareau, Effie; Mohammed, Mohammed Azman Aziz; Bakar, Harun; Venkataraman, Saraswathy; Nair, Prame Kumar

    2013-01-01

    In Malaysia, two-thirds of reported workplace-related fatal and serious injury incidents are the result of commuting crashes (especially those involving motorcyclists), however, little is known about the contributing factors to these collisions. A telephone survey of 1,750 motorcyclists (1,004 adults who had been involved in a motorcycle commuting crash in the last 2 years and 746 adult motorcyclists who had not been involved in a motorcycle crash in the last 2 years) was undertaken. The contributions of a range of behavioural, attitudinal, employment and travel pattern factors to collision involvement were examined. The findings revealed that the majority of participants were licensed riders, rode substantial distances (most often for work purposes), and reported adopting safe riding practices (helmet wearing and buckling). However, there were some concerning findings regarding speeding behaviour, use of mobile phones while riding, and engaging in other risky behaviours. Participants who had been involved in a collision were younger (aged 25–29 years), had higher exposure (measured by distances travelled, frequency of riding, and riding on high volume and higher speed roads), reported higher rates of riding for work purposes, worked more shift hours and had a higher likelihood of riding at relatively high speeds compared with participants who had not been involved in a collision. Collisions generally occurred during morning and early evening hours, striking another vehicles, and during normal traffic flow. The implications of these findings for policy decisions and development of evidence-based behavioural/training interventions addressing key contributing factors are discussed. PMID:24406945

  6. Crash-Energy Absorbing Composite Structure and Method of Fabrication

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris (Inventor); Carden, Huey D. (Inventor)

    1998-01-01

    A stand-alone, crash-energy absorbing structure and fabrication method are provided. A plurality of adjoining rigid cells are each constructed of resin-cured fiber reinforcement and are arranged in a geometric configuration. The geometric configuration of cells is integrated by means of continuous fibers wrapped thereabout in order to maintain the cells in the geometric configuration. The cured part results in a net shape, stable structure that can function on its own with no additional reinforcement and can withstand combined loading while crushing in a desired direction.

  7. Epidemiology of Child Motor Vehicle Crash Injuries and Fatalities

    NASA Astrophysics Data System (ADS)

    Arbogast, Kristy B.; Durbin, Dennis R.

    Although children represent only 10-15 % of the overall traffic fatality burden in the United States, motor vehicle crashes (MVCs) remain the leading cause of death and disability for children and young adults; and, close to half of all unintentional injury deaths to children and adolescents (Centers for Disease Control and Prevention National Center for Injury Prevention and Control, Web-based Injury Statistics Query and Reporting System [CDC NCIPC WISQARS] 2010). Moreover, their exposure to motor vehicle risk is significant because they travel by motor vehicles nearly as much as adults. Prevention of the fatalities, injuries and disability associated with MVC must be a priority for ensuring our children's overall health.

  8. The Purley train crash mechanism: injuries and prevention.

    PubMed Central

    Fothergill, N J; Ebbs, S R; Reese, A; Partridge, R J; Mowbray, M; Southcott, R D; Hashemi, K

    1992-01-01

    On the afternoon of Saturday 4th March 1989 two trains, both bound for London Victoria Station, collided. Part of the rear train rolled down a steep railway embankment and jack-knifed against a tree. The mechanism of the crash and the injuries sustained by the 55 victims who were seen in the A&E Department of the Mayday University Hospital are described. Improvements in signalling technology and design of rolling stock which may reduce both the risk of collision and severity of injury in future accidents are discussed. Images Fig. 1 PMID:1388485

  9. Initiative for safe driving and enhanced utilization of crash data

    NASA Astrophysics Data System (ADS)

    Wagner, John F.

    1994-03-01

    This initiative addresses the utilization of current technology to increase the efficiency of police officers to complete required Driving Under the Influence (DUI) forms and to enhance their ability to acquire and record crash and accident information. The project is a cooperative program among the New Mexico Alliance for Transportation Research (ATR), Science Applications International Corporation (SAIC), Los Alamos National Laboratory, and the New Mexico State Highway and Transportation Department. The approach utilizes an in-car computer and associated sensors for information acquisition and recording. Los Alamos artificial intelligence technology is leveraged to ensure ease of data entry and use.

  10. Development of a low-cost crash cushion using recycled automobile tires. Final report

    SciTech Connect

    Habors, D.T.; Hossain, M.

    1998-09-01

    Approximately thirty percent of all vehicle related fatalities that occur each year caused by a single vehicle leaving the road and striking a fixed object; the most common objects struck being trees, guardrails, and utility poles. In many cases current crash cushion systems are not cost effective to be installed on such obstacles. In addition to high initial costs many crash cushions require extensive maintenance or expensive replacement parts driving costs up even more. This makes the development of a more cost-effective crash cushion a necessity. This study proposed an initial design for a low-cost, reusable crash cushion using recycled materials. Used tires and tire-derived materials were tested in both static and dynamic modes to evaluate their application in a crash cushion. Both proved to be able to sustain high loads and durable, making them good candidates for use in a crash cushion. However, the tire-derived pads had excessively high loads per unit deflection prohibiting their use in a crash cushion. This problem could be eliminated if voids were added to allow material to deflect more under loading. The used tires could be used effectively as energy absorbing elements in crash cushions or truck mounted attenuators (TMA`s) if compressed horizontally or vertically.

  11. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    PubMed

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-06-18

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling.

  12. "Crash": Using a Popular Film as an Experiential Learning Activity in a Multicultural Counseling Course

    ERIC Educational Resources Information Center

    Villalba, Jose A.; Redmond, Rachelle E.

    2008-01-01

    "Crash" (P. Haggis, 2004) depicts the intersection of race, ethnicity, religion, and social class in a culturally and politically charged environment. The result is a film that places the viewer in situations that are void of simple right and wrong solutions. The authors describe an experiential learning activity that is based on using "Crash" to…

  13. 78 FR 53386 - Federal Motor Vehicle Safety Standards; Occupant Crash Protection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... 20 mph to 25 mph rigid barrier crash test (65 FR 30680). \\11\\ On September 2, 1993, NHTSA amended... considering unbelted crash test requirements date back to the 1970s (35 FR 16927).\\14\\ To do so without a...-seat occupant was not buckled up (37 FR 3911). However, as a result of consumer non-acceptance of...

  14. Symposium: "Crash": Rhetorically Wrecking Discourses of Race, Tolerance, and White Privilege

    ERIC Educational Resources Information Center

    Nunley, Vorris L.

    2007-01-01

    From within the milieu of race and identity fatigue emerges "Crash." Winner of three Academy Awards, including Best Picture, "Crash" addresses how the fluidity of identity is pooled, ebbed, blocked, directed, dammed up. How identity and subjectivity are dammed up and mediated through the force of the anxieties, fears, and frustrations of people…

  15. The Civil Rights Movement According to "Crash": Complicating the Pedagogy of Integration

    ERIC Educational Resources Information Center

    Holmes, David G.

    2007-01-01

    In this article, the author talks about a critically acclaimed movie "Crash" and what it reveals pedagogically about the paradoxical legacies of the grand experiment in radical democracy. Written and directed by Paul Haggis, "Crash" inundates the viewer with a barrage of the most condescending racial and ethnic insults, which peak curiously toward…

  16. Influence of horizontally curved roadway section characteristics on motorcycle-to-barrier crash frequency.

    PubMed

    Gabauer, Douglas J; Li, Xiaolong

    2015-04-01

    The purpose of this study was to investigate motorcycle-to-barrier crash frequency on horizontally curved roadway sections in Washington State using police-reported crash data linked with roadway data and augmented with barrier presence information. Data included 4915 horizontal curved roadway sections with 252 of these sections experiencing 329 motorcycle-to-barrier crashes between 2002 and 2011. Negative binomial regression was used to predict motorcycle-to-barrier crash frequency using horizontal curvature and other roadway characteristics. Based on the model results, the strongest predictor of crash frequency was found to be curve radius. This supports a motorcycle-to-barrier crash countermeasure placement criterion based, at the very least, on horizontal curve radius. With respect to the existing horizontal curve criterion of 820 feet or less, curves meeting this criterion were found to increase motorcycle-to-barrier crash frequency rate by a factor of 10 compared to curves not meeting this criterion. Other statistically significant predictors were curve length, traffic volume and the location of adjacent curves. Assuming curves of identical radius, the model results suggest that longer curves, those with higher traffic volume, and those that have no adjacent curved sections within 300 feet of either curve end would likely be better candidates for a motorcycle-to-barrier crash countermeasure.

  17. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    PubMed

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-01-01

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling. PMID:27322306

  18. Comparison of Test and Finite Element Analysis for Two Full-Scale Helicopter Crash Tests

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Horta,Lucas G.

    2011-01-01

    Finite element analyses have been performed for two full-scale crash tests of an MD-500 helicopter. The first crash test was conducted to evaluate the performance of a composite deployable energy absorber under combined flight loads. In the second crash test, the energy absorber was removed to establish the baseline loads. The use of an energy absorbing device reduced the impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to analytical results. Details of the full-scale crash tests and development of the system-integrated finite element model are briefly described along with direct comparisons of acceleration magnitudes and durations for the first full-scale crash test. Because load levels were significantly different between tests, models developed for the purposes of predicting the overall system response with external energy absorbers were not adequate under more severe conditions seen in the second crash test. Relative error comparisons were inadequate to guide model calibration. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used for the second full-scale crash test. The calibrated parameter set reduced 2-norm prediction error by 51% but did not improve impact shape orthogonality.

  19. Bicycle Guidelines and Crash Rates on Cycle Tracks in the United States

    PubMed Central

    Morency, Patrick; Miranda-Moreno, Luis F.; Willett, Walter C.; Dennerlein, Jack T.

    2013-01-01

    Objectives. We studied state-adopted bicycle guidelines to determine whether cycle tracks (physically separated, bicycle-exclusive paths adjacent to sidewalks) were recommended, whether they were built, and their crash rate. Methods. We analyzed and compared US bicycle facility guidelines published between 1972 and 1999. We identified 19 cycle tracks in the United States and collected extensive data on cycle track design, usage, and crash history from local communities. We used bicycle counts and crash data to estimate crash rates. Results. A bicycle facility guideline written in 1972 endorsed cycle tracks but American Association of State Highway and Transportation Officials (AASHTO) guidelines (1974–1999) discouraged or did not include cycle tracks and did not cite research about crash rates on cycle tracks. For the 19 US cycle tracks we examined, the overall crash rate was 2.3 (95% confidence interval = 1.7, 3.0) per 1 million bicycle kilometers. Conclusions. AASHTO bicycle guidelines are not explicitly based on rigorous or up-to-date research. Our results show that the risk of bicycle–vehicle crashes is lower on US cycle tracks than published crashes rates on roadways. This study and previous investigations support building cycle tracks. PMID:23678920

  20. Injuries to deployed U.S. Army soldiers involved in HMMWV crashes, 2002-2006.

    PubMed

    Peik, Samuel M; Pollack, Keshia M; Canham-Chervak, Michelle; Hauret, Keith G; Baker, Susan P

    2012-08-01

    Highly mobile multipurpose wheeled vehicle (HMMWV or Humvee) crashes present an important issue for the U.S. military. The aim of this study was to provide a descriptive analysis of occupants of military motor vehicle (MMV) crashes involving HMMWVs that occurred among deployed U.S. Army Soldiers. Crash-related data were collected from the U.S. Army Combat Readiness/Safety Center on MMV crashes among active duty Army personnel between 1999 and 2006. Records for 964 occupants with injuries from HMMWV crashes were analyzed, which represented 52% of the total occupants of MMV crashes. A significant association was observed between injury and engagement in combat, odds ratio 1.49 (1.03, 2.16). The risk of injury was greatest for gunners, odds ratio 2.37 (1.43, 3.92), and injury cost related to the crash was significantly related to prior deployment status (p < 0.001) and role of Soldier in the vehicle (Operator p = 0.005, Gunner p = 0.003). There was also a decrease over time in the number of crashes resulting in injury (p < 0.001). These data support the development of interventions that address the specific risks detailed, including the use of combat simulation training, increased protection for vulnerable positions, and enforcement of safety regulations. PMID:22934378

  1. 76 FR 46359 - Announcing the Nineteenth Public Meeting of the Crash Injury Research and Engineering Network...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... centers to enroll crash victims into the CIREN program. Engineering teams are led by mechanical engineers... Research and Engineering Network (CIREN) AGENCY: National Highway Traffic Safety Administration (NHTSA... members of the Crash Injury Research and Engineering Network. CIREN is a collaborative effort to...

  2. Crash Analysis of Automotive Chassis Structure Considering the Strain Hardening Effect

    NASA Astrophysics Data System (ADS)

    Mashalkar, A. S.; Parvekar, R. P.

    2011-08-01

    The work hardening during the forming process is generally ignored in crash analysis. This paper presents computational details of the effect of forming process on crash response of typical Sports Utility Vehicles (SUV). Forming results for front panels of a medium-sized SUV were calculated using Hyperform and LS Dyna. These were imported into the crash model and crash results compared with and without the forming effects. Time taken to generate the forming data by a variety of methods is quantified and the trade-off between time taken and accuracy is examined. LS-DYNA was used for both forming and crash simulations. The effect of thickness, work hardening and residual stresses on the crashworthiness results is measured; crash response is seen to be significantly affected when the effects of forming are included. The paper proposes a systematic method to transfer data from the forming analysis to crashworthiness analysis (both using LS-DYNA), allowing thickness, residual stress and plastic strain data selectively or in combination to be used to initialise the crash model. The relative effect of each of these forming parameters has been examined and the importance of, work hardening on the crash response of the stamping front rail has been identified. A significant change in energy absorption, peak force and stroke of the front rail was predicted, indicating a far stiffer response in the formed rail than would be expected based on the nominal material properties. Therefore, forming effects should be accounted for in vehicle crashworthiness predictions.

  3. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models

    PubMed Central

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-01-01

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling. PMID:27322306

  4. A random parameters probit model of urban and rural intersection crashes.

    PubMed

    Tay, Richard

    2015-11-01

    Intersections are hazardous locations and many studies have been conducted to identify the factors contributing to the frequency and severity of intersection crashes. However, little attention has been devoted to investigating the differences between crashes at urban and rural intersections, which have different road, traffic and environmental characteristics. By applying a random parameters probit model to the data from the Canadian Province of Alberta between 2008 and 2012, we find that urban intersection crashes are more likely to be associated with hit and run behaviours, roads with higher traffic volume, wet surfaces, four lanes and skewed intersections, and crashes on weekdays and off-peak hours, whereas rural crashes are likely to be associated with increases in fatalities and injuries, roads with higher speed limits, special road features, exit and entrance terminals, gravel, curvature and two lanes, crashes during weekends, peak hours and night-time, run-off-road crashes, and police visit to crash scene. Hence, road safety professionals in urban and rural areas should consider these differences when designing and implementing counter-measures to improve intersection safety, especially their safety audits and reviews, enforcement activities and education campaigns, to target the more vulnerable times and locations in the different areas.

  5. Exciting New Take on a Classic: Crash Test Activity Puts the Egg in the Driver's Seat

    ERIC Educational Resources Information Center

    Board, Keith

    2011-01-01

    An excellent common activity in technology and engineering classes involves dropping an egg from a significant height in a protective device designed and built by students. This article describes how the author uses the classic "egg drop" as an inspiration to have students modify a small crash test vehicle that speeds down a track and crashes into…

  6. Exciting New Take on a Classic: Crash Testing Activity Puts the Egg in the Driver's Seat

    ERIC Educational Resources Information Center

    Board, Keith

    2011-01-01

    An excellent common activity in technology and engineering classes involves dropping an egg from a significant height in a protective device designed and built by students. This article describes how the author uses the classic "egg drop" as an inspiration to have students modify a small crash test vehicle that speeds down a track and crashes into…

  7. Cervical and thoracic spine injury from interactions with vehicle roofs in pure rollover crashes.

    PubMed

    Bambach, M R; Grzebieta, R H; McIntosh, A S; Mattos, G A

    2013-01-01

    Around one third of serious injuries sustained by belted, non-ejected occupants in pure rollover crashes occur to the spine. Dynamic rollover crash test methodologies have been established in Australia and the United States, with the aims of understanding injury potential in rollovers and establishing the basis of an occupant rollover protection crashworthiness test protocol that could be adopted by consumer new car assessment programmes and government regulators internationally. However, for any proposed test protocol to be effective in reducing the high trauma burden resulting from rollover crashes, appropriate anthropomorphic devices that replicate real-world injury mechanisms and biomechanical loads are required. To date, consensus regarding the combination of anthropomorphic device and neck injury criteria for rollover crash tests has not been reached. The aim of the present study is to provide new information pertaining to the nature and mechanisms of spine injury in pure rollover crashes, and to assist in the assessment of spine injury potential in rollover crash tests. Real-world spine injury cases that resulted from pure rollover crashes in the United States between 2000 and 2009 are identified, and compared with cadaver experiments under vertical load by other authors. The analysis is restricted to contained, restrained occupants that were injured from contact with the vehicle roof structure during a pure rollover, and the role of roof intrusion in creating potential for spine injury is assessed. Recommendations for assessing the potential for spine injury in rollover occupant protection crash test protocols are made. PMID:23149322

  8. Assessment of aircraft crash frequency for the Hanford site 200 Area tank farms

    SciTech Connect

    OBERG, B.D.

    2003-03-22

    Two factors, the near-airport crash frequency and the non-airport crash frequency, enter into the estimate of the annual aircraft crash frequency at a facility. The near-airport activities, Le., takeoffs and landings from any of the airports in a 23-statute-mile (smi) (20-nautical-mile, [nmi]) radius of the facilities, do not significantly contribute to the annual aircraft crash frequency for the 200 Area tank farms. However, using the methods of DOE-STD-3014-96, the total frequency of an aircraft crash for the 200 Area tank farms, all from non-airport operations, is calculated to be 7.10E-6/yr. Thus, DOE-STD-3014-96 requires a consequence analysis for aircraft crash. This total frequency consists of contributions from general aviation, helicopter activities, commercial air carriers and air taxis, and from large and small military aircraft. The major contribution to this total is from general aviation with a frequency of 6.77E-6/yr. All other types of aircraft have less than 1E-6/yr crash frequencies. The two individual aboveground facilities were in the realm of 1E-7/yr crash frequencies: 204-AR Waste Unloading Facility at 1.56E-7, and 242-T Evaporator at 8.62E-8. DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', states that external events, such as aircraft crashes, are referred to as design basis accidents (DBA) and analyzed as such: ''if frequency of occurrence is estimated to exceed 10{sup -6}/yr conservatively calculated'' DOE-STD-3014-96 considers its method for estimating aircraft crash frequency as being conservative. Therefore, DOE-STD-3009-94 requires DBA analysis of an aircraft crash into the 200 Area tank farms. DOE-STD-3009-94 also states that beyond-DBAs are not evaluated for external events. Thus, it requires only a DBA analysis of the effects of an aircraft crash into the 200 Area tank farms. There are two attributes of an aircraft crash into a Hanford waste storage tank

  9. Estimating costs of traffic crashes and crime: tools for informed decision making.

    PubMed

    Streff, F M; Molnar, L J; Cohen, M A; Miller, T R; Rossman, S B

    1992-01-01

    Traffic crashes and crime both impose significant economic and social burdens through injury and loss of life, as well as property damage and loss. Efforts to reduce crashes and crime often result in competing demands on limited public resources. Comparable and up-to-date cost data on crashes and crime contribute to informed decisions about allocation of these resources in important ways. As a first step, cost data provide information about the magnitude of the problems of crashes and crime by allowing us to estimate associated dollar losses to society. More importantly, cost data on crashes and crime are essential to evaluating costs and benefits of various policy alternatives that compete for resources. This paper presents the first comparable comprehensive cost estimates for crashes and crime and applies them to crash and crime incidence data for Michigan to generate dollar losses for the state. An example illustrates how cost estimates can be used to evaluate costs and benefits of crash-reduction and crime-reduction policies in making resource allocation decisions. Traffic crash and selected index crime incidence data from the calendar year 1988 were obtained from the Michigan State Police. Costs for crashes and index crimes were generated and applied to incidence data to estimate dollar losses from crashes and index crimes for the state of Michigan. In 1988, index crimes in Michigan resulted in $0.8 billion in monetary costs and $2.4 billion in total monetary and nonmonetary quality-of-life costs (using the willingness-to-pay approach). Traffic crashes in Michigan resulted in $2.3 billion in monetary costs and $7.1 billion in total monetary and nonmonetary quality-of-life costs, nearly three times the costs of index crimes. Based on dollar losses to the state, the magnitude of the problem of traffic crashes clearly exceeded that of index crimes in Michigan in 1988. From a policy perspective, summing the total dollar losses from crashes or crime is of less

  10. Coupled simulation of kinetic pedestal growth and MHD ELM crash

    SciTech Connect

    Park, G-Y; Cummings, J.; Chang, C S; Podhorszki, Norbert; Klasky, Scott A; Ku, S.; Pankin, A.; Samtaney, Ravi; Shoshani, A.; Snyder, P.; Sugiyama, L.

