Taxi 'sugar daddies' and taxi queens: male taxi driver attitudes regarding transactional relationships in the Western Cape, South Africa.

PubMed

Potgieter, Cheryl; Strebel, Anna; Shefer, Tamara; Wagner, Claire

2012-11-01

Media reports are emerging on the phenomenon of young girls who travel with older mini-bus taxi drivers, and who are thought to have sex with the drivers in exchange for gifts and money. The extent to which such relationships might facilitate unsafe sexual practices and increased risks for both the men and the young women, often referred to as taxi queens, remains an important question in the light of the current challenges of HIV/AIDS in sub-Saharan Africa. However, very little research has been undertaken on this issue, especially regarding the perceptions and experiences of taxi drivers. Thus this paper aims to provide some preliminary findings on taxi drivers' attitudes and beliefs about taxi queens and their relationships with taxi drivers. A 22-item questionnaire was administered to 223 male taxi drivers in two regions in the Western Cape Province, South Africa. Taxi drivers in this study largely saw the relationship between taxi drivers and the young girls who ride with them as providing status for both the girls and drivers, and there seemed to be recognition of the transactional nature of the relationship between taxi drivers and taxi queens. The stigmatisation of young girls who ride with taxi drivers was evident. Drivers had knowledge and awareness of the risks of unsafe sex and supported condom use, although there appeared to be some uncertainty and confusion about the likelihood of HIV infection between drivers and girls. While taxi drivers recognised the role of alcohol in relationships with young girls, they seemed to deny that the abuse of drugs was common. The study highlights a number of key areas that need to be explored with men in the taxi industry, in order to address risk behaviours for both taxi drivers and the girls who ride with them.

Taxi driver speeding: Who, when, where and how? A comparative study between Shanghai and New York City.

PubMed

Huang, Yizhe; Sun, Daniel Jian; Tang, Juanyu

2018-04-03

The 3 objectives of this study are to (1) identify the driving style characteristics of taxi drivers in Shanghai and New York City (NYC) using taxi Global Positioning System (GPS) data and make a comparative analysis; (2) explore the influence of different driving style characteristics on the frequency of speeding (who and how?) and (3) explore the influence of driving style characteristics, road attributes, and environmental factors on the speeding rate (when, where, and how?) Methods: This study proposes a driver-road-environment identification (DREI) method to investigate the determinant factors of taxi speeding violations. Driving style characteristics, together with road and environment variables, were obtained based on the GPS data and auxiliary spatiotemporal data in Shanghai and NYC. The daily working hours of taxi drivers in Shanghai (18.6 h) was far more than in NYC (8.5 h). The average occupancy speed of taxi drivers in Shanghai (21.3 km/h) was similar to that of NYC (20.3 km/h). Speeders in both cities had shorter working hours and longer daily driving distance than other taxi drivers, though their daily income was similar. Speeding drivers routinely took long-distance trips (>10 km) and preferred relatively faster routes. Length of segments (1.0-1.5 km) and good traffic condition were associated with high speeding rates, whereas central business district area and secondary road were associated with low speeding rates. Moreover, many speeding violations were identified between 4:00 a.m. and 7:00 a.m. in both Shanghai and NYC and the worst period was between 5:00 a.m. and 6:00 a.m. in both cities. Characteristics of drivers, road attributes, and environment variables should be considered together when studying driver speeding behavior. Findings of this study may assist in stipulating relevant laws and regulations such as stricter offense monitoring in the early morning, long segment supervision, shift rule regulation, and working hour restriction to

Contributing factors to vehicle to vehicle crash frequency and severity under rainfall.

PubMed

Jung, Soyoung; Jang, Kitae; Yoon, Yoonjin; Kang, Sanghyeok

2014-09-01

This study combined vehicle to vehicle crash frequency and severity estimations to examine factor impacts on Wisconsin highway safety in rainy weather. Because of data deficiency, the real-time water film depth, the car-following distance, and the vertical curve grade were estimated with available data sources and a GIS analysis to capture rainy weather conditions at the crash location and time. Using a negative binomial regression for crash frequency estimation, the average annual daily traffic per lane, the interaction between the posted speed limit change and the existence of an off-ramp, and the interaction between the travel lane number change and the pavement surface material change were found to increase the likelihood of vehicle to vehicle crashes under rainfall. However, more average daily rainfall per month and a wider left shoulder were identified as factors that decrease the likelihood of vehicle to vehicle crashes. In the crash severity estimation using the multinomial logit model that outperformed the ordered logit model, the travel lane number, the interaction between the travel lane number and the slow grade, the deep water film, and the rear-end collision type were more likely to increase the likelihood of injury crashes under rainfall compared with crashes involving only property damage. As an exploratory data analysis, this study provides insight into potential strategies for rainy weather highway safety improvement, specifically, the following weather-sensitive strategies: road design and ITS implementation for drivers' safety awareness under rainfall. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

Modeling taxi demand with GPS data from taxis and transit.

DOT National Transportation Integrated Search

2014-07-01

Identifying factors that influence taxi demand is very important for understanding where and when people use taxis and how taxi demand relates to the availability and quality of transit service. This study used a large set of global positioning syste...

Speed, speed variation and crash relationships for urban arterials.

PubMed

Wang, Xuesong; Zhou, Qingya; Quddus, Mohammed; Fan, Tianxiang; Fang, Shou'en

2018-04-01

Speed and speed variation are closely associated with traffic safety. There is, however, a dearth of research on this subject for the case of urban arterials in general, and in the context of developing nations. In downtown Shanghai, the traffic conditions in each direction are very different by time of day, and speed characteristics during peak hours are also greatly different from those during off-peak hours. Considering that traffic demand changes with time and in different directions, arterials in this study were divided into one-way segments by the direction of flow, and time of day was differentiated and controlled for. In terms of data collection, traditional fixed-based methods have been widely used in previous studies, but they fail to capture the spatio-temporal distributions of speed along a road. A new approach is introduced to estimate speed variation by integrating spatio-temporal speed fluctuation of a single vehicle with speed differences between vehicles using taxi-based high frequency GPS data. With this approach, this paper aims to comprehensively establish a relationship between mean speed, speed variation and traffic crashes for the purpose of formulating effective speed management measures, specifically using an urban dataset. From a total of 234 one-way road segments from eight arterials in Shanghai, mean speed, speed variation, geometric design features, traffic volume, and crash data were collected. Because the safety effects of mean speed and speed variation may vary at different segment lengths, arterials with similar signal spacing density were grouped together. To account for potential correlations among these segments, a hierarchical Poisson log-normal model with random effects was developed. Results show that a 1% increase in mean speed on urban arterials was associated with a 0.7% increase in total crashes, and larger speed variation was also associated with increased crash frequency. Copyright © 2018 Elsevier Ltd. All rights

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

Understanding taxi travel patterns

NASA Astrophysics Data System (ADS)

Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

2016-09-01

Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

Random parameter models of interstate crash frequencies by severity, number of vehicles involved, collision and location type.

PubMed

Venkataraman, Narayan; Ulfarsson, Gudmundur F; Shankar, Venky N

2013-10-01

A nine-year (1999-2007) continuous panel of crash histories on interstates in Washington State, USA, was used to estimate random parameter negative binomial (RPNB) models for various aggregations of crashes. A total of 21 different models were assessed in terms of four ways to aggregate crashes, by: (a) severity, (b) number of vehicles involved, (c) crash type, and by (d) location characteristics. The models within these aggregations include specifications for all severities (property damage only, possible injury, evident injury, disabling injury, and fatality), number of vehicles involved (one-vehicle to five-or-more-vehicle), crash type (sideswipe, same direction, overturn, head-on, fixed object, rear-end, and other), and location types (urban interchange, rural interchange, urban non-interchange, rural non-interchange). A total of 1153 directional road segments comprising of the seven Washington State interstates were analyzed, yielding statistical models of crash frequency based on 10,377 observations. These results suggest that in general there was a significant improvement in log-likelihood when using RPNB compared to a fixed parameter negative binomial baseline model. Heterogeneity effects are most noticeable for lighting type, road curvature, and traffic volume (ADT). Median lighting or right-side lighting are linked to increased crash frequencies in many models for more than half of the road segments compared to both-sides lighting. Both-sides lighting thereby appears to generally lead to a safety improvement. Traffic volume has a random parameter but the effect is always toward increasing crash frequencies as expected. However that the effect is random shows that the effect of traffic volume on crash frequency is complex and varies by road segment. The number of lanes has a random parameter effect only in the interchange type models. The results show that road segment-specific insights into crash frequency occurrence can lead to improved design policy and

Exploring the effects of roadway characteristics on the frequency and severity of head-on crashes: case studies from Malaysian federal roads.