    2009-01-01

    Edge pedestal height and the accompanying ELM crash are critical elements of ITER physics yet to be understood and predicted through high performance computing. An entirely self-consistent first principles simulation is being pursued as a long term research goal, and the plan is planned for completion in time for ITER operation. However, a proof-of-principle work has already been established using a computational tool that employs the best first principles physics available at the present time. A kinetic edge equilibrium code XGC0, which can simulate the neoclassically dominant pedestal growth from neutral ionization (using a phenomenological residual turbulence diffusion motion superposed upon the neoclassical particle motion) is coupled to an extended MHD code M3D, which can perform the nonlinear ELM crash. The stability boundary of the pedestal is checked by an ideal MHD linear peeling-ballooning code, which has been validated against many experimental data sets for the large scale (type I) ELMs onset boundary. The coupling workflow and scientific results to be enabled by it are described.

  11. Coupled simulation of kinetic pedestal growth and MHD ELM crash

    SciTech Connect

    Park, G.; Cummings, J.; Chang, C. S.; Klasky, Scott A; Ku, S.; Podhorszki, Norbert; Pankin, A.; Samtaney, Ravi; Shoshani, A.; Snyder, P.; Strauss, H.; Sugiyama, L.; CPES Team, the

    2007-01-01

    Edge pedestal height and the accompanying ELM crash are critical elements of ITER physics yet to be understood and predicted through high performance computing. An entirely self-consistent first principles simulation is being pursued as a long term research goal, and the plan is planned for completion in time for ITER operation. However, a proof-of-principle work has already been established using a computational tool that employs the best first principles physics available at the present time. A kinetic edge equilibrium code XGC0, which can simulate the neoclassically dominant pedestal growth from neutral ionization (using a phenomenological residual turbulence diffusion motion superposed upon the neoclassical particle motion) is coupled to an extended MHD code M3D, which can perform the nonlinear ELM crash. The stability boundary of the pedestal is checked by an ideal MHD linear peeling-ballooning code, which has been validated against many experimental data sets for the large scale (type I) ELMs onset boundary. The coupling workflow and scientific results to be enabled by it are described.

  12. Large reductions are possible in older driver crashes at intersections.

    PubMed

    Samuel, Siby; Yamani, Yusuke; Fisher, Donald L

    2016-09-01

    Among all crash types, the largest percentage of older driver fatalities occur at intersections. Many explanations have been offered for older drivers' increased risks of crashing at intersections; however, only recently was it determined that older drivers were much less likely to glance for latent threats after entering an intersection than middle-aged drivers. In response, training programmes were designed to increase the frequency of such glances. The programmes have proven effective, doubling the frequency of these glances for up to a period of two years post-training. The programmes take only an hour to administer and are not directly targeted at remediating any of the underlying declines in cognitive, visual or motor function that can explain the decrease in the frequency of glances for threat vehicles among older drivers. The first question we addressed was, what are the basic declines that can explain the decrease in glances for threat vehicles? The second question we addressed was, how did the training programme achieve the results it did without directly addressing these declines? We hypothesise that drivers are learning to decouple hand, foot and head movements in the training programmes and that this serialisation of behaviour essentially sidesteps the major declines in cognitive, visual and motor functions. We provide evidence that the assumptions of the decoupling hypothesis about the capabilities of older drivers when the movements are decoupled, are consistent with the evidence from existing experiments. More research is needed to evaluate this hypothesis. PMID:27523785

  13. Crash simulation of UNS electric vehicle under frontal front impact

    NASA Astrophysics Data System (ADS)

    Susilo, D. D.; Lukamana, N. I.; Budiana, E. P.; Tjahjana, D. D. D. P.

    2016-03-01

    Sebelas Maret University has been developing an Electric Vehicle namely SmarT-EV UNS. The main structure of the car are chasis and body. The chasis is made from steel and the body is made from fiberglass composite. To ensure the safety of the car, both static and dynamic tests were carried out to these structures, including their materials, like: tensile test, bending test, and impact test. Another test needed by this vehicle is crashworthiness test. To perform the test, it is needed complex equipments and it is quite expensive. Another way to obtain vehicle crashworthiness behaviour is by simulate it. The purpose of this study was to simulate the response of the Smart-EV UNS electric vehicle main structure when crashing rigid barrier from the front. The crash simulation was done in according to the NHTSA (National Highway Traffic Safety Administration) within the speed of the vehicle of 35 mph. The UNS Electric Vehicle was modelled using SolidWorks software, and the simulation process was done by finite element method using ANSYS software. The simulation result showed that the most internal impact energy was absorbed by chassis part. It absorbed 76.2% of impact energy, then the base absorbed 11.3 %, while the front body absorbed 2.5 %, and the rest was absorbed by fender, hood, and other parts.

  14. Farm Equipment-Motor Vehicle Crash Prevention Conference (FEMVCPC).

    PubMed

    Petrea, Robert E; Madsen, Murray D

    2010-04-01

    This plenary talk at the eighth annual Midwest Rural Agricultural Safety and Health Forum, November 2009, described a conference held earlier in the year focusing on the hazards and risks associated with moving agricultural equipment on public roads. The Farm Equipment-Motor Vehicle Crash Prevention Conference (FEMVCPC), March 2009, Des Moines, Iowa, drew 54 participants representing 13 states for presentations and discussions. Data showing that over 1100 farm equipment-motor vehicle crashes occur annually in the Great Plains Center for Agricultural Health's nine-state region document agricultural producer stated concerns. The conference format allowed for presentations from a wide range of perspectives and provided discussion time for caucusing at two levels. The first level involved caucus by specialty (e.g., state agencies, sheriff/highway patrol, driver educators, farmers, retailers/manufacturers). The second level caucuses gathered individuals from their respective states to consider what is being done and what could be done relative to each area identified in the first level caucuses. The final product of the conference was a specific action plan each state group would advocate and bring forward in their state. On-site and 6-month follow-up evaluations with each state group indicated that the conference content increased participant knowledge and provided them with new content to use in current and future state programs. As important is the finding that participants have used conference content to foster interest, new collaborations, and specific project planning related to agricultural roadway transportation issues.

  15. Rhabdomyolysis and unilateral renal infarction after a motor vehicle crash.

    PubMed

    Sanai, Toru; Yokoyama, Masaaki; Murata, Akinari; Ukon, Kei; Fuchigami, Kazumi

    2007-01-01

    A 46-year-old man with no previous history of abnormal urinalysis findings or renal dysfunction was admitted to a local hospital because of a motor vehicle crash. An open laparotomy was performed to treat a perforation of the small intestine. After operation, oliguria and renal dysfunction developed, and he was admitted to our hospital because of acute renal failure after trauma. Acute renal failure was assumed to be due to rhabdomyolysis with elevated serum creatinine, blood urea nitrogen, and creatine kinase levels and myoglobinemia. Left flank pain occurred several days after admission, and the serum alkaline phosphatase level increased between days 5 and 12 following admission. Although hemodialysis was performed 9 times and the urine output was satisfactory, the creatinine clearance levels increased only to about 50 mL/min/1.73 m2 (0.84 mL/s/m2) at 6 weeks following admission. As a result, a diagnosis of renal infarction due to acute renal artery occlusion was considered. The left kidney was atrophic on an abdominal computed tomographic scan and was nonfunctioning on a renogram. This case shows the importance of not overlooking the possibility of a renal infarction associated with rhabdomyolysis after a motor vehicle crash. In particular, the changes in the serum alkaline phosphatase levels were important in making a correct diagnosis in this case.

  16. Crash Simulator: Brain-and-Spine Injury Mechanics

    NASA Astrophysics Data System (ADS)

    Ivancevic, Vladimir G.; Reid, Darryn J.

    2015-11-01

    Recently, the first author has proposed a new coupled loading-rate hypothesis as a unique cause of both brain and spinal injuries, which states that they are both caused by a Euclidean jolt, an impulsive loading that strikes head and spine (or, any other part of the human body)- in several coupled degrees-of-freedom simultaneously. Injury never happens in a single direction only, nor is it ever caused by a static force. It is always an impulsive translational plus rotational force. The Euclidean jolt causes two basic forms of brain, spine and other musculo-skeletal injuries: (i) localized translational dislocations; and (ii) localized rotational disclinations. In the present Chapter, we first review this unique mechanics of a general human mechanical injury, and then describe how it can be predicted and controlled by a crash simulator toolbox. This rigorous Matlab toolbox has been developed using an existing thirdparty toolbox DiffMan, for accurately solving differential equations on smooth manifolds and mechanical Lie groups. The present crash simulator toolbox performs prediction/control of brain and spinal injuries within the framework of the Euclidean group SE(3) of rigid motions in our natural 3-dimensional space.

  17. Stimulus conflict triggers behavioral avoidance.

    PubMed

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

  18. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk.

  19. Stimulus conflict triggers behavioral avoidance.

    PubMed

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance. PMID:25931151

  20. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk. PMID:18758277

  1. Effect of crash pulse shape on seat stroke requirements for limiting loads on occupants of aircraft

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.

    1992-01-01

    An analytical study was made to provide comparative information on various crash pulse shapes that potentially could be used to test seats under conditions included in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats, show the effects that crash pulse shape can have on the seat stroke requirements necessary to maintain a specified limit loading on the seat/occupant during crash pulse loadings, compare results from certain analytical model pulses with approximations of actual crash pulses, and compare analytical seat results with experimental airplace crash data. Structural and seat/occupant displacement equations in terms of the maximum deceleration, velocity change, limit seat pan load, and pulse time for five potentially useful pulse shapes were derived; from these, analytical seat stroke data were obtained for conditions as specified in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats.

  2. Analysis of Firetruck Crashes and Associated Firefighter Injuries in the United States

    PubMed Central

    Donoughe, Kelly; Whitestone, Jennifer; Gabler, Hampton C.

    2012-01-01

    Motor vehicle crashes are the second leading cause of death for on-duty firefighters. Firetruck crashes, occurring at a rate of approximately 30,000 crashes per year, have potentially dire consequences for the vehicle occupants and for the community if the firetruck was traveling to provide emergency services. Data from the United States Fire Administration and the National Highway Traffic Safety Administration shows that firefighters neglect to buckle their seatbelts while traveling in a fire apparatus, thus putting themselves at a high risk for injuries if the truck crashes, especially in rollover crashes. Despite national regulations and departmental guidelines aiming to improve safety on fire apparatuses, belt use among firefighters remains dangerously low. The results from this study indicate that further steps need to be taken to improve belt use. One promising solution would be to redesign firetruck seatbelts to improve the ease of buckling and to accommodate wider variations in firefighter sizes. PMID:23169118

  3. Effect of perception irregularity on chain-reaction crash in low visibility

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2015-06-01

    We present the dynamic model of the chain-reaction crash to take into account the irregularity of the perception-reaction time. When a driver brakes according to taillights of the forward vehicle, the perception-reaction time varies from driver to driver. We study the effect of the perception irregularity on the chain-reaction crash (multiple-vehicle collision) in low-visibility condition. The first crash may induce more collisions. We investigate how the first collision induces the chain-reaction crash numerically. We derive, analytically, the transition points and the region maps for the chain-reaction crash in traffic flow of vehicles with irregular perception times. We clarify the effect of the perception irregularity on the multiple-vehicle collision.

  4. Analysis of firetruck crashes and associated firefighter injuries in the United States.

    PubMed

    Donoughe, Kelly; Whitestone, Jennifer; Gabler, Hampton C

    2012-01-01

    Motor vehicle crashes are the second leading cause of death for on-duty firefighters. Firetruck crashes, occurring at a rate of approximately 30,000 crashes per year, have potentially dire consequences for the vehicle occupants and for the community if the firetruck was traveling to provide emergency services. Data from the United States Fire Administration and the National Highway Traffic Safety Administration shows that firefighters neglect to buckle their seatbelts while traveling in a fire apparatus, thus putting themselves at a high risk for injuries if the truck crashes, especially in rollover crashes. Despite national regulations and departmental guidelines aiming to improve safety on fire apparatuses, belt use among firefighters remains dangerously low. The results from this study indicate that further steps need to be taken to improve belt use. One promising solution would be to redesign firetruck seatbelts to improve the ease of buckling and to accommodate wider variations in firefighter sizes.

  5. How Does the Driver’s Perception Reaction Time Affect the Performances of Crash Surrogate Measures?

    PubMed Central

    Kuang, Yan; Qu, Xiaobo; Weng, Jinxian; Etemad-Shahidi, Amir

    2015-01-01

    With the merit on representing traffic conflict through examining the crash mechanism and causality proactively, crash surrogate measures have long been proposed and applied to evaluate the traffic safety. However, the driver’s Perception-Reaction Time (PRT), an important variable in crash mechanism, has not been considered widely into surrogate measures. In this regard, it is important to know how the PRT affects the performances of surrogate indicators. To this end, three widely used surrogate measures are firstly modified by involving the PRT into their crash mechanisms. Then, in order to examine the difference caused by the PRT, a comparative study is carried out on a freeway section of the Pacific Motorway, Australia. This result suggests that the surrogate indicators’ performances in representing rear-end crash risks are improved with the incorporating of the PRT for the investigated section. PMID:26398416

  6. The Association between Regional Environmental Factors and Road Trauma Rates: A Geospatial Analysis of 10 Years of Road Traffic Crashes in British Columbia, Canada

    PubMed Central

    Brubacher, Jeffrey R.; Chan, Herbert; Erdelyi, Shannon; Schuurman, Nadine; Amram, Ofer

    2016-01-01

    Background British Columbia, Canada is a geographically large jurisdiction with varied environmental and socio-cultural contexts. This cross-sectional study examined variation in motor vehicle crash rates across 100 police patrols to investigate the association of crashes with key explanatory factors. Methods Eleven crash outcomes (total crashes, injury crashes, fatal crashes, speed related fatal crashes, total fatalities, single-vehicle night-time crashes, rear-end collisions, and collisions involving heavy vehicles, pedestrians, cyclists, or motorcyclists) were identified from police collision reports and insurance claims and mapped to police patrols. Six potential explanatory factors (intensity of traffic law enforcement, speed limits, climate, remoteness, socio-economic factors, and alcohol consumption) were also mapped to police patrols. We then studied the association between crashes and explanatory factors using negative binomial models with crash count per patrol as the response variable and explanatory factors as covariates. Results Between 2003 and 2012 there were 1,434,239 insurance claim collisions, 386,326 police reported crashes, and 3,404 fatal crashes. Across police patrols, there was marked variation in per capita crash rate and in potential explanatory factors. Several factors were associated with crash rates. Percent roads with speed limits ≤ 60 km/hr was positively associated with total crashes, injury crashes, rear end collisions, and collisions involving pedestrians, cyclists, and heavy vehicles; and negatively associated with single vehicle night-time crashes, fatal crashes, fatal speeding crashes, and total fatalities. Higher winter temperature was associated with lower rates of overall collisions, single vehicle night-time collisions, collisions involving heavy vehicles, and total fatalities. Lower socio-economic status was associated with higher rates of injury collisions, pedestrian collisions, fatal speeding collisions, and fatal

  7. 78 FR 13756 - Technical Report: Effectiveness of LED Stop Lamps for Reducing Rear-End Crashes: Analyses of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-28

    ... (65 FR 19477) or you may visit http://www.regulations.gov . Please send two paper copies of your... Reducing Rear-End Crashes: Analyses of State Crash Data AGENCY: National Highway Traffic Safety.... The report's title is: Effectiveness of LED Stop Lamps for Reducing Rear-End Crashes: Analyses...

  8. Estimating the human recovery costs of seriously injured road crash casualties.

    PubMed

    Bambach, M R; Mitchell, R J

    2015-12-01

    Road crashes result in substantial trauma and costs to societies around the world. Robust costing methods are an important tool to estimate costs associated with road trauma, and are key inputs into policy development and cost-benefit analysis for road safety programmes and infrastructure projects. With an expanding focus on seriously injured road crash casualties, in addition to the long standing focus on fatalities, methods for costing seriously injured casualties are becoming increasingly important. Some road safety agencies are defining a seriously injured casualty as an individual that was admitted to hospital following a road crash, and as a result, hospital separation data provide substantial potential for estimating the costs associated with seriously injured road crash casualties. The aim of this study is to establish techniques for estimating the human recovery costs of (non-fatal) seriously injured road crash casualties directly from hospital separation data. An individuals' road crash-related hospitalisation record and their personal injury insurance claim were linked for road crashes that occurred in New South Wales, Australia. These records provided the means for estimating all of the costs to the casualty directly related to their recovery from their injuries. A total of 10,897 seriously injured road crash casualties were identified and four methods for estimating their recovery costs were examined, using either unit record or aggregated hospital separation data. The methods are shown to provide robust techniques for estimating the human recovery costs of seriously injured road crash casualties, that may prove useful for identifying, implementing and evaluating safety programmes intended to reduce the incidence of road crash-related serious injuries.

  9. Modeling the effect of operator and passenger characteristics on the fatality risk of motorcycle crashes

    PubMed Central

    Tavakoli Kashani, Ali; Rabieyan, Rahim; Besharati, Mohammad Mehdi

    2016-01-01

    Abstract: Background: In Iran more than 25% of crash fatalities belong to motorcycle operators and passengers in the recent years, from which about 20% are related to passenger fatalities. Methods: The aim of this study was to investigate the motorcycle operator and passenger characteristics as well as other contributory factors that may affect the fatality risk of motorcyclists involved in traffic crashes. To this end, motorcycle crash data between 2009 and 2012 was extracted from Iran traffic crash database and a logistic regression analysis was performed to obtain odds ratio estimates for each of the study variables. Results: The fatality risk of motorcyclists has a direct relationship with the number of pillion passengers carried. Results also indicate that the amount of increase in the likelihood of having a fatality in a motorcycles crash is considerably higher when the operator is accompanied by a male passenger of the same age. Furthermore, results showed that if the crash is occurred in the darkness, on curves, in rural areas and on highways, then the crash would be more likely to be fatal. Moreover, the head-on collisions, older operators, unlicensed operators and not using a safety helmet were found to increase the likelihood of a fatality in a motorcycle crash. Conclusions: Preventative measures such as, imposing stricter rules regarding safety helmet usage and confining the number of pillion passengers to one, might be implemented to reduce the fatality risk in motorcycle crashes. In addition, more appropriate infrastructures for penalizing offending motorcyclists could also reduce the frequency of law violations such as not wearing helmet or riding without motorcycle license, which in turn, would result into a reduction in the fatality risk of motorcycle crashes. PMID:26420217

  10. The prevalence and effective factors of crash helmet usage among motorcyclists in Iran

    PubMed Central

    Heydari, Seyed Taghi; Lankarani, Kamran B.; Vossoughi, Mehrdad; Javanmardi, Kazem; Sarikhani, Yaser; Mahjoor, Kourosh; Mahmoodi, Mojtaba; Khabaz Shirazi, Mohammad; Akbari, Maryam

    2016-01-01

    Abstract: Background: Crash helmet plays an important role in protecting the deriver's head during crashes and reduces the rate of severe injuries and fatalities. Although it has been proved that wearing the crash helmet can save the deriver’s life by around 42%; previous studies showed that the rate of wearing crash helmet has not been acceptable in Iran. Due to the huge number of motorcyclists on the roads in Iran, the use of crash helmet is an important area of research. The aim of this study was to assess the factors that could possibly relate to or affect the use of crash helmet by the motorcyclists. Methods: This is an observational study on 414 motorcyclists in Shiraz, Southern Iran. All participants completed a questioner containing demographic features, crash helmet use, motorcycle license, and the reasons for using motorcycles. Results: All the participants were males and aged from16 to 64 years with mean age 27±9.28. The results of logistic regression model revealed that only the drivers who had motorcycle license (OR=2.73, C.I: 1.40-7.24), employed the motorcycle for reasons other than pleasure (OR=3.18, C.I: 1.42-7.37) and been driving for 10 or more years (OR=1.92 95% C.I: 1.12-3.30) had greater rate of wearing crash helmet. Interestingly, educational levels, age, and other demographical variables had no relationship with crash helmet usage. Conclusions: It is believed that in order to increase the rate of crash helmet use, it is necessary to enact obligatory requirement for driving license by motorcyclists and increase the legal age for motorcycle driving. PMID:26353927

  11. Assessing the Residual Teen Crash Risk Factors after Graduated Drivers License Implementation

    PubMed Central

    Thor, Craig P.; Gabler, Hampton C.

    2010-01-01

    Graduated driving licensing laws are now in place in all 50 U.S. states and the District of Columbia. However, despite stricter supervised driving requirements, restrictions on the number of passengers, and earlier nighttime driving curfews, teen drivers continue to be at a higher crash risk than the adult driving population. The National Motor Vehicle Crash Causation Survey (NMVCCS) dataset was examined to compare and contrast the primary crash factors for teen drivers (16–18 years. old) and adult drivers (35–55 years. old) in the GDL era. It is was found that teen drivers were 2.40 (CI:1.19–4.85) times more likely to be in a control loss crash and 1.88 (CI:1.12–3.15) times more likely to be in a road departure crash relative adult drivers. Furthermore, teen drivers who were in a crash were 1.73 (CI:1.25–2.38) times more likely to be distracted, 1.83 (CI: 1.38–2.43) times more likely to be driving inappropriately, and 1.47 (CI:1.30–1.67) times more likely to be inadequately aware of their driving environment than adults. Passengers and aggressive driving also contributed significantly to the heightened crash risk for teen drivers, after GDL implementation. This study emphasizes that while the number of teen crashes has decreased with GDL, the relative crash risk for certain experience related causative factors and pre-crash scenarios remain high for teen drivers after GDL implementation nationwide. PMID:21050612

  12. Factors associated with pilot fatalities in work-related aircraft crashes--Alaska, 1990-1999.

    PubMed

    2002-04-26

    Despite its large geographic area, Alaska has only 12,200 miles of public roads, and 90% of the state's communities are not connected to a highway system. Commuter and air-taxi flights are essential for transportation of passengers and delivery of goods, services, and mail to outlying communities (Figure 1). Because of the substantial progress in decreasing fatalities in the fishing and logging industries, aviation crashes are the leading cause of occupational death in Alaska. During 1990-1999, aircraft crashes in Alaska caused 107 deaths among workers classified as civilian pilots. This is equivalent to 410 fatalities per 100,000 pilots each year, approximately five times the death rate for all U.S. pilots and approximately 100 times the death rate for all U.S. workers. As part of a collaborative aviation safety initiative that CDC's National Institute for Occupational Safety and Health (NIOSH) is implementing with the Federal Aviation Administration (FAA), the National Transportation Safety Board (NTSB), and the National Weather Service, CDC analyzed data from NTSB crash reports to determine factors associated with pilot fatalities in work-related aviation crashes in Alaska. This report summarizes the result of this analysis, which found that the following factors were associated with pilot fatalities: crashes involving a post-crash fire, flights in darkness or weather conditions requiring instrument use, crashes occurring away from an airport, and crashes in which the pilot was not using a shoulder restraint. Additional pilot training, improved fuel systems that are less likely to ignite in crashes, and company policies that discourage flying in poor weather conditions might help decrease pilot fatalities. More detailed analyses of crash data, collaborations with aircraft operators to improve safety, and evaluation of new technologies are needed. PMID:12004985

  13. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs.

  14. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs. PMID:26970365

  15. Cigarette tax avoidance and evasion.

    PubMed

    Stehr, Mark

    2005-03-01

    Variation in state cigarette taxes provides incentives for tax avoidance through smuggling, legal border crossing to low tax jurisdictions, or Internet purchasing. When taxes rise, tax paid sales of cigarettes will decline both because consumption will decrease and because tax avoidance will increase. The key innovation of this paper is to compare cigarette sales data to cigarette consumption data from the Behavioral Risk Factor Surveillance System (BRFSS). I show that after subtracting percent changes in consumption, residual percent changes in sales are associated with state cigarette tax changes implying the existence of tax avoidance. I estimate that the tax avoidance response to tax changes is at least twice the consumption response and that tax avoidance accounted for up to 9.6% of sales between 1985 and 2001. Because of the increase in tax avoidance, tax paid sales data understate the level of smoking and overstate the drop in smoking. I also find that the level of legal border crossing was very low relative to other forms of tax avoidance. If states have strong preferences for smoking control, they must pair high cigarette taxes with effective policies to curb smuggling and other forms of tax avoidance or employ alternative policies such as counter-advertising and smoking restrictions. PMID:15721046

  16. Severity of road crashes involving pedestrians in Metro Manila, Philippines.

    PubMed

    Verzosa, Nina; Miles, Rebecca

    2016-09-01

    Pedestrians are considered as one of the most vulnerable road users in less developed countries (LDCs). Yet, pedestrian safety remains poorly addressed in both urban and rural transportation plans in most LDCs. Since most pedestrian injury severity studies are conducted in developed countries, this study fills the gap with an inquiry focused on a highly urbanized region of an LDC that faces a rapid increase in car ownership and increasing pedestrian-related traffic injuries, documenting specific pedestrian safety issues and providing guidance for injury prevention measures in such places. Using the Metro Manila Accident Reporting and Analysis System (MMARAS) data from 2008 to 2011, this study combines binomial logistic regression and street level analysis that further explores the statistical results and examines other factors that contribute to collisions and increase the potential for serious injury or death in three cities in Metro Manila: Makati, Manila, and Quezon. The results of the binomial regression analysis show that traffic crashes that involve heavy and multiple vehicles, and an elderly pedestrian (60 years old and above), as well as those that occurred during the evening (7 pm to midnight) and late at night (1 am to 5 am) have significantly higher odds of resulting in a fatal outcome; when the crash involves a female pedestrian and when the road surface is wet the odds of a fatal outcome are lower. Moreover, by closely examining the environment of these roadways, the study finds that most pedestrian fatalities occur on high-speed, high-traffic-volume, multilane roadways, that are surrounded by land uses that generate a particularly problematic mix of heavy vehicular and pedestrian traffic. The street level analysis also finds that fatal pedestrian crashes occur close to different types of transit stations. The results of this study of three cities in Metro Manila, reflect the twofold challenge to pedestrian safety in rapidly urbanizing areas in

  17. Severity of road crashes involving pedestrians in Metro Manila, Philippines.

    PubMed

    Verzosa, Nina; Miles, Rebecca

    2016-09-01

    Pedestrians are considered as one of the most vulnerable road users in less developed countries (LDCs). Yet, pedestrian safety remains poorly addressed in both urban and rural transportation plans in most LDCs. Since most pedestrian injury severity studies are conducted in developed countries, this study fills the gap with an inquiry focused on a highly urbanized region of an LDC that faces a rapid increase in car ownership and increasing pedestrian-related traffic injuries, documenting specific pedestrian safety issues and providing guidance for injury prevention measures in such places. Using the Metro Manila Accident Reporting and Analysis System (MMARAS) data from 2008 to 2011, this study combines binomial logistic regression and street level analysis that further explores the statistical results and examines other factors that contribute to collisions and increase the potential for serious injury or death in three cities in Metro Manila: Makati, Manila, and Quezon. The results of the binomial regression analysis show that traffic crashes that involve heavy and multiple vehicles, and an elderly pedestrian (60 years old and above), as well as those that occurred during the evening (7 pm to midnight) and late at night (1 am to 5 am) have significantly higher odds of resulting in a fatal outcome; when the crash involves a female pedestrian and when the road surface is wet the odds of a fatal outcome are lower. Moreover, by closely examining the environment of these roadways, the study finds that most pedestrian fatalities occur on high-speed, high-traffic-volume, multilane roadways, that are surrounded by land uses that generate a particularly problematic mix of heavy vehicular and pedestrian traffic. The street level analysis also finds that fatal pedestrian crashes occur close to different types of transit stations. The results of this study of three cities in Metro Manila, reflect the twofold challenge to pedestrian safety in rapidly urbanizing areas in

  18. Wireless telephones and the risk of road crashes.

    PubMed

    Laberge-Nadeau, Claire; Maag, Urs; Bellavance, François; Lapierre, Sophie D; Desjardins, Denise; Messier, Stéphane; Saïdi, Abdelnasser

    2003-09-01

    In light of the rapidly increasing development of the cell phone market, the use of such equipment while driving raises the question of whether it is associated with an increased accident risk; and if so, what is its magnitude. This research is an epidemiological study on two large cohorts, namely users and non-users of cell phones, with the objective of verifying whether an association exists between cell phone use and road crashes, separating those with injuries. The Société de l'Assurance Automobile du Québec (SAAQ) mailed a questionnaire and letter of consent to 175000 licence holders for passenger vehicles. The questionnaire asked about exposure to risk, driving habits, opinions about activities likely to be detrimental to driving and accidents within the last 24 months. For cell phone users, questions pertaining to the use of the telephone were added. We received 36078 completed questionnaires, with a signed letter of consent. Four wireless phone companies provided the files on cell phone activity, and the SAAQ the files for 4 years of drivers' records and police reports. The three data sources were merged using an anonymized identification number. The statistical methods include logistic-normal regression models to estimate the strength of the links between the explanatory variables and crashes. The relative risk of all accidents and of accidents with injuries is higher for users of cell phones than for non-users. The relative risks (RR) for injury collisions and also for all collisions is 38% higher for men and women cell phone users. These risks diminish to 1.1 for men and 1.2 for women if other variables, such as the kilometres driven and driving habits are incorporated into the models. Similar results hold for several sub-groups. The most significant finding is a dose-response relationship between the frequency of cell phone use, and crash risks. The adjusted relative risks for heavy users are at least two compared to those making minimal use of cell

  19. AISI/DOE Technology Roadmap Program: Characterization of Fatigue and Crash Performance of New Generation High Strength Steels for Automotive Applications

    SciTech Connect

    Brenda Yan; Dennis Urban

    2003-04-21

    A 2-year project (2001-2002) to generate fatigue and high strain data for a new generation of high strength steels (HSS) has been completed in December 2002. The project tested eleven steel grades, including Dual Phase (DP) steels, Transformation-Induced Plasticity (TRIP) steels, Bake Hardenable (BH) steels, and conventional High Strength Low Alloy (HSLA) steels. All of these steels are of great interest in automotive industry due to the potential benefit in weight reduction, improved fuel economy, enhanced crash energy management and total system cost savings. Fatigue behavior includes strain controlled fatigue data notch sensitivity for high strength steels. High strain rate behavior includes stress-strain data for strain rates from 0.001/s to 1000/s, which are considered the important strain rate ranges for crash event. The steels were tested in two phases, seven were tested in Phase 1 and the remaining steels were tested in Phase. In a addition to the fatigue data and high st rain rate data generated for the steels studied in the project, analyses of the testing results revealed that Advanced High Strength Steels (AHSS) exhibit significantly higher fatigue strength and crash energy absorption capability than conventional HSS. TRIP steels exhibit exceptionally better fatigue strength than steels of similar tensile strength but different microstructure, for conditions both with or without notches present

  20. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance.

  1. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance. PMID:25387854

  2. Risk factors for severe injury in cyclists involved in traffic crashes in Victoria, Australia.

    PubMed

    Boufous, Soufiane; de Rome, Liz; Senserrick, Teresa; Ivers, Rebecca

    2012-11-01

    This study examines the impact of cyclist, road and crash characteristics on the injury severity of cyclists involved in traffic crashes reported to the police in Victoria, Australia between 2004 and 2008. Logistic regression analysis was carried out to identify predictors of severe injury (serious injury and fatality) in cyclist crashes reported to the police. There were 6432 cyclist crashes reported to the police in Victoria between 2004 and 2008 with 2181 (33.9%) resulting in severe injury of the cyclist involved. The multivariate analysis found that factors that increase the risk of severe injury in cyclists involved in traffic crashes were age (50 years and older), not wearing a helmet, riding in the dark on unlit roads, riding on roads zoned 70 km/h or above, on curved sections of the road, in rural locations and being involved in head-on collisions as well as off path crashes, which include losing control of vehicle, and on path crashes which include striking the door of a parked vehicle. While this study did not test effectiveness of preventative measures, policy makers should consider implementation of programs that address these risk factors including helmet programs and environmental modifications such as speed reduction on roads that are frequented by cyclists. PMID:23036419

  3. Road factors and bicycle-motor vehicle crashes at unsignalized priority intersections.

    PubMed

    Schepers, J P; Kroeze, P A; Sweers, W; Wüst, J C

    2011-05-01

    In this study, the safety of cyclists at unsignalized priority intersections within built-up areas is investigated. The study focuses on the link between the characteristics of priority intersection design and bicycle-motor vehicle (BMV) crashes. Across 540 intersections that are involved in the study, the police recorded 339 failure-to-yield crashes with cyclists in four years. These BMV crashes are classified into two types based on the movements of the involved motorists and cyclists: • type I: through bicycle related collisions where the cyclist has right of way (i.e. bicycle on the priority road); • type II: through motor vehicle related collisions where the motorist has right of way (i.e. motorist on the priority road). The probability of each crash type was related to its relative flows and to independent variables using negative binomial regression. The results show that more type I crashes occur at intersections with two-way bicycle tracks, well marked, and reddish coloured bicycle crossings. Type I crashes are negatively related to the presence of raised bicycle crossings (e.g. on a speed hump) and other speed reducing measures. The accident probability is also decreased at intersections where the cycle track approaches are deflected between 2 and 5m away from the main carriageway. No significant relationships are found between type II crashes and road factors such as the presence of a raised median.

  4. The shift to and from daylight savings time and motor vehicle crashes.

    PubMed

    Lambe, M; Cummings, P

    2000-07-01

    The objective of the study was to examine whether the shifts to and from daylight savings time in Sweden have short-term effects on the incidence of traffic crashes. A database maintained by the Swedish National Road Administration was used to examine crashes from 1984 through 1995, that occurred on state roads the Monday preceding, the Monday immediately after (index Monday), and the Monday 1 week after the change to daylight savings time in the spring and for the corresponding three Mondays in the autumn. The Mondays 1 week before and after the time changes were taken as representing the expected incidence of crashes. Crash incidence was calculated per 1000 person-years using population estimates for each year of the study. The association between 1 h of possible sleep loss and crash incidence was estimated by the incidence rate ratio from negative binomial regression. The incidence rate ratio was 1.04 (95% CI, 0.92-1.16) for a Monday on which drivers were expected to have had 1 h less sleep, compared with other Mondays. In the spring, the incidence rate ratio for crashes was 1.11 (95% CI, 0.93-1.31) for Mondays after the time change compared to other spring Mondays. The corresponding rate ratio for the fall was 0.98 (95% CI, 0.84-1.15) It was concluded that the shift to and from daylight savings time did not have measurable important immediate effects on crash incidence in Sweden.

  5. Estimate of air carrier and air taxi crash frequencies from high altitude en route flight operations

    SciTech Connect

    Sanzo, D.; Kimura, C.Y.; Prassinos, P.G.

    1996-06-03

    In estimating the frequency of an aircraft crashing into a facility, it has been found convenient to break the problem down into two broad categories. One category estimates the aircraft crash frequency due to air traffic from nearby airports, the so-called near-airport environment. The other category estimates the aircraft crash frequency onto facilities due to air traffic from airways, jet routes, and other traffic flying outside the near-airport environment The total aircraft crash frequency is the summation of the crash frequencies from each airport near the facility under evaluation and from all airways, jet routes, and other traffic near the facility of interest. This paper will examine the problems associated with the determining the aircraft crash frequencies onto facilities outside the near-airport environment. This paper will further concentrate on the estimating the risk of aircraft crashes to ground facilities due to high altitude air carrier and air taxi traffic. High altitude air carrier and air taxi traffic will be defined as all air carrier and air taxi flights above 18,000 feet Mean Sea Level (MSL).

  6. Prioritizing Highway Safety Manual's crash prediction variables using boosted regression trees.

    PubMed

    Saha, Dibakar; Alluri, Priyanka; Gan, Albert

    2015-06-01

    The Highway Safety Manual (HSM) recommends using the empirical Bayes (EB) method with locally derived calibration factors to predict an agency's safety performance. However, the data needs for deriving these local calibration factors are significant, requiring very detailed roadway characteristics information. Many of the data variables identified in the HSM are currently unavailable in the states' databases. Moreover, the process of collecting and maintaining all the HSM data variables is cost-prohibitive. Prioritization of the variables based on their impact on crash predictions would, therefore, help to identify influential variables for which data could be collected and maintained for continued updates. This study aims to determine the impact of each independent variable identified in the HSM on crash predictions. A relatively recent data mining approach called boosted regression trees (BRT) is used to investigate the association between the variables and crash predictions. The BRT method can effectively handle different types of predictor variables, identify very complex and non-linear association among variables, and compute variable importance. Five years of crash data from 2008 to 2012 on two urban and suburban facility types, two-lane undivided arterials and four-lane divided arterials, were analyzed for estimating the influence of variables on crash predictions. Variables were found to exhibit non-linear and sometimes complex relationship to predicted crash counts. In addition, only a few variables were found to explain most of the variation in the crash data.

  7. Novice Drivers' Risky Driving Behavior, Risk Perception, and Crash Risk: Findings From the DRIVE Study

    PubMed Central

    Senserrick, Teresa; Boufous, Soufiane; Stevenson, Mark; Chen, Huei-Yang; Woodward, Mark; Norton, Robyn

    2009-01-01

    Objectives. We explored the risky driving behaviors and risk perceptions of a cohort of young novice drivers and sought to determine their associations with crash risk. Methods. Provisional drivers aged 17 to 24 (n = 20 822) completed a detailed questionnaire that included measures of risk perception and behaviors; 2 years following recruitment, survey data were linked to licensing and police-reported crash data. Poisson regression models that adjusted for multiple confounders were created to explore crash risk. Results. High scores on questionnaire items for risky driving were associated with a 50% increased crash risk (adjusted relative risk = 1.51; 95% confidence interval = 1.25, 1.81). High scores for risk perception (poorer perceptions of safety) were also associated with increased crash risk in univariate and multivariate models; however, significance was not sustained after adjustment for risky driving. Conclusions. The overrepresentation of youths in crashes involving casualties is a significant public health issue. Risky driving behavior is strongly linked to crash risk among young drivers and overrides the importance of risk perceptions. Systemwide intervention, including licensing reform, is warranted. PMID:19608953

  8. Rainfall effect on single-vehicle crash severities using polychotomous response models.

    PubMed

    Jung, Soyoung; Qin, Xiao; Noyce, David A

    2010-01-01

    As part of the Wisconsin road weather safety initiative, the objective of this study is to assess the effects of rainfall on the severity of single-vehicle crashes on Wisconsin interstate highways utilizing polychotomous response models. Weather-related factors considered in this study include estimated rainfall intensity for 15 min prior to a crash occurrence, water film depth, temperature, wind speed/direction, stopping sight distance and deficiency of car-following distance at the crash moment. For locations with unknown weather information, data were interpolated using the inverse squared distance method. Non-weather factors such as road geometrics, traffic conditions, collision types, vehicle types, and driver and temporal attributes were also considered. Two types of polychotomous response models were compared: ordinal logistic and sequential logistic regressions. The sequential logistic regression was tested with forward and backward formats. Comparative models were also developed for single vehicle crash severity during clear weather. In conclusion, the backward sequential logistic regression model produced the best results for predicting crash severities in rainy weather where rainfall intensity, wind speed, roadway terrain, driver's gender, and safety belt were found to be statistically significant. Our study also found that the seasonal factor was significant in clear weather. The seasonal factor is a predictor suggesting that inclement weather may affect crash severity. These findings can be used to determine the probabilities of single vehicle crash severity in rainy weather and provide quantitative support on improving road weather safety via weather warning systems, highway facility improvements, and speed limit management.

  9. The stability of portfolio investment in stock crashes

    NASA Astrophysics Data System (ADS)

    Li, Yun-Xian; Qian, Zhen-Wei; Li, Jiang-Cheng; Tang, Nian-Sheng; Mei, Dong-Cheng

    2016-08-01

    The stability of portfolio investment in stock market crashes with Markowitz portfolio is investigated by the method of theoretical and empirical simulation. From numerical simulation of the mean escape time (MET), we conclude that: (i) The increasing number (Np) of stocks in Markowitz portfolio induces a maximum in the curve of MET versus the initial position; (ii) A critical value of Np in the behavior of MET versus the long-run variance or amplitude of volatility fluctuations maximumlly enhances the stability of portfolio investment. When Np takes value below the critical value, the increasing Np enhances the stability of portfolio investment, but restrains it when Np takes value above the critical value. In addition, a good agreement of both the MET and probability density functions of returns is found between real data and theoretical results.

  10. A multitask scientific investigation resolved an unusual road crash case.

    PubMed

    Rella, R; Sturaro, A; Casellato, U; Zernar, E

    2003-01-01

    Crime or accident scenes are sometimes almost unbelievable. Elements of the scene can be so strange that a reconstruction of the event is almost impossible. What can the investigator do in such a case? The only solution is to collect all the evidence and samples, even if they appear useless, and send them to specialised laboratories. Scientific data are held in high esteem by the law and court proceedings consequent on crashes will almost certainly require analytical results of one sort or another to be presented as evidence. The case presented is one of those strange and almost unbelievable cases with little physical evidence, no eyewitnesses and the almost fortuitous collection of one unique, incredibly small, sample. The prosecutor's decision to instruct unusual but appropriate experts turned out to be successful. PMID:12879570

  11. What the 2008 stock market crash means for retirement security.

    PubMed

    Butrica, Barbara A; Smith, Karen E; Toder, Eric J

    2010-10-01

    The 2008 stock market crash raises concerns about retirement security, especially since the increased prevalence of 401(k) and similar retirement saving plans means that more Americans are now stakeholders in the equity market than in the past. Using a dynamic microsimulation model, this paper explores the ability of alternate future stock market scenarios to restore retirement assets. The authors find that those near retirement could fare the worst because they have no time to recoup their losses. Mid-career workers could fare better because they have more time to rebuild their wealth. They may even gain income if they buy stocks at low prices and get above-average rates of return. High-income groups will be the most affected because they are most likely to have financial assets and to be invested in the stock market.