PubMed

Hosseinpour, Mehdi; Yahaya, Ahmad Shukri; Sadullah, Ahmad Farhan

2014-01-01

Head-on crashes are among the most severe collision types and of great concern to road safety authorities. Therefore, it justifies more efforts to reduce both the frequency and severity of this collision type. To this end, it is necessary to first identify factors associating with the crash occurrence. This can be done by developing crash prediction models that relate crash outcomes to a set of contributing factors. This study intends to identify the factors affecting both the frequency and severity of head-on crashes that occurred on 448 segments of five federal roads in Malaysia. Data on road characteristics and crash history were collected on the study segments during a 4-year period between 2007 and 2010. The frequency of head-on crashes were fitted by developing and comparing seven count-data models including Poisson, standard negative binomial (NB), random-effect negative binomial, hurdle Poisson, hurdle negative binomial, zero-inflated Poisson, and zero-inflated negative binomial models. To model crash severity, a random-effect generalized ordered probit model (REGOPM) was used given a head-on crash had occurred. With respect to the crash frequency, the random-effect negative binomial (RENB) model was found to outperform the other models according to goodness of fit measures. Based on the results of the model, the variables horizontal curvature, terrain type, heavy-vehicle traffic, and access points were found to be positively related to the frequency of head-on crashes, while posted speed limit and shoulder width decreased the crash frequency. With regard to the crash severity, the results of REGOPM showed that horizontal curvature, paved shoulder width, terrain type, and side friction were associated with more severe crashes, whereas land use, access points, and presence of median reduced the probability of severe crashes. Based on the results of this study, some potential countermeasures were proposed to minimize the risk of head-on crashes. Copyright �

Yellow taxis have fewer accidents than blue taxis because yellow is more visible than blue.

PubMed

Ho, Teck-Hua; Chong, Juin Kuan; Xia, Xiaoyu

2017-03-21

Is there a link between the color of a taxi and how many accidents it has? An analysis of 36 mo of detailed taxi, driver, and accident data (comprising millions of data points) from the largest taxi company in Singapore suggests that there is an explicit link. Yellow taxis had 6.1 fewer accidents per 1,000 taxis per month than blue taxis, a 9% reduction in accident probability. We rule out driver difference as an explanatory variable and empirically show that because yellow taxis are more noticeable than blue taxis-especially when in front of another vehicle, and in street lighting-other drivers can better avoid hitting them, directly reducing the accident rate. This finding can play a significant role when choosing colors for public transportation and may save lives as well as millions of dollars.

Inferring Passenger Denial Behavior of Taxi Drivers from Large-Scale Taxi Traces.

PubMed

Zhang, Sihai; Wang, Zhiyang

2016-01-01

How to understand individual human actions is a fundamental question to modern science, which drives and incurs many social, technological, racial, religious and economic phenomena. Human dynamics tries to reveal the temporal pattern and internal mechanism of human actions in letter or electronic communications, from the perspective of continuous interactions among friends or acquaintances. For interactions between stranger to stranger, taxi industry provide fruitful phenomina and evidence to investigate the action decisions. In fact, one striking disturbing events commonly reported in taxi industry is passenger refusing or denial, whose reasons vary, including skin color, blind passenger, being a foreigner or too close destination, religion reasons and anti specific nationality, so that complaints about taxi passenger refusing have to be concerned and processed carefully by local governments. But more universal factors for this phenomena are of great significance, which might be fulfilled by big data research to obtain novel insights in this question. In this paper, we demonstrate the big data analytics application in revealing novel insights from massive taxi trace data, which, for the first time, validates the passengers denial in taxi industry and estimates the denial ratio in Beijing city. We first quantify the income differentiation facts among taxi drivers. Then we find out that choosing the drop-off places also contributes to the high income for taxi drivers, compared to the previous explanation of mobility intelligence. Moreover, we propose the pick-up, drop-off and grid diversity concepts and related diversity analysis suggest that, high income taxi drivers will deny passengers in some situations, so as to choose the passengers' destination they prefer. Finally we design an estimation method for denial ratio and infer that high income taxi drivers will deny passengers with 8.52% likelihood in Beijing. Our work exhibits the power of big data analysis in