  12. Roadside tree/pole crash barrier field test

    NASA Technical Reports Server (NTRS)

    Wilson, A. H.

    1979-01-01

    A series of tests was carried out to evaluate the performance of a crash barrier designed to protect the occupants of an automobile from serious injury. The JPL barrier design is a configuration of empty aluminum beverage cans contained in a tear-resistant bag which, in turn, is encased in a collapsible container made of plywood and steel. Tests were conducted with a driven vehicle impacting the barrier. The basic requirements of NCHRP Report 153 were followed except that speeds of 30 mph rather than 60 mph were used. Accelerometer readings on the driver's helmet showed that the driver was never subjected to dangerous decelerations, and never experienced more than temporary discomfort. Also, all of the requirements of the cited report were met. An extrapolation of data indicated that the JPL barrier installed in front of a tree or telephone pole along a roadside would also have met the requirements at a speed of 40 mph.

  13. Objective test and performance measurement of automotive crash warning systems

    NASA Astrophysics Data System (ADS)

    Szabo, S.; Norcross, R. J.; Falco, J. A.

    2007-04-01

    The National Institute of Standards and Technology (NIST), under an interagency agreement with the United States Department of Transportation (DOT), is supporting development of objective test and measurement procedures for vehicle-based warning systems intended to warn an inattentive driver of imminent rear-end, road-departure and lane-change crash scenarios. The work includes development of track and on-road test procedures, and development of an independent measurement system, which together provide data for evaluating warning system performance. This paper will provide an overview of DOT's Integrated Vehicle-Based Safety System (IVBSS) program along with a review of the approach for objectively testing and measuring warning system performance.

  14. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  15. Obstructive Sleep Apnea and Risk of Motor Vehicle Crash: Systematic Review and Meta-Analysis

    PubMed Central

    Tregear, Stephen; Reston, James; Schoelles, Karen; Phillips, Barbara

    2009-01-01

    Study Objectives: We performed a systematic review of the OSA-related risk of crash in commercial motor vehicle (CMV) drivers. The primary objective involved determining whether individuals with obstructive sleep apnea (OSA) are at an increased risk for a motor vehicle crash when compared to comparable individuals who do not have the disorder. A secondary objective involved determining what factors are associated with an increased motor vehicle crash risk among individuals with OSA. Design/Setting: Seven electronic databases (MEDLINE, PubMed (PreMEDLINE), EMBASE, PsycINFO, CINAHL, TRIS, and the Cochrane library) were searched (through May 27, 2009), as well as the reference lists of all obtained articles. We included controlled studies (case-control or cohort) that evaluated crash risk in individuals with OSA. We evaluated the quality of each study and the interplay between the quality, quantity, robustness, and consistency of the body of evidence, and tested for publication bias. Data were extracted by 2 independent analysts. When appropriate, data from different studies were combined in a fixed- or random-effects meta-analysis. Results: Individuals with OSA are clearly at increased risk for crash. The mean crash-rate ratio associated with OSA is likely to fall within the range of 1.21 to 4.89. Characteristics that may predict crash in drivers with OSA include BMI, apnea plus hypopnea index, oxygen saturation, and possibly daytime sleepiness. Conclusions: Untreated sleep apnea is a significant contributor to motor vehicle crashes. Citation: Tregear S; Reston J; Schoelles K; Phillips B. Obstructive sleep apnea and risk of motor vehicle crash: systematic review and meta-analysis. J Clin Sleep Med 2009;5(6):573-581. PMID:20465027

  16. Off-Road Vehicle Crash Risk during the Six Months after a Birthday

    PubMed Central

    Woodfine, Jason D.; Thiruchelvam, Deva; Redelmeier, Donald A.

    2016-01-01

    Background Off-road vehicles are popular and thrilling for youth outside urban settings, yet sometimes result in a serious crash that requires emergency medical care. The relation between birthdays and the subsequent risk of an off-road vehicle crash is unknown. Methods We conducted a population-based before-and-after longitudinal analysis of youth who received emergency medical care in Ontario, Canada, due to an off-road vehicle crash between April 1, 2002, and March 31, 2014. We identified youth injured in an off-road vehicle crash through population-based health-care databases of individuals treated for medical emergencies. We included youth aged 19 years or younger, distinguishing juniors (age ≤ 15 years) from juveniles (age ≥ 16 years). Results A total 32,777 youths accounted for 35,202 emergencies due to off-road vehicle crashes within six months of their nearest birthday. Comparing the six months following a birthday to the six months prior to a birthday, crashes increased by about 2.7 events per 1000 juniors (18.3 vs 21.0, p < 0.0001). The difference equaled a 15% increase in relative risk (95% confidence interval 12 to 18). The increase extended for months following a birthday, was not observed for traffic crashes due to on-road vehicles, and was partially explained by a lack of helmet wearing. As expected, off-road crash risks did not change significantly following a birthday among juveniles (19.2 vs 19.8, p = 0.61). Conclusions Off-road vehicle crashes leading to emergency medical care increase following a birthday in youth below age 16 years. An awareness of this association might inform public health messages, gift-giving practices, age-related parental permissions, and prevention by primary care physicians. PMID:27695070

  17. Calibration of Airframe and Occupant Models for Two Full-Scale Rotorcraft Crash Tests

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Horta, Lucas G.; Polanco, Michael A.

    2012-01-01

    Two full-scale crash tests of an MD-500 helicopter were conducted in 2009 and 2010 at NASA Langley's Landing and Impact Research Facility in support of NASA s Subsonic Rotary Wing Crashworthiness Project. The first crash test was conducted to evaluate the performance of an externally mounted composite deployable energy absorber under combined impact conditions. In the second crash test, the energy absorber was removed to establish baseline loads that are regarded as severe but survivable. Accelerations and kinematic data collected from the crash tests were compared to a system integrated finite element model of the test article. Results from 19 accelerometers placed throughout the airframe were compared to finite element model responses. The model developed for the purposes of predicting acceleration responses from the first crash test was inadequate when evaluating more severe conditions seen in the second crash test. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used to calibrate model results for the second full-scale crash test. This combination of heuristic and quantitative methods was used to identify modeling deficiencies, evaluate parameter importance, and propose required model changes. It is shown that the multi-dimensional calibration techniques presented here are particularly effective in identifying model adequacy. Acceleration results for the calibrated model were compared to test results and the original model results. There was a noticeable improvement in the pilot and co-pilot region, a slight improvement in the occupant model response, and an over-stiffening effect in the passenger region. This approach should be adopted early on, in combination with the building-block approaches that are customarily used, for model development and test planning guidance. Complete crash simulations with validated finite element models can be used

  18. Hotspots and social background of urban traffic crashes: A case study in Cluj-Napoca (Romania).

    PubMed

    Benedek, József; Ciobanu, Silviu Marian; Man, Titus Cristian

    2016-02-01

    Mobility practices have changed dramatically in Romanian towns over the last 25 years, following the collapse of socialist mobility restrictions. Urban areas like Cluj-Napoca are facing both increasing immigration and car mobility, and therefore increasing levels of road traffic crashes. The analysis of traffic crashes is one of the most important elements for improving the road safety policy. This paper is divided in two parts. In the first one, the authors focus on identifying the traffic crash hotspots along the street network, while in the second part they discuss the social background of road traffic crash occurrence. The first step in analyzing traffic crashes is to determine crash hotspots. A four-year record (2010-2013) provided by the Traffic Department of the General Inspectorate of Romanian Police (GIRPTD) was used. As a method of hotspot determination, the Kernel Density Estimation tool was employed, in the frame of the spatial analysis along network (SANET). The outcome was the hotspot map of traffic crashes in Cluj-Napoca. The results have revealed 4 categories of street segments: not-dangerous, low-dangerous, medium-dangerous and high-dangerous. Based on this classification, at least 4 dangerous areas were identified, located at the city entrances-exits (in the West, North-West and East) and the city center (the most dangerous zone). The second part of the paper focuses on social groups involved in car crashes. The following are considered: age, gender and blood alcohol concentration of the person (driver or pedestrian) found guilty for every individual crash. PMID:26680130

  19. Inverse propensity weighting to adjust for bias in fatal crash samples

    PubMed Central

    Clark, David E.; Hannan, Edward L.

    2012-01-01

    Background The Fatality Analysis Reporting System (FARS) has data from all areas of the United States, but is limited to fatal crashes. The National Automotive Sampling System – General Estimates System (NASS-GES) includes all types of serious traffic crashes, but is limited to a few sampling areas. Combining the strengths of these two samples might offset their limitations. Methods Logistic regression (allowing for sample design, and conditional upon selected person-, event-, and geographic-level factors) was used to determine the propensity (PFC) for each injured person in 2002–2008 NASS-GES data to be in a fatal crash sample. NASS-GES subjects injured in fatal crashes were then reweighted by a factor of WFC = (1/PFC) to create a “pseudopopulation”. The weights (WFC) derived from NASS-GES were also applied to injured subjects in 2007 FARS data to create another pseudopopulation. Characteristics and mortality predictions from these artificial pseudopopulations were compared to those obtained using the original NASS-GES sample. The sum of WFC for FARS cases was also used to estimate the number of crash injuries for rural and urban locations, and compared to independently reported data. Results Compared to regression results using the original NASS-GES sample, unadjusted models based on fatal crash samples gave inaccurate estimates of covariate effects on mortality for injured subjects. After reweighting using WFC, estimates based upon the pseudopopulations were similar to results obtained using the original NASS-GES sample. The sum of WFC for FARS cases gave reasonable estimates for the number of crash injuries in rural and urban locations, and provided an estimate of the rural effect on mortality after controlling for other factors. Conclusions Weights derived from analysis of NASS-GES data (the inverse propensity for selection into a fatal crash sample) allow appropriate adjustment for selection bias in fatal crash samples, including FARS. PMID:23084095

  20. Motor-vehicle crash-injury risk factors among American Indians.

    PubMed

    Grossman, D C; Sugarman, J R; Fox, C; Moran, J

    1997-05-01

    The rates of motor-vehicle crash mortality are highest among American Indians and Alaska Natives, compared to other ethnic groups. The aim of this study was to compare risk factors for motor-vehicle crashes and occupant injuries between rural and urban American-Indian (AI) drivers, and between rural AI and non-AI rural drivers. A statewide traffic-accident database was linked to the Indian Health Service patient-registration database to identify crashes that involved American-Indian drivers. Using a cross-sectional design, crashes occurring in a two-county region during 1989 and 1990 were studied. A total of 9329 motor-vehicle crashes involving 16,234 drivers and 6431 passengers were studied. Two percent of drivers were American Indian. Compared to American-Indian drivers in urban crashes, rural crashes involving American-Indian drivers were more likely to result in injury or death (38% vs 64% p < 0.001). The difference in risk for crashes between urban and rural non-AI drivers was not as high (42% vs 33%). Only 44 percent of rural American-Indian motor-vehicle occupants reported wearing seat belts, compared to 70 percent of urban American-Indian occupants (p < 0.05). Rates of driver alcohol impairment, as assessed by the police, were much higher among AI drivers and highest among rural AI drivers. We conclude that, compared to non-American-Indian drivers, AI drivers are less likely to be restrained and more likely to be alcohol-impaired at the time of the crash. These risks are higher among rural AI drivers than urban AI drivers. PMID:9183469

  1. Assessment of methodologies for analysis of the dungeness B accidental aircraft crash risk.

    SciTech Connect

    LaChance, Jeffrey L.; Hansen, Clifford W.

    2010-09-01

    The Health and Safety Executive (HSE) has requested Sandia National Laboratories (SNL) to review the aircraft crash methodology for nuclear facilities that are being used in the United Kingdom (UK). The scope of the work included a review of one method utilized in the UK for assessing the potential for accidental airplane crashes into nuclear facilities (Task 1) and a comparison of the UK methodology against similar International Atomic Energy Agency (IAEA), United States (US) Department of Energy (DOE), and the US Nuclear Regulatory Commission (NRC) methods (Task 2). Based on the conclusions from Tasks 1 and 2, an additional Task 3 would provide an assessment of a site-specific crash frequency for the Dungeness B facility using one of the other methodologies. This report documents the results of Task 2. The comparison of the different methods was performed for the three primary contributors to aircraft crash risk at the Dungeness B site: airfield related crashes, crashes below airways, and background crashes. The methods and data specified in each methodology were compared for each of these risk contributors, differences in the methodologies were identified, and the importance of these differences was qualitatively and quantitatively assessed. The bases for each of the methods and the data used were considered in this assessment process. A comparison of the treatment of the consequences of the aircraft crashes was not included in this assessment because the frequency of crashes into critical structures is currently low based on the existing Dungeness B assessment. Although the comparison found substantial differences between the UK and the three alternative methodologies (IAEA, NRC, and DOE) this assessment concludes that use of any of these alternative methodologies would not change the conclusions reached for the Dungeness B site. Performance of Task 3 is thus not recommended.

  2. Hot-Air Balloon Tours: Crash Epidemiology in the United States, 2000-2011

    PubMed Central

    Ballard, Sarah-Blythe; Beaty, Leland P.; Baker, Susan P.

    2016-01-01

    Introduction Hot-air balloon tours are FAR Part 91-governed balloon rides conducted for compensation or hire. Part 91, General Aviation, in general involves the least strict federal regulations and accounts for the majority of aviation crashes and fatalities. Methods National Transportation Safety Board reports of hot-air balloon tour crashes in the United States from 2000 through 2011 were read and analyzed. Results During the 12-yr period, 78 hot-air balloon tours crashed, involving 518 occupants. There were 91 serious injuries and 5 fatalities; 83% of crashes resulted in one or more serious or fatal outcomes. Of the serious injuries characterized, 56% were lower extremity fractures. Most crashes (81%) occurred during landing; 65% involved hard landings. Fixed object collisions contributed to 50% of serious injuries and all 5 fatalities. During landing sequences, gondola dragging, tipping, bouncing, and occupant ejection were associated with poor outcomes. Of the crashes resulting in serious or fatal outcomes, 20% of balloons were significantly damaged or destroyed. Discussion The incidence of morbidity and mortality is high among hot-air balloon tour crashes, and the proportion of balloon crashes attributed to paid rides appears to have increased over time. In addition to examining the role of restraint systems, personal protective equipment, and power line emergency procedures in ballooning, injury prevention efforts should target factors such hard landings, object strikes, gondola instability, and occupant ejections, which are associated with balloon injuries and deaths. Crash outcomes may also improve with vehicle engineering that enables balloons themselves to absorb impact forces. PMID:24279231

  3. An epidemiological survey on road traffic crashes in Iran: application of the two logistic regression models.

    PubMed

    Bakhtiyari, Mahmood; Mehmandar, Mohammad Reza; Mirbagheri, Babak; Hariri, Gholam Reza; Delpisheh, Ali; Soori, Hamid

    2014-01-01

    Risk factors of human-related traffic crashes are the most important and preventable challenges for community health due to their noteworthy burden in developing countries in particular. The present study aims to investigate the role of human risk factors of road traffic crashes in Iran. Through a cross-sectional study using the COM 114 data collection forms, the police records of almost 600,000 crashes occurred in 2010 are investigated. The binary logistic regression and proportional odds regression models are used. The odds ratio for each risk factor is calculated. These models are adjusted for known confounding factors including age, sex and driving time. The traffic crash reports of 537,688 men (90.8%) and 54,480 women (9.2%) are analysed. The mean age is 34.1 ± 14 years. Not maintaining eyes on the road (53.7%) and losing control of the vehicle (21.4%) are the main causes of drivers' deaths in traffic crashes within cities. Not maintaining eyes on the road is also the most frequent human risk factor for road traffic crashes out of cities. Sudden lane excursion (OR = 9.9, 95% CI: 8.2-11.9) and seat belt non-compliance (OR = 8.7, CI: 6.7-10.1), exceeding authorised speed (OR = 17.9, CI: 12.7-25.1) and exceeding safe speed (OR = 9.7, CI: 7.2-13.2) are the most significant human risk factors for traffic crashes in Iran. The high mortality rate of 39 people for every 100,000 population emphasises on the importance of traffic crashes in Iran. Considering the important role of human risk factors in traffic crashes, struggling efforts are required to control dangerous driving behaviours such as exceeding speed, illegal overtaking and not maintaining eyes on the road.

  4. Urban bus drivers' sleep problems and crash accidents.

    PubMed

    Razmpa, Ebrahim; Sadegh Niat, Khosro; Saedi, Babak

    2011-07-01

    Sleep problems and their direct consequence, sleepiness, results in critical effects on psychomotor skills, memory, decision making, concentration and learning; all of which may play roles in accidents and errors. Despite the importance of quality of sleep among drivers there are only few researches that deal with them. Therefore, we designed this research to better understand possible relationships. This cross-sectional study was performed between 2006 and 2007 among 175 bus drivers of a transportation company in Tehran, the capital of Iran. Participants filled out a questionnaire concerning their demographic and personal history, associated disease, the insomnia index, the Epworth sleepiness scale (ESS), and the apnea index. Then they elaborated their history of crashes. Data was analyzed with the SPSS software through χ(2), Oneway ANOVAs, and Pearson correlation tests. The mean age, and body mass index (BMI) were 43.47 ± 6.85 years and 26.35 ± 3.87 kg/m(2). The mean duration of sleep among these drivers was 6.37 ± 1.62 h per day. The mean accident rate was 2.31 ± 1.83 per year. There was a significant correlation between the insomnia index and BMI (P = 0.014), age (0.00), marital status (0.00), associated disease (0.005), and drug history (0.028). There was a significant relationship between marital status and the ESS, and also between age and accident rate in the past years. Sleep problems were a frequent finding among the studied group and had a significant relationship with their crash history. These results can be an alarming sign to choose bus drivers more carefully and pay more attention to treating their sleep disorders.

  5. Overview Of Structural Behavior and Occupant Responses from Crash Test of a Composite Airplane

    NASA Technical Reports Server (NTRS)

    Jones, Lisa E.; Carden, Huey D.

    1995-01-01

    As part of NASA's composite structures crash dynamics research, a general aviation aircraft with composite wing, fuselage and empennage (but with metal subfloor structure) was crash tested at the NASA Langley Research Center Impact Research Facility. The test was conducted to determine composite aircraft structural behavior for crash loading conditions and to provide a baseline for a similar aircraft test with a modified subfloor. Structural integrity and cabin volume were maintained. Lumbar loads for dummy occupants in energy absorbing seats wer substantially lower than those in standard aircraft seats; however, loads in the standard seats were much higher that those recorded under similar conditions for an all-metallic aircraft.

  6. Cellphone bans and fatal motor vehicle crash rates in the United States.

    PubMed

    Lim, Siew Hoon; Chi, Junwook

    2013-05-01

    A number of states in the United States have laws restricting drivers from using cellphones. Using state-level panel data, we examined the effect of cellphone laws on fatal crashes in the United States between 2000 and 2010. Our results show that there is insufficient power to detect a reduction in overall fatal crash rates scaled by vehicle miles and population estimates. Cellphone bans, however, have significantly reduced the fatal crash rates of drivers in certain age cohorts. The effect was most pronounced among drivers between 18 and 34 years of age. We did not find any significant effect among drivers in the 55 and older age cohorts.

  7. Crash response data system for the controlled impact demonstration (CID) of a full scale transport aircraft

    NASA Technical Reports Server (NTRS)

    Calloway, Raymond S.; Knight, Vernie H., Jr.

    1986-01-01

    NASA Langley's Crash Response Data System (CRDS) which is designed to acquire aircraft structural and anthropomorphic dummy responses during the full-scale transport CID test is described. Included in the discussion are the system design approach, details on key instrumentation subsystems and operations, overall instrumentation crash performance, and data recovery results. Two autonomous high-environment digital flight instrumentation systems, DAS 1 and DAS 2, were employed to obtain research data from various strain gage, accelerometer, and tensiometric sensors installed in the B-720 test aircraft. The CRDS successfully acquired 343 out of 352 measurements of dynamic crash data.

  8. Propensity scores-potential outcomes framework to incorporate severity probabilities in the highway safety manual crash prediction algorithm.

    PubMed

    Sasidharan, Lekshmi; Donnell, Eric T

    2014-10-01

    Accurate estimation of the expected number of crashes at different severity levels for entities with and without countermeasures plays a vital role in selecting countermeasures in the framework of the safety management process. The current practice is to use the American Association of State Highway and Transportation Officials' Highway Safety Manual crash prediction algorithms, which combine safety performance functions and crash modification factors, to estimate the effects of safety countermeasures on different highway and street facility types. Many of these crash prediction algorithms are based solely on crash frequency, or assume that severity outcomes are unchanged when planning for, or implementing, safety countermeasures. Failing to account for the uncertainty associated with crash severity outcomes, and assuming crash severity distributions remain unchanged in safety performance evaluations, limits the utility of the Highway Safety Manual crash prediction algorithms in assessing the effect of safety countermeasures on crash severity. This study demonstrates the application of a propensity scores-potential outcomes framework to estimate the probability distribution for the occurrence of different crash severity levels by accounting for the uncertainties associated with them. The probability of fatal and severe injury crash occurrence at lighted and unlighted intersections is estimated in this paper using data from Minnesota. The results show that the expected probability of occurrence of fatal and severe injury crashes at a lighted intersection was 1 in 35 crashes and the estimated risk ratio indicates that the respective probabilities at an unlighted intersection was 1.14 times higher compared to lighted intersections. The results from the potential outcomes-propensity scores framework are compared to results obtained from traditional binary logit models, without application of propensity scores matching. Traditional binary logit analysis suggests that

  9. Vision-based obstacle avoidance

    DOEpatents

    Galbraith, John

    2006-07-18

    A method for allowing a robot to avoid objects along a programmed path: first, a field of view for an electronic imager of the robot is established along a path where the electronic imager obtains the object location information within the field of view; second, a population coded control signal is then derived from the object location information and is transmitted to the robot; finally, the robot then responds to the control signal and avoids the detected object.

  10. Analysis of Casualty Risk per Police-Reported Crash for Model Year 2000 to 2004 Vehicles, using Crash Data from Five States

    SciTech Connect

    Wenzel, Tom

    2011-03-20

    In this report we compare two measures of driver risks: fatality risk per vehicle registration-year, and casualty (fatality plus serious injury) risk per police-reported crash. Our analysis is based on three sets of data from five states (Florida, Illinois, Maryland, Missouri, and Pennsylvania): data on all police-reported crashes involving model year 2000 to 2004 vehicles; 2005 county-level vehicle registration data by vehicle model year and make/model; and odometer readings from vehicle emission inspection and maintenance (I/M) programs conducted in urban areas of four of the five states (Florida does not have an I/M program). The two measures of risk could differ for three reasons: casualty risks are different from fatality risk; risks per vehicle registration-year are different from risks per crash; and risks estimated from national data are different from risks from the five states analyzed here. We also examined the effect of driver behavior, crash location, and general vehicle design on risk, as well as sources of potential bias in using the crash data from five states.

  11. Predator Avoidance in Extremophile Fish

    PubMed Central

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis. PMID:25371337

  12. Predator avoidance in extremophile fish.

    PubMed

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis.

  13. Traffic jam driving with NMV avoidance

    NASA Astrophysics Data System (ADS)

    Milanés, Vicente; Alonso, Luciano; Villagrá, Jorge; Godoy, Jorge; de Pedro, Teresa; Oria, Juan P.

    2012-08-01

    In recent years, the development of advanced driver assistance systems (ADAS) - mainly based on lidar and cameras - has considerably improved the safety of driving in urban environments. These systems provide warning signals for the driver in the case that any unexpected traffic circumstance is detected. The next step is to develop systems capable not only of warning the driver but also of taking over control of the car to avoid a potential collision. In the present communication, a system capable of autonomously avoiding collisions in traffic jam situations is presented. First, a perception system was developed for urban situations—in which not only vehicles have to be considered, but also pedestrians and other non-motor-vehicles (NMV). It comprises a differential global positioning system (DGPS) and wireless communication for vehicle detection, and an ultrasound sensor for NMV detection. Then, the vehicle's actuators - brake and throttle pedals - were modified to permit autonomous control. Finally, a fuzzy logic controller was implemented capable of analyzing the information provided by the perception system and of sending control commands to the vehicle's actuators so as to avoid accidents. The feasibility of the integrated system was tested by mounting it in a commercial vehicle, with the results being encouraging.

  14. The impact of pedestal turbulence and electron inertia on edge-localized-mode crashes

    SciTech Connect

    Xi, P. W.; Xu, X. Q.; Diamond, P. H.

    2014-05-15

    We demonstrate that the occurrence of Edge-Localized-Modes (ELM) crashes does not depend only on the linear peeling-ballooning threshold, but also relies on nonlinear processes. Wave-wave interaction constrains the growth time of a mode, thus inducing a shift in the criterion for triggering an ELM crash. An ELM crash requires the P-B growth rate to exceed a critical value γ>γ{sub c}, where γ{sub c} is set by 1/τ{sup ¯}{sub c}, and τ{sup ¯}{sub c} is the averaged mode phase coherence time. For 0<γ<γ{sub c}, P-B turbulence develops but drives enhanced turbulent transport. We also show that electron inertia dramatically changes the instability threshold when density is low. However, P-B turbulence alone cannot generate enough current transport to allow fast reconnection during an ELM crash.

  15. White Sands Space Harbor Area 1, Crash/Rescue Standby Support GPS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    White Sands Space Harbor Area 1, Crash/Rescue Standby Support GPS Buildings, East side of Runway 17/35, approximately 2,650 feet north of intersection with Runway 23/05, White Sands, Dona Ana County, NM

  16. A dynamic mathematical test of international property securities bubbles and crashes

    NASA Astrophysics Data System (ADS)

    Hui, Eddie C. M.; Zheng, Xian; Wang, Hui

    2010-04-01

    This study investigates property securities bubbles and crashes by using a dynamic mathematical methodology developed from the previous research (Watanabe et al. 2007a, b [31,32]). The improved model is used to detect the bubble and crash periods in five international countries/cities (namely, United States, United Kingdom, Japan, Hong Kong and Singapore) from Jan, 2000 to Oct, 2008. By this model definition, we are able to detect the beginning of each bubble period even before it bursts. Meanwhile, the empirical results show that most of property securities markets experienced bubble periods between 2003 and 2007, and crashes happened in Apr 2008 triggered by the Subprime Mortgage Crisis of US. In contrast, Japan suffered the shortest bubble period and no evidence has documented the existence of crash there.

  17. Validation of Human Body Model VIRTHUMAN and its Implementation in Crash Scenarios

    NASA Astrophysics Data System (ADS)

    Jaroslav Maňas, Ing.; Luděk Kovář, Ing.; Jan Petřík, Ing.; Hana Čechová, Ing.; Stanislav Špirk, Ing.

    Standard virtual prototyping approach of passive safety field is based on virtual models of dummies, but human body models become to be more and more important for specific crash scenarios. VIRTHUMAN is human body model based on MBS (Multi-Body Structure) approach. The model consists of movable rigid segments, which represent proper mass of each human part and enables to evaluate injury criteria describing safety risks during crash scenarios. There is evident advantage of the MBS approach in simple preparation of crash configuration—human body positioning, reasonable calculation times and mainly its applicability for robust designs development respecting variety of human population. The project VIRTHUMAN is directed on development of scaling technique enabling to generate human model based on the standard anthropometric inputs. The contribution describes status of the VIRTHUMAN model, procedures of its validation and results in standard crash scenarios.

  18. Improving the crashworthiness of general aviation aircraft by crash injury investigations.

    PubMed

    Kirkham, W R

    1982-04-01

    An aircraft accident investigation program correlates injuries to occupants with the severity of impacts and structural changes in the crash. Findings brought to the attention of aircraft manufacturers have led to specific aircraft being made more crash-worthy. The finding of a failure in a shoulder harness attachment led to the strengthening of the attachment brace. The way a shoulder harness was joined to a lapbelt was modified following a noted failure. The finding of fractures of lapbelt and shoulder harness cable tiedowns led to the use of stronger cables and modification of the installation. Other findings resulted in a shoulder strap guide being placed on an inertia reel and a side-mounted seat being modified. Described also are three seat-related features which, although meeting FAA standards, during the dynamics of a crash may lack desirable energy attenuation. These findings illustrate the value of aircraft crash injury correlations. PMID:7082247

  19. Identification of four differently injured victims of the Mangalore air crash disaster.

    PubMed

    Herald D'Souza, Deepak; Vaswani, Vina Ravi; Badiadka, Kishor Kumar

    2013-01-01

    On the 22nd of May 2010, a Boeing 737-800 aircraft crashed at the Mangalore International Airport killing all but 8 of the 166 people on board. One of the most important roles of the forensic investigation is to identify the victims of the crash. This task was made even more difficult because of the fact that most of the bodies were charred beyond recognition. Four bodies were transported to a mortuary to undergo a postmortem examination, whereas the rest of the victims were examined elsewhere. There is a wide range of methods to identify victims of mass disasters ranging from simple facial recognition to highly complex DNA comparisons. This paper highlights the experience and methods used to describe various types of injuries associated with a plane crash and the methods and techniques used to successfully identify the four victims of the crash. Implications for forensic nurses are discussed.

  20. Full-Scale Crash Tests and Analyses of Three High-Wing Single

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Littell, Justin D.; Stimson, Chad M.; Jackson, Karen E.; Mason, Brian H.

    2015-01-01

    The NASA Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project was initiated in 2014 to assess the crash performance standards for the next generation of ELT systems. Three Cessna 172 aircraft have been acquired to conduct crash testing at NASA Langley Research Center's Landing and Impact Research Facility. Testing is scheduled for the summer of 2015 and will simulate three crash conditions; a flare to stall while emergency landing, and two controlled flight into terrain scenarios. Instrumentation and video coverage, both onboard and external, will also provide valuable data of airframe response. Full-scale finite element analyses will be performed using two separate commercial explicit solvers. Calibration and validation of the models will be based on the airframe response under these varying crash conditions.

  1. An insight into the performance of road barriers - redistribution of barrier-relevant crashes.

    PubMed

    Zou, Yaotian; Tarko, Andrew P

    2016-11-01

    Unlike most of traffic safety treatments that prevent crashes, road barriers reduce the severity of crash outcomes by replacing crashes with a high risk of severe injury and fatality (such as median crossover head-on collisions or collisions with high-hazard objects) with less risky events (such as collisions with barriers). This "crash conversion" is actually more complex than one-to-one replacement and it has not been studied yet. The published work estimated the reduction of selected types of crashes (typically, median crossover collisions) or the overall effect of barriers on crash severity. The objective of this study was to study the probabilities of various types of crash events possible under various road and barrier scenarios. The estimated probabilities are conditional given that at least one vehicle left the travelled way and the resulted crash had been recorded. The results are meant to deliver a useful insight onto the conversion of crashes by barriers from more to less risky to help better understand the mechanism of crash severity reduction. Such knowledge should allow engineers more accurate estimation of barriers' benefits and help researchers evaluate barriers' performance to improve the barrier's design. Seven barrier-relevant crash events possible after a vehicle departs the road could be identified based on the existing crash data and their probabilities estimated given the presence and location of three types of barriers: median concrete barriers, median and roadside W-beam steel guardrails, and high-tension median cable barriers. A multinomial logit model with variable outcomes was estimated based on 2049 barrier-relevant crashes occurred between 2003 and 2012 on 1258 unidirectional travelled ways in Indiana. The developed model allows calculating the changes in the probabilities of the barrier-relevant crash events. The results of this study indicated that road departures lead to less frequent crossings of unprotected (no barriers) medians

  2. Potential crash reduction benefits of shoulder rumble strips in two-lane rural highways.

    PubMed

    Khan, Mubassira; Abdel-Rahim, Ahmed; Williams, Christopher J

    2015-02-01

    This paper reports the findings from a study aimed at examining the effectiveness of shoulder rumble strips in reducing run-off-the-road (ROR) crashes on two-lane rural highways using the empirical Bayes (EB) before-and-after analysis method. Specifically, the study analyzed the effects of traffic volume, roadway geometry and paved right shoulder width on the effectiveness of shoulder rumble strips. The results of this study demonstrate the safety benefits of shoulder rumble strips in reducing the ROR crashes on two-lane rural highways using the state of Idaho 2001-2009 crash data. This study revealed a 14% reduction in all ROR crashes after the installation of shoulder rumble strips on 178.63miles of two-lane rural highways in Idaho. The results indicate that shoulder rumble strips were most effective on roads with relatively moderate curvature and right paved shoulder width of 3 feet and more.

  3. The Behavior of Conventional Airplanes in Situations Thought to Lead to Most Crashes

    NASA Technical Reports Server (NTRS)

    Weick, Fred E

    1931-01-01

    Simple flight tests were made on ten conventional airplanes for the purpose of determining their action in the following two situations, which are generally thought to precede and lead to a large proportion of airplane crashes.

  4. An insight into the performance of road barriers - redistribution of barrier-relevant crashes.

    PubMed

    Zou, Yaotian; Tarko, Andrew P

    2016-11-01

    Unlike most of traffic safety treatments that prevent crashes, road barriers reduce the severity of crash outcomes by replacing crashes with a high risk of severe injury and fatality (such as median crossover head-on collisions or collisions with high-hazard objects) with less risky events (such as collisions with barriers). This "crash conversion" is actually more complex than one-to-one replacement and it has not been studied yet. The published work estimated the reduction of selected types of crashes (typically, median crossover collisions) or the overall effect of barriers on crash severity. The objective of this study was to study the probabilities of various types of crash events possible under various road and barrier scenarios. The estimated probabilities are conditional given that at least one vehicle left the travelled way and the resulted crash had been recorded. The results are meant to deliver a useful insight onto the conversion of crashes by barriers from more to less risky to help better understand the mechanism of crash severity reduction. Such knowledge should allow engineers more accurate estimation of barriers' benefits and help researchers evaluate barriers' performance to improve the barrier's design. Seven barrier-relevant crash events possible after a vehicle departs the road could be identified based on the existing crash data and their probabilities estimated given the presence and location of three types of barriers: median concrete barriers, median and roadside W-beam steel guardrails, and high-tension median cable barriers. A multinomial logit model with variable outcomes was estimated based on 2049 barrier-relevant crashes occurred between 2003 and 2012 on 1258 unidirectional travelled ways in Indiana. The developed model allows calculating the changes in the probabilities of the barrier-relevant crash events. The results of this study indicated that road departures lead to less frequent crossings of unprotected (no barriers) medians

  5. Teen driver crash risk and associations with smoking and drowsy driving.

    PubMed

    Hutchens, Lauren; Senserrick, Teresa M; Jamieson, Patrick E; Romer, Dan; Winston, Flaura K

    2008-05-01

    Motor vehicle crashes are the leading cause of death for young people in the United States. The goal of this study was to identify risk factor profiles of teen and young adult drivers involved in crashes. General demographic and behavioral as well as driving-related factors were considered. Analysis of a nationally representative telephone survey of U.S. young drivers ages 14 to 22 (N=900) conducted in 2005 was restricted to 506 licensed drivers (learners excluded). Statistically significant univariate associations between factors of interest and the primary outcome, crash involvement (ever) as a driver, were identified and included within a multivariate logistic regression model, controlling for potential demographic confounders. Aside from length of licensure, only driving alone while drowsy and being a current smoker were associated with having been in a crash. Gaining a better understanding of these behaviors could enhance the development of more customized interventions for new drivers. PMID:18460353

  6. Analytical modeling of transport aircraft crash scenarios to obtain floor pulses

    NASA Technical Reports Server (NTRS)

    Wittlin, G.; Lackey, D.

    1983-01-01

    The KRAS program was used to analyze transport aircraft candidate crash scenarios. Aircraft floor pulses and seat/occupant responses are presented. Results show that: (1) longitudinal only pulses can be represented by equivalent step inputs and/or static requirements; (2) the L1649 crash test floor longitudinal pulse for the aft direction (forward inertia) is less than 9g static or an equivalent 5g pulse; aft inertia accelerations are extremely small ((ch76) 3g) for representative crash scenarios; (3) a viable procedure to relate crash scenario floor pulses to standard laboratory dynamic and static test data using state of the art analysis and test procedures was demonstrated; and (4) floor pulse magnitudes are expected to be lower for wide body aircraft than for smaller narrow body aircraft.

  7. How Common are Noise Sources on the Crash Arc of Malaysian Flight 370

    SciTech Connect

    Fenimore, Edward E.; Kunkle, Thomas David; Stead, Richard J.

    2014-10-21

    Malaysian Flight 370 disappeared nearly without a trace. Besides some communication handshakes to the INMASAT satellite, the Comprehensive Test Ban Treaty monitoring system could have heard the aircraft crash into the southern Indian Ocean. One noise event from Cape Leeuwin has been suggested by Stead as the crash and occurs within the crash location suggested by Kunkle at el. We analyze the hydrophone data from Cape Leeuwin to understand how common such noise events are on the arc of possible locations where Malaysian Flight 370 might have crashed. Few other noise sources were found on the arc. The noise event found by Stead is the strongest. No noise events are seen within the Australian Transportation Safety Board (ATSB) new search location until the 10th strongest event, an event which is very close to the noise level.

  8. A Story of a Crashed Plane in US-Mexican border

    NASA Astrophysics Data System (ADS)

    Bermudez, Luis; Hobona, Gobe; Vretanos, Peter; Peterson, Perry

    2013-04-01

    A plane has crashed on the US-Mexican border. The search and rescue command center planner needs to find information about the crash site, a mountain, nearby mountains for the establishment of a communications tower, as well as ranches for setting up a local incident center. Events like this one occur all over the world and exchanging information seamlessly is key to save lives and prevent further disasters. This abstract describes an interoperability testbed that applied this scenario using technologies based on Open Geospatial Consortium (OGC) standards. The OGC, which has about 500 members, serves as a global forum for the collaboration of developers and users of spatial data products and services, and to advance the development of international standards for geospatial interoperability. The OGC Interoperability Program conducts international interoperability testbeds, such as the OGC Web Services Phase 9 (OWS-9), that encourages rapid development, testing, validation, demonstration and adoption of open, consensus based standards and best practices. The Cross-Community Interoperability (CCI) thread in OWS-9 advanced the Web Feature Service for Gazetteers (WFS-G) by providing a Single Point of Entry Global Gazetteer (SPEGG), where a user can submit a single query and access global geographic names data across multiple Federal names databases. Currently users must make two queries with differing input parameters against two separate databases to obtain authoritative cross border geographic names data. The gazetteers in this scenario included: GNIS and GNS. GNIS or Geographic Names Information System is managed by USGS. It was first developed in 1964 and contains information about domestic and Antarctic names. GNS or GeoNET Names Server provides the Geographic Names Data Base (GNDB) and it is managed by National Geospatial Intelligence Agency (NGA). GNS has been in service since 1994, and serves names for areas outside the United States and its dependent areas, as

  9. Automatic Collision Avoidance Technology (ACAT)

    NASA Technical Reports Server (NTRS)

    Swihart, Donald E.; Skoog, Mark A.

    2007-01-01

    This document represents two views of the Automatic Collision Avoidance Technology (ACAT). One viewgraph presentation reviews the development and system design of Automatic Collision Avoidance Technology (ACAT). Two types of ACAT exist: Automatic Ground Collision Avoidance (AGCAS) and Automatic Air Collision Avoidance (AACAS). The AGCAS Uses Digital Terrain Elevation Data (DTED) for mapping functions, and uses Navigation data to place aircraft on map. It then scans DTED in front of and around aircraft and uses future aircraft trajectory (5g) to provide automatic flyup maneuver when required. The AACAS uses data link to determine position and closing rate. It contains several canned maneuvers to avoid collision. Automatic maneuvers can occur at last instant and both aircraft maneuver when using data link. The system can use sensor in place of data link. The second viewgraph presentation reviews the development of a flight test and an evaluation of the test. A review of the operation and comparison of the AGCAS and a pilot's performance are given. The same review is given for the AACAS is given.

  10. Approach/avoidance in dreams.

    PubMed

    Malcolm-Smith, Susan; Koopowitz, Sheri; Pantelis, Eleni; Solms, Mark

    2012-03-01

    The influential threat simulation theory (TST) asserts that dreaming yields adaptive advantage by providing a virtual environment in which threat-avoidance may be safely rehearsed. We have previously found the incidence of biologically threatening dreams to be around 20%, with successful threat avoidance occurring in approximately one-fifth of such dreams. TST asserts that threat avoidance is over-represented relative to other possible dream contents. To begin assessing this issue, we contrasted the incidence of 'avoidance' dreams with that of their opposite: 'approach' dreams. Because TST states that the threat-avoidance function is only fully activated in ecologically valid (biologically threatening) contexts, we also performed this contrast for populations living in both high- and low-threat environments. We find that 'approach' dreams are significantly more prevalent across both contexts. We suggest these results are more consistent with the view that dreaming is generated by reward-seeking systems than by fear-conditioning systems, although reward-seeking is clearly not the only factor determining the content of dreams.