Inferring Passenger Denial Behavior of Taxi Drivers from Large-Scale Taxi Traces

PubMed Central

Zhang, Sihai; Wang, Zhiyang

2016-01-01

How to understand individual human actions is a fundamental question to modern science, which drives and incurs many social, technological, racial, religious and economic phenomena. Human dynamics tries to reveal the temporal pattern and internal mechanism of human actions in letter or electronic communications, from the perspective of continuous interactions among friends or acquaintances. For interactions between stranger to stranger, taxi industry provide fruitful phenomina and evidence to investigate the action decisions. In fact, one striking disturbing events commonly reported in taxi industry is passenger refusing or denial, whose reasons vary, including skin color, blind passenger, being a foreigner or too close destination, religion reasons and anti specific nationality, so that complaints about taxi passenger refusing have to be concerned and processed carefully by local governments. But more universal factors for this phenomena are of great significance, which might be fulfilled by big data research to obtain novel insights in this question. In this paper, we demonstrate the big data analytics application in revealing novel insights from massive taxi trace data, which, for the first time, validates the passengers denial in taxi industry and estimates the denial ratio in Beijing city. We first quantify the income differentiation facts among taxi drivers. Then we find out that choosing the drop-off places also contributes to the high income for taxi drivers, compared to the previous explanation of mobility intelligence. Moreover, we propose the pick-up, drop-off and grid diversity concepts and related diversity analysis suggest that, high income taxi drivers will deny passengers in some situations, so as to choose the passengers’ destination they prefer. Finally we design an estimation method for denial ratio and infer that high income taxi drivers will deny passengers with 8.52% likelihood in Beijing. Our work exhibits the power of big data analysis in

Differences in passenger car and large truck involved crash frequencies at urban signalized intersections: an exploratory analysis.

PubMed

Dong, Chunjiao; Clarke, David B; Richards, Stephen H; Huang, Baoshan

2014-01-01

The influence of intersection features on safety has been examined extensively because intersections experience a relatively large proportion of motor vehicle conflicts and crashes. Although there are distinct differences between passenger cars and large trucks-size, operating characteristics, dimensions, and weight-modeling crash counts across vehicle types is rarely addressed. This paper develops and presents a multivariate regression model of crash frequencies by collision vehicle type using crash data for urban signalized intersections in Tennessee. In addition, the performance of univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression models in establishing the relationship between crashes, traffic factors, and geometric design of roadway intersections is investigated. Bayesian methods are used to estimate the unknown parameters of these models. The evaluation results suggest that the MVPLN model possesses most of the desirable statistical properties in developing the relationships. Compared to the UVPLN and MVP models, the MVPLN model better identifies significant factors and predicts crash frequencies. The findings suggest that traffic volume, truck percentage, lighting condition, and intersection angle significantly affect intersection safety. Important differences in car, car-truck, and truck crash frequencies with respect to various risk factors were found to exist between models. The paper provides some new or more comprehensive observations that have not been covered in previous studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Motorcycle safety among motorcycle taxi drivers and nonoccupational motorcyclists in developing countries: A case study of Maoming, South China.

PubMed

Wu, Connor Y H; Loo, Becky P Y

2016-01-01

An increasing number of motorcycle taxis have been involved in traffic crashes in many developing countries. This study examines the characteristics of both motorcycle taxi drivers and nonoccupational motorcyclists, investigates the risks they pose to road safety, and provides recommendations to minimize their risks. Based on the data collected from a questionnaire survey of 867 motorcycle taxi drivers and 2,029 nonoccupational motorcyclists in Maoming, South China, comparisons were made to analyze differences of personal attributes, attitudes toward road safety, and self-reported behavior of the 2 groups. Results of the chi-square tests show that not only motorcycle taxi drivers but also nonoccupational motorcyclists in Maoming held poor attitudes toward road safety and both groups reported unsafe driving behavior. There is much room for improving local road safety education among all motorcyclists in Maoming. Yet, motorcycle taxi drivers were more likely to pose road safety risks than nonoccupational motorcyclists under some circumstances, such as speeding late at night or early in the morning, not requiring passengers to wear helmets, and running a red light. The results of the binary logistic regression model show that possessing a vehicle license for a motorcycle or not was the common significant predictor for unsafe driving behavior of motorcycle taxi drivers and nonoccupational motorcyclists. Therefore, enforcement against all motorcyclists not showing vehicle licenses for their motorcycles should be stepped up. Motorcycle safety is largely poor in Maoming. Therefore, efforts to improve motorcycle safety should be strengthened by targeting not only motorcycle taxi drivers but also nonoccupational motorcyclists.