  11. Vision-based on-board collision avoidance system for aircraft navigation

    NASA Astrophysics Data System (ADS)

    Candamo, Joshua; Kasturi, Rangachar; Goldgof, Dmitry; Sarkar, Sudeep

    2006-05-01

    This paper presents an automated classification system for images based on their visual complexity. The image complexity is approximated using a clutter measure, and parameters for processing it are dynamically chosen. The classification method is part of a vision-based collision avoidance system for low altitude aerial vehicles, intended to be used during search and rescue operations in urban settings. The collision avoidance system focuses on detecting thin obstacles such as wires and power lines. Automatic parameter selection for edge detection shows a 5% and 12% performance improvement for medium and heavily cluttered images respectively. The automatic classification enabled the algorithm to identify near invisible power lines in a 60 frame video footage from a SUAV helicopter crashing during a search and rescue mission at hurricane Katrina, without any manual intervention.

  12. The relationship between trauma and personality in victims of the Boeing 737-2D6C crash in Coventry.

    PubMed

    Chung, M C; Easthope, Y; Chung, C; Clark-Carter, D

    1999-05-01

    The aims of this paper were to (a) ascertain the extent of psychological distress and (b) identify the association between personality variables and psychological distress among individuals who had been exposed to an aircraft disaster in Coventry, U.K. Hundreds of people escaped death but were exposed to the impact of the disaster when a Boeing 737-2D6C 7T-VEE crashed into a woodland area on the edge of a large housing estate in Coventry, U.K. in 1994. Eighty-two residents were randomly chosen for interviews in which they were assessed using the Impact of Event Scale, the General Health Questionnaire, and the Eysenck Personality Questionnaire-R Short Scale (EPQ-R). The results showed that the Coventry residents' scores reached similar levels of intrusion and avoidance compared with standardized samples and the Lockerbie samples. Fifty-two percent reached the GHQ case level score, which was again similar to the Lockerbie residents. The Coventry residents were significantly less extroverted and neurotic than standardized samples. Stepwise multiple regression showed that there were associations between intrusion and neuroticism and intrusion and extroversion, as well as between avoidance and neuroticism.

  13. Isotropy of Ion Heating During a Sawtooth Crash in a reversed-field pinch

    SciTech Connect

    Den Hartog, D.J.; Craig, D.

    2000-08-01

    In the Madison Symmetric Torus reversed-field pinch, ions are impulsively heated during a sawtooth crash; the ion temperature more than doubles. Heating appears to be nearly isotropic; impurity ion temperature measured perpendicular to the magnetic field(t) is approximately equal to impurity ion temperature parallel to the magnetic field (T) during a sawtooth crash. Ion heating occurs simultaneously throughout the entire plasma volume, with no non-maxwellian distortion of the ion velocity distribution function.

  14. Occupant injury in rollover crashes - Contribution of planar impacts with objects and other vehicles.

    PubMed

    Ivarsson, Johan; Poplin, Gerald; McMurry, Tim; Crandall, Jeff; Kerrigan, Jason

    2015-12-01

    Planar impacts with objects and other vehicles may increase the risk and severity of injury in rollover crashes. The current study compares the frequency of injury measures (MAIS 2+, 3+, and 4+; fatal; AIS 2+ head and cervical spine; and AIS 3+ head and thorax) as well as vehicle type distribution (passenger car, SUV, van, and light truck), crash kinematics, and occupant demographics between single vehicle single event rollovers (SV Pure) and multiple event rollovers to determine which types of multiple event rollovers can be pooled with SV Pure to study rollover induced occupant injury. Four different types of multiple event rollovers were defined: single and multi-vehicle crashes for which the rollover is the most severe event (SV Prim and MV Prim) and single and multi-vehicle crashes for which the rollover is not the most severe event (SV Non-Prim and MV Non-Prim). Information from real world crashes was obtained from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the period from 1995 through 2011. Belted, contained or partially ejected, adult occupants in vehicles that completed 1-16 lateral quarter turns were assigned to one of the five rollover categories. The results showed that the frequency of injury in non-primary rollovers (SV Non-Prim and MV Non-Prim) involving no more than one roof inversion is substantially greater than in SV Pure, but that this disparity diminishes for crashes involving multiple inversions. It can further be concluded that for a given number of roof inversions, the distribution of injuries and crash characteristics in SV Pure and SV Prim crashes are sufficiently similar for these categories to be considered collectively for purposes of understanding etiologies and developing strategies for prevention.

  15. Estimating under-reporting of road crash injuries to police using multiple linked data collections.

    PubMed

    Watson, Angela; Watson, Barry; Vallmuur, Kirsten

    2015-10-01

    The reliance on police data for the counting of road crash injuries can be problematic, as it is well known that not all road crash injuries are reported to police which under-estimates the overall burden of road crash injuries. The aim of this study was to use multiple linked data sources to estimate the extent of under-reporting of road crash injuries to police in the Australian state of Queensland. Data from the Queensland Road Crash Database (QRCD), the Queensland Hospital Admitted Patients Data Collection (QHAPDC), Emergency Department Information System (EDIS), and the Queensland Injury Surveillance Unit (QISU) for the year 2009 were linked. The completeness of road crash cases reported to police was examined via discordance rates between the police data (QRCD) and the hospital data collections. In addition, the potential bias of this discordance (under-reporting) was assessed based on gender, age, road user group, and regional location. Results showed that the level of under-reporting varied depending on the data set with which the police data was compared. When all hospital data collections are examined together the estimated population of road crash injuries was approximately 28,000, with around two-thirds not linking to any record in the police data. The results also showed that the under-reporting was more likely for motorcyclists, cyclists, males, young people, and injuries occurring in Remote and Inner Regional areas. These results have important implications for road safety research and policy in terms of: prioritising funding and resources; targeting road safety interventions into areas of higher risk; and estimating the burden of road crash injuries.

  16. Car crash and injury among young drivers: contribution of social, circumstantial and car attributes.

    PubMed

    Laflamme, L; Vaez, M

    2007-03-01

    The objective of the study was to assess the independent contribution of individual, car and circumstantial features in severe and fatal car crashes involving young drivers. A prospective longitudinal, register-based cohort study was conducted at national level (in Sweden), in which people born in the years 1970-1972 (n = 334070) were followed up for the period 1988-2000 (aged 16-18 years in 1988) for their first two-car crashes leading to severe or fatal injury. Ten variables descriptive of the driver (sociodemographics), the car (safety level) and the crash have been analysed using multiple logistic regressions for male and female drivers separately, compiling crude and adjusted odds ratios with 95% CI. When controlling for other features, none of the variables descriptive of male and female drivers' socio-demographic characteristics impacts significantly on the odds of being severely injured or dying in a car-to-car crash. After adjustment, significant excess risks are observed for speed limits higher than the lowest one, type of crash other than rear end collision and road and light conditions other than favourable (dry and daylight), for both male and female drivers. For males only, cars from all car safety levels have significantly higher odds than those from the safest category. Among male and female young drivers, class differences in the risk of being severely injured in a traffic injury are substantial. Yet, despite this imbalance, crash characteristics (for males and females) and safety level of the vehicle driven (for males) remain the most determinant factors of crash severity. Understanding the social patterning of road traffic injuries is a challenge for public health and it seems that qualitative and quantitative differences in crash exposure offer part of the explanation. Young drivers from all social groups need, however, to be sensitized to the risk factors.

  17. Occupant injury in rollover crashes - Contribution of planar impacts with objects and other vehicles.

    PubMed

    Ivarsson, Johan; Poplin, Gerald; McMurry, Tim; Crandall, Jeff; Kerrigan, Jason

    2015-12-01

    Planar impacts with objects and other vehicles may increase the risk and severity of injury in rollover crashes. The current study compares the frequency of injury measures (MAIS 2+, 3+, and 4+; fatal; AIS 2+ head and cervical spine; and AIS 3+ head and thorax) as well as vehicle type distribution (passenger car, SUV, van, and light truck), crash kinematics, and occupant demographics between single vehicle single event rollovers (SV Pure) and multiple event rollovers to determine which types of multiple event rollovers can be pooled with SV Pure to study rollover induced occupant injury. Four different types of multiple event rollovers were defined: single and multi-vehicle crashes for which the rollover is the most severe event (SV Prim and MV Prim) and single and multi-vehicle crashes for which the rollover is not the most severe event (SV Non-Prim and MV Non-Prim). Information from real world crashes was obtained from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the period from 1995 through 2011. Belted, contained or partially ejected, adult occupants in vehicles that completed 1-16 lateral quarter turns were assigned to one of the five rollover categories. The results showed that the frequency of injury in non-primary rollovers (SV Non-Prim and MV Non-Prim) involving no more than one roof inversion is substantially greater than in SV Pure, but that this disparity diminishes for crashes involving multiple inversions. It can further be concluded that for a given number of roof inversions, the distribution of injuries and crash characteristics in SV Pure and SV Prim crashes are sufficiently similar for these categories to be considered collectively for purposes of understanding etiologies and developing strategies for prevention. PMID:26418467

  18. Motor vehicle crashes during pregnancy and cerebral palsy during infancy: a longitudinal cohort analysis

    PubMed Central

    Redelmeier, Donald A; Naqib, Faisal; Thiruchelvam, Deva; R Barrett, Jon F

    2016-01-01

    Objectives To assess the incidence of cerebral palsy among children born to mothers who had their pregnancy complicated by a motor vehicle crash. Design Retrospective longitudinal cohort analysis of children born from 1 April 2002 to 31 March 2012 in Ontario, Canada. Participants Cases defined as pregnancies complicated by a motor vehicle crash and controls as remaining pregnancies with no crash. Main outcome Subsequent diagnosis of cerebral palsy by age 3 years. Results A total of 1 325 660 newborns were analysed, of whom 7933 were involved in a motor vehicle crash during pregnancy. A total of 2328 were subsequently diagnosed with cerebral palsy, equal to an absolute risk of 1.8 per 1000 newborns. For the entire cohort, motor vehicle crashes correlated with a 29% increased risk of subsequent cerebral palsy that was not statistically significant (95% CI −16 to +110, p=0.274). The increased risk was only significant for those with preterm birth who showed an 89% increased risk of subsequent cerebral palsy associated with a motor vehicle crash (95% CI +7 to +266, p=0.037). No significant increase was apparent for those with a term delivery (95% CI −62 to +79, p=0.510). A propensity score-matched analysis of preterm births (n=4384) yielded a 138% increased relative risk of cerebral palsy associated with a motor vehicle crash (95% CI +27 to +349, p=0.007), equal to an absolute increase of about 10.9 additional cases per 1000 newborns (18.2 vs 7.3, p=0.010). Conclusions Motor vehicle crashes during pregnancy may be associated with an increased risk of cerebral palsy among the subgroup of cases with preterm birth. The increase highlights a specific role for traffic safety advice in prenatal care. PMID:27650764

  19. Manitoba crash a wake-up call for "fly-in" physicians

    PubMed Central

    Square, D

    1998-01-01

    A December plane crash in northern Manitoba served to remind the province's "fly-in" physicians of the perils their work may entail. Four people were killed and 13 injured in the crash, which left Dr. Gerry Huot in serious condition in a Winnipeg hospital. The accident caused a serious head injury, and 4 months later he remains in hospital. It is causing some physicians to rethink their travel plans. PMID:9580740

  20. Motive to Avoid Success, Locus of Control, and Reinforcement Avoidance.

    ERIC Educational Resources Information Center

    Katovsky, Walter

    Subjects were four groups of 12 college women, high or low in motive to avoid success (MAS) and locus of control (LC), were reinforced for response A on a fixed partial reinforcement schedule on three concept learning tasks, one task consisting of combined reward and punishment, another of reward only, and one of punishment only. Response B was…

  1. Food Avoidance Diets for Dermatitis.

    PubMed

    Scott, Jeffrey F; Hammond, Margaret I; Nedorost, Susan T

    2015-10-01

    Food allergy is relatively common in both children and adults, and its prevalence is increasing. Early exposure of food allergens onto skin with an impaired epidermal barrier predisposes to sensitization and prevents the development of oral tolerance. While immediate-type food allergies are well described, less is known about delayed-type food allergies manifesting as dermatitis. This is due, in part, to limitations with current diagnostic testing for delayed-type food allergy, including atopy patch testing. We conducted a systematic review of food avoidance diets in delayed-type food allergies manifesting as dermatitis. While beneficial in some clinical circumstances, avoidance diets should be used with caution in infants and children, as growth impairment and developmental delay may result. Ultimately, dermatitis is highly multifactorial and avoidance diets may not improve symptoms of delayed-type food allergy until combined with other targeted therapies, including restoring balance in the skin microbiome and re-establishing proper skin barrier function.

  2. A problem of collision avoidance

    NASA Technical Reports Server (NTRS)

    Vincent, T. L.; Cliff, E. M.; Grantham, W. J.; Peng, W. Y.

    1972-01-01

    Collision avoidance between two vehicles of constant speed with limited turning radii, moving in a horizontal plane is investigated. Collision avoidance is viewed as a game by assuming that the operator of one vehicle has perfect knowledge of the state of the other, whereas the operator of the second vehicle is unaware of any impending danger. The situation envisioned is that of an encounter between a commercial aircraft and a small light aircraft. This worse case situation is examined to determine the conditions under which the commercial aircraft should execute a collision avoidance maneuver. Three different zones of vulnerability are defined and the boundaries, or barriers, between these zones are determined for a typical aircraft encounter. A discussion of the methods used to obtain the results as well as some of the salient features associated with the resultant barriers is included.

  3. How the choice of safety performance function affects the identification of important crash prediction variables.

    PubMed

    Wang, Ketong; Simandl, Jenna K; Porter, Michael D; Graettinger, Andrew J; Smith, Randy K

    2016-03-01

    Across the nation, researchers and transportation engineers are developing safety performance functions (SPFs) to predict crash rates and develop crash modification factors to improve traffic safety at roadway segments and intersections. Generalized linear models (GLMs), such as Poisson or negative binomial regression, are most commonly used to develop SPFs with annual average daily traffic as the primary roadway characteristic to predict crashes. However, while more complex to interpret, data mining models such as boosted regression trees have improved upon GLMs crash prediction performance due to their ability to handle more data characteristics, accommodate non-linearities, and include interaction effects between the characteristics. An intersection data inventory of 36 safety relevant parameters for three- and four-legged non-signalized intersections along state routes in Alabama was used to study the importance of intersection characteristics on crash rate and the interaction effects between key characteristics. Four different SPFs were investigated and compared: Poisson regression, negative binomial regression, regularized generalized linear model, and boosted regression trees. The models did not agree on which intersection characteristics were most related to the crash rate. The boosted regression tree model significantly outperformed the other models and identified several intersection characteristics as having strong interaction effects.

  4. Partial proportional odds model-an alternate choice for analyzing pedestrian crash injury severities.

    PubMed

    Sasidharan, Lekshmi; Menéndez, Mónica

    2014-11-01

    The conventional methods for crash injury severity analyses include either treating the severity data as ordered (e.g. ordered logit/probit models) or non-ordered (e.g. multinomial models). The ordered models require the data to meet proportional odds assumption, according to which the predictors can only have the same effect on different levels of the dependent variable, which is often not the case with crash injury severities. On the other hand, non-ordered analyses completely ignore the inherent hierarchical nature of crash injury severities. Therefore, treating the crash severity data as either ordered or non-ordered results in violating some of the key principles. To address these concerns, this paper explores the application of a partial proportional odds (PPO) model to bridge the gap between ordered and non-ordered severity modeling frameworks. The PPO model allows the covariates that meet the proportional odds assumption to affect different crash severity levels with the same magnitude; whereas the covariates that do not meet the proportional odds assumption can have different effects on different severity levels. This study is based on a five-year (2008-2012) national pedestrian safety dataset for Switzerland. A comparison between the application of PPO models, ordered logit models, and multinomial logit models for pedestrian injury severity evaluation is also included here. The study shows that PPO models outperform the other models considered based on different evaluation criteria. Hence, it is a viable method for analyzing pedestrian crash injury severities.

  5. A Combined Water-Bromotrifluoromethane Crash-Fire Protection System for a T-56 Turbopropeller Engine

    NASA Technical Reports Server (NTRS)

    Campbell, John A.; Busch, Arthur M.

    1959-01-01

    A crash-fire protection system is described which will suppress the ignition of crash-spilled fuel that may be ingested by a T-56 turbo-propeller engine. This system includes means for rapidly extinguishing the combustor flame, means for cooling and inerting with water the hot engine parts likely to ignite engine ingested fuel, and means for blanketing with bromotrifluoromethane massive metal parts that may reheat after the engine stops rotating. Combustion-chamber flames were rapidly extinguished at the engine fuel nozzles by a fuel shutoff and drain valve. Hot engine parts were inerted and cooled by 42 pounds of water discharged at seven engine stations. Massive metal parts that could reheat were inerted with 10 pounds of bromotrifluoromethane discharged at two engine stations. Performance trials of the crash-fire protection system were conducted by bringing the engine up to takeoff temperature, actuating the crash-fire protection system, and then spraying fuel into the engine to simulate crash-ingested fuel. No fires occurred during these trials, although fuel was sprayed into the engine from 0.3 second to 15 minutes after actuating the crash-fire protection system.

  6. Driving risk assessment using near-crash database through data mining of tree-based model.

    PubMed

    Wang, Jianqiang; Zheng, Yang; Li, Xiaofei; Yu, Chenfei; Kodaka, Kenji; Li, Keqiang

    2015-11-01

    This paper considers a comprehensive naturalistic driving experiment to collect driving data under potential threats on actual Chinese roads. Using acquired real-world naturalistic driving data, a near-crash database is built, which contains vehicle status, potential crash objects, driving environment and road types, weather condition, and driver information and actions. The aims of this study are summarized into two aspects: (1) to cluster different driving-risk levels involved in near-crashes, and (2) to unveil the factors that greatly influence the driving-risk level. A novel method to quantify the driving-risk level of a near-crash scenario is proposed by clustering the braking process characteristics, namely maximum deceleration, average deceleration, and percentage reduction in vehicle kinetic energy. A classification and regression tree (CART) is employed to unveil the relationship among driving risk, driver/vehicle characteristics, and road environment. The results indicate that the velocity when braking, triggering factors, potential object type, and potential crash type exerted the greatest influence on the driving-risk levels in near-crashes.

  7. Data development technical support document for the aircraft crash risk analysis methodology (ACRAM) standard

    SciTech Connect

    Kimura, C.Y.; Glaser, R.E.; Mensing, R.W.; Lin, T.; Haley, T.A.; Barto, A.B.; Stutzke, M.A.

    1996-08-01

    The Aircraft Crash Risk Analysis Methodology (ACRAM) Panel has been formed by the US Department of Energy Office of Defense Programs (DOE/DP) for the purpose of developing a standard methodology for determining the risk from aircraft crashes onto DOE ground facilities. In order to accomplish this goal, the ACRAM panel has been divided into four teams, the data development team, the model evaluation team, the structural analysis team, and the consequence team. Each team, consisting of at least one member of the ACRAM plus additional DOE and DOE contractor personnel, specializes in the development of the methodology assigned to that team. This report documents the work performed by the data development team and provides the technical basis for the data used by the ACRAM Standard for determining the aircraft crash frequency. This report should be used to provide the generic data needed to calculate the aircraft crash frequency into the facility under consideration as part of the process for determining the aircraft crash risk to ground facilities as given by the DOE Standard Aircraft Crash Risk Assessment Methodology (ACRAM). Some broad guidance is presented on how to obtain the needed site-specific and facility specific data but this data is not provided by this document.

  8. The odds of wrong-way crashes and resulting fatalities: A comprehensive analysis.

    PubMed

    Ponnaluri, Raj V

    2016-03-01

    The United States of America and other nations are grappling with the incidence of wrong-way driving (WWD). The issue is as important today (NTSB, 2012) as it was a half-century ago (Hulbert and Beers, 1966). In the absence of a comprehensive analysis, any effort to implement WWD countermeasures can be counterproductive. Hence, this effort began with the express intent to identify the factors that cause WWD crashes and fatalities. This work is sizeable in that it evaluated one million complete crash records from Florida. The methodology comprised (a) administering a survey on the perceptions about WWD; (b) developing binomial logistic models for computing the odds of WWD crashes, and of fatal crashes within the WWD space; (c) analyzing the contributing variables; and (d) comparing perceptions with crash analysis results. The study parameters included driver's age, gender, licensing state, physical defect, blood alcohol concentration, vehicle use, seatbelt compliance, day and time of crash, roadway lighting, facility type, weather conditions, road geometrics, and traffic volumes. Individual variable analysis of 23 parameters and the model development process included the determination of odds ratios and statistical tests for the predictive power and goodness-of-fit. The results of this work are generally consistent with expectation, yet surprising at times. This work concludes with decision-making inputs to the scientist, policy-maker and practitioner on the need for effectively engineering the roads, actively educating people about wrong-way driving, and strictly enforcing traffic laws, rules and regulations.

  9. Coverage of motor vehicle crashes with injuries in U.S. newspapers, 1999–2002

    PubMed Central

    Rosales, Monica

    2008-01-01

    Problem The aims of the study were to evaluate information on motor-vehicle crashes with injuries provided in newspaper reports and to assess the frequency of thematic and episodic reporting of motor-vehicle crashes. Method The present study used Fatal Analysis Reporting System (FARS) derived variables to code a nationally representative sample of U.S. newspaper reports of motor-vehicle crashes from 1999–2002. A total 473 newspaper reports of motor-vehicle crashes with injuries were included. Information on the crash event, people involved, and vehicles was extracted. The reports were coded for episodic and thematic news framing. Results A majority of newspaper reports used episodic framing. The majority of reports included information on the type of crash, but characteristics about people and vehicles were rarely reported. Discussion Lack of information in newspapers makes them an incomplete source from which to influence public perceptions and attitudes. Impact on industry This provides an opportunity for news print media to improve public health content. PMID:19010121

  10. Neck strain in car occupants: injury status after 6 months and crash-related factors.

    PubMed

    Ryan, G A; Taylor, G W; Moore, V M; Dolinis, J

    1994-10-01

    In this study, 29 individuals who sustained a neck strain as a result of a car crash were drawn from a group of physiotherapy and general practices and were followed up after 6 months. The aim was to examine relationships between the state of the neck injury at the time of follow up and crash-related factors, notably crash severity and occupant awareness. Crash severity was assessed by measurement of damage to the involved vehicles, while 6-month injury status was established through physical examinations and interviews. No statistically significant associations between crash severity and 6-month injury status were found, but subjects who were unaware of the impending collision had a greatly increased likelihood of experiencing persisting symptoms of and/or signs of neck strain, compared with those who were aware (odds ratio = 15.0; 95 per cent confidence limits: 1.8, 178). While the role of crash severity in the production and duration of neck strains remains unclear, awareness appears to have a strong protective influence and may prove to be a useful prognostic indicator in clinical settings.

  11. The role of conspicuity in preventing bicycle crashes involving a motor vehicle

    PubMed Central

    Woodward, Alistair; Ameratunga, Shanthi

    2015-01-01

    Background: Bicycle use, despite its proven health and other benefits, is rarely part of everyday travel for many people due to the perceived risk of injury from collision crashes. This article investigated the role of physical vs. attention conspicuity in preventing bicycle crashes involving a motor vehicle in New Zealand. Methods: The Taupo Bicycle Study involved 2590 adult cyclists recruited in 2006 (43.1% response rate) and followed for bicycle crash outcomes through linkage to four national databases. A composite measure of physical conspicuity was created using latent class analysis based on the use of fluorescent colours, lights and reflective materials, and the main colour of top, helmet and bike frame. Attention conspicuity was assessed based on regional differences in travel patterns and the amount of riding in a bunch. Cox regression modelling for repeated events was performed with multivariate adjustments. Results: During a median follow-up period of 6.4 years, 162 participants experienced 187 bicycle–motor vehicle crashes. The crash risk was not predicted by the four latent classes identified and the amount of bunch riding but was higher in Auckland, the region with the lowest level of bicycle use relative to car use. In subgroup analyses, compared to other latent classes, the most physically conspicuous group had a higher risk in Auckland but a lower risk in other regions. Conclusion: Conspicuity aids may not be effective in preventing bicycle–motor vehicle crashes in New Zealand, particularly in Auckland, where attention conspicuity is low. PMID:25085469

  12. Hit-and-run crashes in urban river-crossing road tunnels.

    PubMed

    Jiang, Chenming; Lu, Linjun; Chen, Shengdi; Lu, Jian John

    2016-10-01

    Hit-and-run crashes are a relatively infrequent but severe offense worldwide because the identification and emergency rescue of victims is delayed, which increases the injury severities and the mortality rate. However, no studies have been conducted on hit-and-run crashes in urban river-crossing road tunnels (URCRTs), which can greatly threaten the safety of motorists driving in the tunnels. This study, which employs a dataset of vehicle crashes that happened in thirteen urban road tunnels traversing the Huangpu River, established a binary logistic regression model to identify thirteen factors that contribute to escaping after crashes in Shanghai related to the offending drivers, the vehicular and environmental conditions, the tunnel characteristics and crash information. Among the thirty-five variables considered, this study found that a perpetrator's tendency to leave the crash scene without reporting an accident was higher at night, in the tunnel exit, near to or in short tunnels, when a two-wheeled vehicle or heavy goods vehicle (HGV) was involved and when alcohol was involved. While a perpetrator was more likely to remain on the scene in the tunnel entrance, on a rainy day, in a rear end collision, when a bus was involved, in a single vehicle or a multi-vehicle accident. Based on these findings, several countermeasures for better supervision and hit-and-run prevention are proposed.

  13. Exploring the application of latent class cluster analysis for investigating pedestrian crash injury severities in Switzerland.

    PubMed

    Sasidharan, Lekshmi; Wu, Kun-Feng; Menendez, Monica

    2015-12-01

    One of the major challenges in traffic safety analyses is the heterogeneous nature of safety data, due to the sundry factors involved in it. This heterogeneity often leads to difficulties in interpreting results and conclusions due to unrevealed relationships. Understanding the underlying relationship between injury severities and influential factors is critical for the selection of appropriate safety countermeasures. A method commonly employed to address systematic heterogeneity is to focus on any subgroup of data based on the research purpose. However, this need not ensure homogeneity in the data. In this paper, latent class cluster analysis is applied to identify homogenous subgroups for a specific crash type-pedestrian crashes. The manuscript employs data from police reported pedestrian (2009-2012) crashes in Switzerland. The analyses demonstrate that dividing pedestrian severity data into seven clusters helps in reducing the systematic heterogeneity of the data and to understand the hidden relationships between crash severity levels and socio-demographic, environmental, vehicle, temporal, traffic factors, and main reason for the crash. The pedestrian crash injury severity models were developed for the whole data and individual clusters, and were compared using receiver operating characteristics curve, for which results favored clustering. Overall, the study suggests that latent class clustered regression approach is suitable for reducing heterogeneity and revealing important hidden relationships in traffic safety analyses.

  14. Conversion of the dominantly ideal perturbations into a tearing mode after a sawtooth crash

    SciTech Connect

    Igochine, V. Gude, A.; Günter, S.; Lackner, K.; Yu, Q.; Barrera Orte, L.; McDermott, R. M.; Bogomolov, A.; Classen, I.; Luhmann, N. C.

    2014-11-15

    Forced magnetic reconnection is a topic of common interest in astrophysics, space science, and magnetic fusion research. The tearing mode formation process after sawtooth crashes implies the existence of this type of magnetic reconnection and is investigated in great detail in the ASDEX Upgrade tokamak. The sawtooth crash provides a fast relaxation of the core plasma temperature and can trigger a tearing mode at a neighbouring resonant surface. It is demonstrated for the first time that the sawtooth crash leads to a dominantly ideal kink mode formation at the resonant surface immediately after the sawtooth crash. Local measurements show that this kink mode transforms into a tearing mode on a much longer timescale (10{sup −3}s−10{sup −2}s) than the sawtooth crash itself (10{sup −4}s). The ideal kink mode formed after the sawtooth crash provides the driving force for magnetic reconnection and its amplitude is one of the critical parameters for the length of the transition phase from a ideal into an resistive mode. Nonlinear two fluid MHD simulations confirm these observations.

  15. Teen Crashes Declined After Massachusetts Raised Penalties For Graduated Licensing Law Restricting Night Driving.

    PubMed

    Rajaratnam, Shantha M W; Landrigan, Christopher P; Wang, Wei; Kaprielian, Rachel; Moore, Richard T; Czeisler, Charles A

    2015-06-01

    In 2007, as part of the Massachusetts graduated driver-licensing program designed to allow junior operators (ages 16½-17 years) to gain experience before receiving full licensure, stringent penalties were introduced for violating a law prohibiting unsupervised driving at night; driver education, including drowsy driving education, became mandatory; and other new restrictions and penalties began. We evaluated the impact of these changes on police-reported vehicle crash records for one year before and five years after the law's implementation in drivers ages 16-17, inclusive, and two comparison groups. We found that crash rates for the youngest drivers fell 18.6 percent, from 16.24 to 13.22 per 100 licensed drivers. For drivers ages 18-19 the rates fell by 6.7 percent (from 9.59 to 8.95 per 100 drivers), and for those ages 20 and older, the rate remained relatively constant. The incidence rate ratio for drivers ages 16-17 relative to those ages 20 and older decreased 19.1 percent for all crashes, 39.8 percent for crashes causing a fatal or incapacitating injury, and 28.8 percent for night crashes. Other states should consider implementing strict penalties for violating graduated driver-licensing laws, including restrictions on unsupervised night driving, to reduce the risk of sleep-related crashes in young people.

  16. Teen Crashes Declined After Massachusetts Raised Penalties For Graduated Licensing Law Restricting Night Driving.

    PubMed

    Rajaratnam, Shantha M W; Landrigan, Christopher P; Wang, Wei; Kaprielian, Rachel; Moore, Richard T; Czeisler, Charles A

    2015-06-01

    In 2007, as part of the Massachusetts graduated driver-licensing program designed to allow junior operators (ages 16½-17 years) to gain experience before receiving full licensure, stringent penalties were introduced for violating a law prohibiting unsupervised driving at night; driver education, including drowsy driving education, became mandatory; and other new restrictions and penalties began. We evaluated the impact of these changes on police-reported vehicle crash records for one year before and five years after the law's implementation in drivers ages 16-17, inclusive, and two comparison groups. We found that crash rates for the youngest drivers fell 18.6 percent, from 16.24 to 13.22 per 100 licensed drivers. For drivers ages 18-19 the rates fell by 6.7 percent (from 9.59 to 8.95 per 100 drivers), and for those ages 20 and older, the rate remained relatively constant. The incidence rate ratio for drivers ages 16-17 relative to those ages 20 and older decreased 19.1 percent for all crashes, 39.8 percent for crashes causing a fatal or incapacitating injury, and 28.8 percent for night crashes. Other states should consider implementing strict penalties for violating graduated driver-licensing laws, including restrictions on unsupervised night driving, to reduce the risk of sleep-related crashes in young people. PMID:26056201

  17. How the choice of safety performance function affects the identification of important crash prediction variables.

    PubMed

    Wang, Ketong; Simandl, Jenna K; Porter, Michael D; Graettinger, Andrew J; Smith, Randy K

    2016-03-01

    Across the nation, researchers and transportation engineers are developing safety performance functions (SPFs) to predict crash rates and develop crash modification factors to improve traffic safety at roadway segments and intersections. Generalized linear models (GLMs), such as Poisson or negative binomial regression, are most commonly used to develop SPFs with annual average daily traffic as the primary roadway characteristic to predict crashes. However, while more complex to interpret, data mining models such as boosted regression trees have improved upon GLMs crash prediction performance due to their ability to handle more data characteristics, accommodate non-linearities, and include interaction effects between the characteristics. An intersection data inventory of 36 safety relevant parameters for three- and four-legged non-signalized intersections along state routes in Alabama was used to study the importance of intersection characteristics on crash rate and the interaction effects between key characteristics. Four different SPFs were investigated and compared: Poisson regression, negative binomial regression, regularized generalized linear model, and boosted regression trees. The models did not agree on which intersection characteristics were most related to the crash rate. The boosted regression tree model significantly outperformed the other models and identified several intersection characteristics as having strong interaction effects. PMID:26710265

  18. An Approach to Estimate the Localized Effects of an Aircraft Crash on a Facility

    SciTech Connect

    Kimura, C; Sanzo, D; Sharirli, M

    2004-04-19

    Aircraft crashes are an element of external events required to be analyzed and documented in facility Safety Analysis Reports (SARs) and Nuclear Explosive Safety Studies (NESSs). This paper discusses the localized effects of an aircraft crash impact into the Device Assembly Facility (DAF) located at the Nevada Test Site (NTS), given that the aircraft hits the facility. This was done to gain insight into the robustness of the DAF and to account for the special features of the DAF that enhance its ability to absorb the effects of an aircraft crash. For the purpose of this paper, localized effects are considered to be only perforation or scabbing of the facility. This paper presents an extension to the aircraft crash risk methodology of Department of Energy (DOE) Standard 3014. This extension applies to facilities that may find it necessary or desirable to estimate the localized effects of an aircraft crash hit on a facility of nonuniform construction or one that is shielded in certain directions by surrounding terrain or buildings. This extension is not proposed as a replacement to the aircraft crash risk methodology of DOE Standard 3014 but rather as an alternate method to cover situations that were not considered.

  19. Crash reconstruction and injury-mechanism analysis using event data recorder technology.

    PubMed

    Donnelly, B R; Galganski, R A; Lawrence, R D; Blatt, A

    2001-01-01

    Sophisticated onboard crash-event data recorders (EDRs) that log key vehicle dynamics information can be used to improve crash reconstruction, model occupant response, study the mechanisms of injury, and estimate occupant injury probabilities in near-real time. Such an EDR was developed and utilized as part of the Automatic Collision Notification (ACN) system for the National Highway Traffic Safety Administration. This paper presents the results of a study in which the reconstruction of an actual crash was augmented using EDR/ACN-supplied three-dimensional acceleration and other data in a vehicle occupant model configured using the Articulated Total Body (ATB) computer code. ATB-generated occupant-motion imagery and body-region acceleration response information provided valuable insights that permitted crash-reconstruction specialists to ascertain the true nature of the collision and identify the probable cause of an injury suffered by one of the victims. The authors also posit that the use of EDR data from an ACN-type system as inputs to occupant crash-response modeling may be someday support crash-victim emergency medical treatment and triage.

  20. Biochar aging reduces earthworm avoidance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar, a black carbon substance produced by the pyrolysis of organic feedstocks, has been used in many soil improvement strategies ranging from nutrient addition to sequestration of C. Simple toxicity studies and laboratory preference/avoidance assays are recommended but results rarely reported. ...

  1. Avoided cost pricing: who wins

    SciTech Connect

    Einhorn, M.A.

    1985-05-30

    This article calls for a reevaluation of current Federal Energy Regulatory Commission regulations on the calculation of avoided cost rates for sales of power to utilities by small producers in the light of market conditions not contemplated at the time of the regulations' adoption. 8 references.

  2. Avoiding plagiarism in academic writing.

    PubMed

    Anderson, Irene

    Plagiarism means taking the work of another and presenting it as one's own, resulting in potential upset for the original author and disrepute for the professions involved. This article aims to explore the issue of plagiarism and some mechanisms for detection and avoidance.

  3. Anti-terrorist vehicle crash impact energy absorbing barrier

    DOEpatents

    Swahlan, David J.

    1989-01-01

    An anti-terrorist vehicle crash barrier includes side support structures, crushable energy absorbing aluminum honeycomb modules, and an elongated impact-resistant beam extending between, and at its opposite ends through vertical guideways defined by, the side support structures. An actuating mechanism supports the beam at its opposite ends for movement between a lowered barrier-withdrawn position in which a traffic-supporting side of the beam is aligned with a traffic-bearing surface permitting vehicular traffic between the side support structures and over the beam, and a raised barrier-imposed position in which the beam is aligned with horizontal guideways defined in the side support structures above the traffic-bearing surface, providing an obstruction to vehicular traffic between the side support structures. The beam is movable rearwardly in the horizontal guideways with its opposite ends disposed transversely therethrough upon being impacted at its forward side by an incoming vehicle. The crushable modules are replaceably disposed in the horizontal guideways between aft ends thereof and the beam. The beam, replaceable modules, side support structures and actuating mechanism are separate and detached from one another such that the beam and replaceable modules are capable of coacting to disable and stop an incoming vehicle without causing structural damage to the side support structures and actuating mechanism.

  4. Children in crashes: mechanisms of injury and restraint systems

    PubMed Central

    Lapner, Peter C.; McKay, Morag; Howard, Andrew; Gardner, Bill; German, Alan; Letts, Mervyn

    2001-01-01

    Objectives To explore the levels of protection offered to children involved in motor vehicle collisions. Design A joint study by the Children’s Hospital of Eastern Ontario (CHEO) and Transport Canada, Ottawa, conducted in 2 phases: retrospective from 1990 to 1997 and prospective from 1998 to 2000. Setting CHEO, a university affiliated tertiary care centre. Patients Children admitted to CHEO between 1990 and 2000 with spinal trauma due to motor vehical crashes (MVCs). Phase 1 of the study involved analysis, in a series of 45 children after MVAs, by location of spinal injury versus belt type. Phase 2 was a prospective study of 22 children injured in 15 MVAs. Interventions A biomechanical assessment of the vehicle and its influence on the injuries sustained. Main outcome measures The nature and extent of the injuries sustained, and the vehicle dynamics and associated occupant kinematics. Results The odds ratio of sustaining a spinal injury while wearing a 2-point belt versus a 3-point belt was 24 (95% confidence interval 2.0–2.45, p < 0.1), indicating a much higher incidence with a lap belt than a shoulder strap. Conclusions Proper seat-belt restraint reduces the morbidity in children involved in MVCs. Children under the age of 12 years should not be front-seat passengers until the sensitivity of air bags has been improved. Three-point pediatric seat belts should be available for family automobiles to reduce childhood trauma in MVCs. PMID:11764879

  5. Geographic variations in mortality from motor vehicle crashes.

    PubMed

    Baker, S P; Whitfield, R A; O'Neill, B

    1987-05-28

    Using a new technique to study the mortality associated with motor vehicle crashes, we calculated population-based death rates of occupants of motor vehicles during the period 1979 through 1981 and mapped them according to county for the 48 contiguous states of the United States. Mortality was highest in counties of low population density (r = 0.57; P less than 0.0001) and was also inversely correlated with per capita income (r = 0.23; P less than 0.0001). Death rates varied more than 100-fold; for example, Esmeralda County, Nevada, with 0.2 residents per square mile (2.6 km2), had a death rate of 558 per 100,000 population, as compared with Manhattan, New York, with 64,000 residents per square mile and a death rate of 2.5 per 100,000. Differences in road characteristics, travel speeds, seat-belt use, types of vehicles, and availability of emergency care may have been major contributors to these relations.

  6. Homogenization of Vehicle Fleet Frontal Crash Pulses from 2000–2010

    PubMed Central

    Locey, Caitlin M.; Garcia-Espana, J. Felipe; Toh, Akira; Belwadi, Aditya; Arbogast, Kristy B.; Maltese, Matthew R.

    2012-01-01

    Full-scale vehicle crash tests are performed globally to assess vehicle structure and restraint system performance. The crash pulse, captured by accelerometers mounted within the occupant compartment, measures the motion of the vehicle during the impact event. From an occupant’s perspective, the crash pulse is the inertial event to which the vehicle’s restraint systems must respond in order to mitigate the forces and accelerations that act on a passenger, and thus reduce injury risk. The objective of this study was to quantify the characteristics of crash pulses for different vehicle types in the contemporary North American fleet, and delineate current trends in crash pulse evolution. NHTSA and Transport Canada crash test databases were queried for full-frontal rigid barrier crash tests of passenger vehicles model year 2000–2010 with impact angle equaling zero degrees. Acceleration-time histories were analyzed for all accelerometers attached to the vehicle structure within the occupant compartment. Custom software calculated the following crash pulse characteristics (CPCs): peak deceleration, time of peak deceleration, onset rate, pulse duration, and change in velocity. Vehicle body types were classified by adapting the Highway Loss Data Institute (HLDI) methodology, and vehicles were assigned a generation start year in place of model year in order to more accurately represent structural change over time. 1094 vehicle crash tests with 2795 individual occupant compartment-mounted accelerometers were analyzed. We found greater peak decelerations and and shorter pulse durations across multiple vehicle types in newer model years as compared to older. For midsize passenger cars, large passenger cars, and large SUVs in 56 km/h rigid barrier tests, maximum deceleration increased by 0.40, 0.96, and 1.57 g/year respectively, and pulse duration decreased by 0.74, 1.87, and 2.51 ms/year. We also found that the crash pulse characteristics are becoming more homogeneous in

  7. Differences in Factors Affecting Various Crash Types with High Numbers of Fatalities and Injuries in China

    PubMed Central

    Wang, Kai; He, Jie; Ding, Jianxun; Shi, Qin; Wang, Changjun; Li, Pingfan

    2016-01-01

    Objectives Road traffic crashes that involve very high numbers of fatalities and injuries arouse public concern wherever they occur. In China, there are two categories of such crashes: a crash that results in 10–30 fatalities, 50–100 serious injuries or a total cost of 50–100 million RMB ($US8-16m) is a “serious road traffic crash” (SRTC), while a crash that is even more severe or costly is a “particularly serious road traffic crash” (PSRTC). The aim of this study is to identify the main factors affecting different types of these crashes (single-vehicle, head-on, rear-end and side impact) with the ultimate goal of informing prevention activities and policies. Methods Detailed descriptions of the SRTCs and PSRTCs that occurred from 2007 to 2014 were collected from the database “In-depth Investigation and Analysis System for Major Road Traffic Crashes” (IIASMRTC), which is maintained by the Traffic Management Research Institute of the Ministry of Public Security of China (TMRI). 18 main risk factors, which were categorized into four areas (participant, vehicle, road and environment-related) were chosen as potential independent variables for the multinomial logistic regression analysis. Comparisons were made among the single-vehicle, head-on, rear-end and side impact crashes in terms of factors affecting crash occurrence. Findings Five risk factors were significant for the six multinomial logistic regression models, which were location, vertical alignment, roadside safety rating, driver distraction and overloading of cargo. It was indicated that intersections were more likely to have side impact SRTCs and PSRTCs, especially with poor visibility at night. Overloaded freight vehicles were more likely to be involved in a rear-end crash than other freight vehicles. Driver distraction is an important risk factor for head-on crashes, while vertical alignment and roadside safety rating are positively associated with single-vehicle crashes. Conclusion Based

  8. Homogenization of vehicle fleet frontal crash pulses from 2000-2010.

    PubMed

    Locey, Caitlin M; Garcia-Espana, J Felipe; Toh, Akira; Belwadi, Aditya; Arbogast, Kristy B; Maltese, Matthew R

    2012-01-01

    Full-scale vehicle crash tests are performed globally to assess vehicle structure and restraint system performance. The crash pulse, captured by accelerometers mounted within the occupant compartment, measures the motion of the vehicle during the impact event. From an occupant's perspective, the crash pulse is the inertial event to which the vehicle's restraint systems must respond in order to mitigate the forces and accelerations that act on a passenger, and thus reduce injury risk. The objective of this study was to quantify the characteristics of crash pulses for different vehicle types in the contemporary North American fleet, and delineate current trends in crash pulse evolution. NHTSA and Transport Canada crash test databases were queried for full-frontal rigid barrier crash tests of passenger vehicles model year 2000-2010 with impact angle equaling zero degrees. Acceleration-time histories were analyzed for all accelerometers attached to the vehicle structure within the occupant compartment. Custom software calculated the following crash pulse characteristics (CPCs): peak deceleration, time of peak deceleration, onset rate, pulse duration, and change in velocity. Vehicle body types were classified by adapting the Highway Loss Data Institute (HLDI) methodology, and vehicles were assigned a generation start year in place of model year in order to more accurately represent structural change over time. 1094 vehicle crash tests with 2795 individual occupant compartment-mounted accelerometers were analyzed. We found greater peak decelerations and and shorter pulse durations across multiple vehicle types in newer model years as compared to older. For midsize passenger cars, large passenger cars, and large SUVs in 56 km/h rigid barrier tests, maximum deceleration increased by 0.40, 0.96, and 1.57 g/year respectively, and pulse duration decreased by 0.74, 1.87, and 2.51 ms/year. We also found that the crash pulse characteristics are becoming more homogeneous in the

  9. US Commercial Air Tour Crashes, 2000–2011: Burden, Fatal Risk Factors, and FIA Score Validation

    PubMed Central

    Ballard, Sarah-Blythe; Beaty, Leland P.; Baker, Susan P.

    2013-01-01

    Introduction This study provides new public health data concerning the US commercial air tour industry. Risk factors for fatality in air tour crashes were analyzed to determine the value of the FIA score in predicting fatal outcomes. Methods Using the Federal Aviation Administration’s (FAA) General Aviation and Air Taxi Survey and National Transportation Safety Board data, the incidence of commercial air tour crashes from 2000 through 2010 was calculated. Fatality risk factors for crashes occurring from 2000 through 2011 were analyzed using regression methods. The FIA score, Li and Baker’s fatality risk index, was validated using receiver operating characteristic (ROC) curves. Results The industry-wide commercial air tour crash rate was 2.7 per 100,000 flight hours. The incidence rates of Part 91 and 135 commercial air tour crashes were 3.4 and 2.3 per 100,000 flight hours, respectively (relative risk [RR] 1.5, 95% confidence interval [CI] 1.1–2.1, P=0.015). Of the 152 air tour crashes that occurred from 2000 through 2011, 30 (20%) involved at least one fatality and, on average, 3.5 people died per fatal crash. Fatalities were associated with three major risk factors: fire (Adjusted odds ratio [AOR] 5.1, 95% CI 1.5–16.7, P=0.008), instrument meteorological conditions (AOR 5.4, 95% CI 1.1–26.4, P=0.038), and off-airport location (AOR 7.2, 95% CI 1.6–33.2, P=0.011). The area under the FIA Score’s ROC curve was 0.79 (95% CI 0.71–0.88). Discussion Commercial air tour crash rates were high relative to similar commercial aviation operations. Disparities between Part 91 and 135 air tour crash rates reflect regulatory disparities that require FAA action. The FIA Score appeared to be a valid measurement of fatal risk in air tour crashes. The FIA should prioritize interventions that address the three major risk factors identified by this study. PMID:23631935

  10. Projecting Fatalities in Crashes Involving Older Drivers, 2000–2025, CRADA No. ORNL98-0500 Final Report

    SciTech Connect

    Hu, Patricia S.; Jones, Donald W.; Reuscher, Timothy; Schmoyer, Richard S.; Truett, Lorena F.

    2000-04-01

    At the turn of the century – the 20th century that is – the median age in the United States was under 30 years; America was 60% rural in nature; and there were only 36 highway fatalities all year. As we leave the 20th century behind, the route into the 21st century is very different. “Intelligent” cars speed down multi-lane “smart” highways in a nation that is 75% urban. According to the Federal Highway Administration’s Highway Statistics, there are 28,000 times more vehicles on the road in 2000 than there were in 1900, and these vehicles travel about 2.6 trillion miles each year. Annual fatalities resulting from highway crashes have also increased – by over 1100%. We see other changes as well. The face of America is changing. It is growing older. In 2025, persons 65 and over will make up 18.5% of the total population. The number of persons aged 85 and over is increasing more rapidly than any other age group. More importantly, the elderly are taking more trips, driving further, and continuing to drive much later in life. These conditions lead to concerns about traffic safety. Although the elderly are healthier and drive safer cars than they did just two decades ago, their frailty makes them more susceptible to injury than younger persons involved in traffic crashes of the same severity. In addition, visual, physical, and cognitive skills, all of which contribute to driving abilities, decrease with advancing age. The familiar “U”-shaped curve depicting the rate of fatalities per vehicle miles traveled, shows that the elderly experience a higher highway fatality rate than any other age group except teenagers. While the overall number of highway fatalities has decreased regularly since 1972, the number of fatalities of elderly travelers has continued to increase steadily. This increase is cause for concern for both the elderly driver and for other persons on the roads who migh tbe placed in danger through crashes involving elderly drivers.

  11. Predicting Crashes Using Traffic Offences. A Meta-Analysis that Examines Potential Bias between Self-Report and Archival Data

    PubMed Central

    af Wåhlberg, Anders; Freeman, James; Watson, Barry; Watson, Angela

    2016-01-01

    Background Traffic offences have been considered an important predictor of crash involvement, and have often been used as a proxy safety variable for crashes. However the association between crashes and offences has never been meta-analysed and the population effect size never established. Research is yet to determine the extent to which this relationship may be spuriously inflated through systematic measurement error, with obvious implications for researchers endeavouring to accurately identify salient factors predictive of crashes. Methodology and Principal Findings Studies yielding a correlation between crashes and traffic offences were collated and a meta-analysis of 144 effects drawn from 99 road safety studies conducted. Potential impact of factors such as age, time period, crash and offence rates, crash severity and data type, sourced from either self-report surveys or archival records, were considered and discussed. After weighting for sample size, an average correlation of r = .18 was observed over the mean time period of 3.2 years. Evidence emerged suggesting the strength of this correlation is decreasing over time. Stronger correlations between crashes and offences were generally found in studies involving younger drivers. Consistent with common method variance effects, a within country analysis found stronger effect sizes in self-reported data even controlling for crash mean. Significance The effectiveness of traffic offences as a proxy for crashes may be limited. Inclusion of elements such as independently validated crash and offence histories or accurate measures of exposure to the road would facilitate a better understanding of the factors that influence crash involvement. PMID:27128093

  12. A model to identify high crash road segments with the dynamic segmentation method.

    PubMed

    Boroujerdian, Amin Mirza; Saffarzadeh, Mahmoud; Yousefi, Hassan; Ghassemian, Hassan

    2014-12-01

    Currently, high social and economic costs in addition to physical and mental consequences put road safety among most important issues. This paper aims at presenting a novel approach, capable of identifying the location as well as the length of high crash road segments. It focuses on the location of accidents occurred along the road and their effective regions. In other words, due to applicability and budget limitations in improving safety of road segments, it is not possible to recognize all high crash road segments. Therefore, it is of utmost importance to identify high crash road segments and their real length to be able to prioritize the safety improvement in roads. In this paper, after evaluating deficiencies of the current road segmentation models, different kinds of errors caused by these methods are addressed. One of the main deficiencies of these models is that they can not identify the length of high crash road segments. In this paper, identifying the length of high crash road segments (corresponding to the arrangement of accidents along the road) is achieved by converting accident data to the road response signal of through traffic with a dynamic model based on the wavelet theory. The significant advantage of the presented method is multi-scale segmentation. In other words, this model identifies high crash road segments with different lengths and also it can recognize small segments within long segments. Applying the presented model into a real case for identifying 10-20 percent of high crash road segment showed an improvement of 25-38 percent in relative to the existing methods.

  13. Drinking, Driving, and Crashing: A Traffic-Flow Model of Alcohol-Related Motor Vehicle Accidents*

    PubMed Central

    Gruenewald, Paul J.; Johnson, Fred W.

    2010-01-01

    Objective: This study examined the influence of on-premise alcohol-outlet densities and of drinking-driver densities on rates of alcohol-related motor vehicle crashes. A traffic-flow model is developed to represent geographic relationships between residential locations of drinking drivers, alcohol outlets, and alcohol-related motor vehicle crashes. Method: Cross-sectional and time-series cross-sectional spatial analyses were performed using data collected from 144 geographic units over 4 years. Data were obtained from archival and survey sources in six communities. Archival data were obtained within community areas and measured activities of either the resident population or persons visiting these communities. These data included local and highway traffic flow, locations of alcohol outlets, population density, network density of the local roadway system, and single-vehicle nighttime (SVN) crashes. Telephone-survey data obtained from residents of the communities were used to estimate the size of the resident drinking and driving population. Results: Cross-sectional analyses showed that effects relating on-premise densities to alcohol-related crashes were moderated by highway traffic flow. Depending on levels of highway traffic flow, 10% greater densities were related to 0% to 150% greater rates of SVN crashes. Time-series cross-sectional analyses showed that changes in the population pool of drinking drivers and on-premise densities interacted to increase SVN crash rates. Conclusions: A simple traffic-flow model can assess the effects of on-premise alcohol-outlet densities and of drinking-driver densities as they vary across communities to produce alcohol-related crashes. Analyses based on these models can usefully guide policy decisions on the siting of on-premise alcohol outlets. PMID:20230721

  14. Cyclists and drivers in road interactions: A comparison of perceived crash risk.

    PubMed

    Chaurand, Nadine; Delhomme, Patricia

    2013-01-01

    Today's increase in the number of cyclists has triggered a change in the interactions to be handled by road users. However, few studies have investigated crash risk perceived by cyclists interacting with other users, and few have compared cyclists' and drivers' perceptions of crash risk in bike-car interactions, the most dangerous situation for cyclists. Our aims here are to study perceived crash risk (no matter the seriousness of the crash) in six common road situations during which cyclist crashes are frequent and also to study cyclists' and drivers' perceived risk in bike-car interactions, in comparison to other interaction types (cyclist vs. cyclist and driver vs. driver). We predicted that perceived risk of being involved in a crash during a particular interaction would be greater when in interaction with a car than with a bike, and that drivers would perceive more risk than cyclists would. We also predicted that perceived risk would decrease with drivers' and cyclists' experience of their transportation mode and their perceived control over the interaction situation. We ran an online survey on two samples, experienced cyclists (N=336) and non-cyclist car drivers (N=92). Participants evaluated their personal risk - as cyclists or as drivers - of being involved in a road crash if they were in an interaction with a bike or a car for each of six risky road situations. Experience was measured in terms of years of vehicle driving and driven km; perceived control was measured in terms of perceived skill and responsibility for the risky behavior. The results validated our hypotheses: perceived risk was higher for car drivers than for cyclists and for interacting with a car than with a bike. The implications of these results for interventions to improve road safety for both cyclists and car drivers are discussed. PMID:23021420

  15. Crash reduction following installation of centerline rumble strips on rural two-lane roads.

    PubMed

    Persaud, Bhagwant N; Retting, Richard A; Lyon, Craig A

    2004-11-01

    Rural two-lane roads generally lack physical measures such as wide medians or barriers to separate opposing traffic flows. As a result, a major crash problem on these roads involves vehicles crossing the centerline and either sideswiping or striking the front ends of opposing vehicles. These types of opposing-direction crashes account for about 20% all fatal crashes on rural two-lane roads and result in about 4,500 fatalities annually in the US. The present study evaluated a potential engineering countermeasure for such crashes-installation of rumble strips along the centerlines of undivided rural two-lane roads to alert distracted, fatigued, or speeding motorists whose vehicles are about to cross the centerlines and encroach into opposing traffic lanes. Data were analyzed for approximately 210 miles of treated roads in seven states before and after installation of centerline rumble strips. An empirical Bayes before-after procedure was employed to properly account for regression to the mean while normalizing for differences in traffic volume and other factors between the before and after periods. Overall results indicated significant reductions for all injury crashes combined (14%, 95% confidence interval (95% CI) = 5-23%) as well as for frontal and opposing-direction sideswipe injury crashes (25%, 95% CI = 6-44%)--the primary target of centerline rumble strips. In light of their effectiveness and relatively low installation costs, consideration should be given to installing centerline rumble strips more widely on rural two-lane roads to reduce the risk of frontal and opposing-direction sideswipe crashes.

  16. Using recurrence plot analysis to distinguish between endogenous and exogenous stock market crashes

    NASA Astrophysics Data System (ADS)

    Guhathakurta, Kousik; Bhattacharya, Basabi; Chowdhury, A. Roy

    2010-05-01

    Recurrence Plots are graphical tools based on Phase Space Reconstruction. Recurrence Quantification Analysis (RQA) is a statistical quantification of RPs. RP and RQA are good at working with non-stationarity and noisy data, in detecting changes in data behavior, in particular in detecting breaks, like a phase transition and in informing about other dynamic properties of a time series. Endogenous Stock Market Crashes have been modeled as phase changes in recent times. Motivated by this, we have used RP and RQA techniques for detecting critical regimes preceding an endogenous crash seen as a phase transition and hence give an estimation of the initial bubble time. We have used a new method for computing RQA measures with confidence intervals. We have also used the techniques on a known exogenous crash to see if the RP reveals a different story or not. The analysis is made on Nifty, Hong Kong AOI and Dow Jones Industrial Average, taken over a time span of about 3 years for the endogenous crashes. Then the RPs of all time series have been observed, compared and discussed. All the time series have been first transformed into the classical momentum divided by the maximum Xmax of the time series over the time window which is considered in the specific analysis. RPs have been plotted for each time series, and RQA variables have been computed on different epochs. Our studies reveal that, in the case of an endogenous crash, we have been able to identify the bubble, while in the case of exogenous crashes the plots do not show any such pattern, thus helping us in identifying such crashes.

  17. Causation mechanisms in car-to-vulnerable road user crashes: implications for active safety systems.

    PubMed

    Habibovic, Azra; Davidsson, Johan

    2012-11-01

    Vulnerable road users (VRUs), such as pedestrians and bicyclists, are often involved in crashes with passenger cars. One way to prevent these crashes is to deploy active safety systems that support the car drivers and/or VRUs. However, to develop such systems, a thorough understanding of crash causation mechanisms is required. The aim of this study is to identify crash causation mechanisms from the perspective of the VRUs, and to explore the implications of these mechanisms for the development of active safety systems. Data originate from the European project SafetyNet, where 995 crashes were in-depth investigated using the SafetyNet Accident Causation System (SNACS). To limit the scope, this study analyzed only intersection crashes involving VRUs. A total of 56 VRU crashes were aggregated. Results suggest that, while 30% of the VRUs did not see the conflict car due to visual obstructions in the traffic environment, 70% of the VRUs saw the car before the collision, but still misunderstood the traffic situation and/or made an inadequate plan of action. An important implication that follows from this is that, while detection of cars is clearly an issue that needs to be addressed, it is even more important to help the VRUs to correctly understand traffic situation (e.g., does the driver intend to slow down, and if s/he does, is it to let the VRU cross or for some other reason?). The former issue suggests a role for various cooperative active safety systems, as the obstacles are generally impenetrable with regular sensors. The latter issue is less straightforward. While various systems can be proposed, such as providing gap size estimation and reducing the car speed variability, the functional merits of each such a system need to be further investigated. PMID:23036427

  18. Investigating the relationship between run-off-the-road crash frequency and traffic flow through different functional forms.

    PubMed

    Roque, Carlos; Cardoso, João Lourenço

    2014-02-01

    Crash prediction models play a major role in highway safety analysis. These models can be used for various purposes, such as predicting the number of road crashes or establishing relationships between these crashes and different covariates. However, the appropriate choice for the functional form of these models is generally not discussed in research literature on road safety. In case of run-off-the-road crashes, empirical evidence and logical considerations lead to conclusion that the relationship between expected frequency and traffic flow is not monotonously increasing.

  19. Opportunities for injury reduction in US frontal crashes: an overview by structural engagement, vehicle class, and occupant age.

    PubMed

    Samaha, Randa Radwan; Prasad, Priya; Nix, Lilly

    2013-11-01

    An overview NASS study of US frontal crashes was performed to investigate crash involvement, driver injury distributions and rates in airbag equipped vehicles by vehicle class and structural engagement. Frontal crash bins were based on taxonomy of structural engagement, i.e., Full Engagement, Offset, Between Rails and Corner impact crashes. A new classification of Corner impacts included frontal small overlap impacts with side damage as coded by NASS CDS. Belted drivers of two age groups, between 16 and 50 and over 50 years old, were considered. Vehicles were grouped into light and heavy passenger cars and lights trucks, and vans. A method to identify and address overly influential NASS weights was developed based on considerations of weighting factor statistics. The new taxonomy, with an expanded definition of corner impacts, allowed a more comprehensive classification of frontal crash modes. Results highlight the need to address upper extremities injuries and to better address lower extremities injuries for both the younger and older drivers. For all body regions studied, the vast majority of all serious and moderate injuries occurred in Full Engagement and Offset crash modes for both the younger and older drivers. Corner impacts, which have been the focus of recent research and testing programs, are the smallest contributors to serious and moderate injuries in frontal crashes. Greater opportunities to mitigate injuries in frontal crashes for vehicles have been shown to exist in lower speed full frontal and offset crash modes.

  20. Advanced Air Bag Technology Assessment

    NASA Technical Reports Server (NTRS)

    Phen, R. L.; Dowdy, M. W.; Ebbeler, D. H.; Kim. E.-H.; Moore, N. R.; VanZandt, T. R.

    1998-01-01

    As a result of the concern for the growing number of air-bag-induced injuries and fatalities, the administrators of the National Highway Traffic Safety Administration (NHTSA) and the National Aeronautics and Space Administration (NASA) agreed to a cooperative effort that "leverages NHTSA's expertise in motor vehicle safety restraint systems and biomechanics with NASAs position as one of the leaders in advanced technology development... to enable the state of air bag safety technology to advance at a faster pace..." They signed a NASA/NHTSA memorandum of understanding for NASA to "evaluate air bag to assess advanced air bag performance, establish the technological potential for improved technology (smart) air bag systems, and identify key expertise and technology within the agency (i.e., NASA) that can potentially contribute significantly to the improved effectiveness of air bags." NASA is committed to contributing to NHTSAs effort to: (1) understand and define critical parameters affecting air bag performance; (2) systematically assess air bag technology state of the art and its future potential; and (3) identify new concepts for air bag systems. The Jet Propulsion Laboratory (JPL) was selected by NASA to respond to the memorandum of understanding by conducting an advanced air bag technology assessment. JPL analyzed the nature of the need for occupant restraint, how air bags operate alone and with safety belts to provide restraint, and the potential hazards introduced by the technology. This analysis yielded a set of critical parameters for restraint systems. The researchers examined data on the performance of current air bag technology, and searched for and assessed how new technologies could reduce the hazards introduced by air bags while providing the restraint protection that is their primary purpose. The critical parameters which were derived are: (1) the crash severity; (2) the use of seat belts; (3) the physical characteristics of the occupants; (4) the