Yellow taxis have fewer accidents than blue taxis because yellow is more visible than blue

PubMed Central

Ho, Teck-Hua; Chong, Juin Kuan; Xia, Xiaoyu

2017-01-01

Is there a link between the color of a taxi and how many accidents it has? An analysis of 36 mo of detailed taxi, driver, and accident data (comprising millions of data points) from the largest taxi company in Singapore suggests that there is an explicit link. Yellow taxis had 6.1 fewer accidents per 1,000 taxis per month than blue taxis, a 9% reduction in accident probability. We rule out driver difference as an explanatory variable and empirically show that because yellow taxis are more noticeable than blue taxis—especially when in front of another vehicle, and in street lighting—other drivers can better avoid hitting them, directly reducing the accident rate. This finding can play a significant role when choosing colors for public transportation and may save lives as well as millions of dollars. PMID:28265081

Multivariate random-parameters zero-inflated negative binomial regression model: an application to estimate crash frequencies at intersections.

PubMed

Dong, Chunjiao; Clarke, David B; Yan, Xuedong; Khattak, Asad; Huang, Baoshan

2014-09-01

Crash data are collected through police reports and integrated with road inventory data for further analysis. Integrated police reports and inventory data yield correlated multivariate data for roadway entities (e.g., segments or intersections). Analysis of such data reveals important relationships that can help focus on high-risk situations and coming up with safety countermeasures. To understand relationships between crash frequencies and associated variables, while taking full advantage of the available data, multivariate random-parameters models are appropriate since they can simultaneously consider the correlation among the specific crash types and account for unobserved heterogeneity. However, a key issue that arises with correlated multivariate data is the number of crash-free samples increases, as crash counts have many categories. In this paper, we describe a multivariate random-parameters zero-inflated negative binomial (MRZINB) regression model for jointly modeling crash counts. The full Bayesian method is employed to estimate the model parameters. Crash frequencies at urban signalized intersections in Tennessee are analyzed. The paper investigates the performance of MZINB and MRZINB regression models in establishing the relationship between crash frequencies, pavement conditions, traffic factors, and geometric design features of roadway intersections. Compared to the MZINB model, the MRZINB model identifies additional statistically significant factors and provides better goodness of fit in developing the relationships. The empirical results show that MRZINB model possesses most of the desirable statistical properties in terms of its ability to accommodate unobserved heterogeneity and excess zero counts in correlated data. Notably, in the random-parameters MZINB model, the estimated parameters vary significantly across intersections for different crash types. Copyright © 2014 Elsevier Ltd. All rights reserved.

Non-linear effects of the built environment on automobile-involved pedestrian crash frequency: A machine learning approach.

PubMed

Ding, Chuan; Chen, Peng; Jiao, Junfeng

2018-03-01

Although a growing body of literature focuses on the relationship between the built environment and pedestrian crashes, limited evidence is provided about the relative importance of many built environment attributes by accounting for their mutual interaction effects and their non-linear effects on automobile-involved pedestrian crashes. This study adopts the approach of Multiple Additive Poisson Regression Trees (MAPRT) to fill such gaps using pedestrian collision data collected from Seattle, Washington. Traffic analysis zones are chosen as the analytical unit. The effects of various factors on pedestrian crash frequency investigated include characteristics the of road network, street elements, land use patterns, and traffic demand. Density and the degree of mixed land use have major effects on pedestrian crash frequency, accounting for approximately 66% of the effects in total. More importantly, some factors show clear non-linear relationships with pedestrian crash frequency, challenging the linearity assumption commonly used in existing studies which employ statistical models. With various accurately identified non-linear relationships between the built environment and pedestrian crashes, this study suggests local agencies to adopt geo-spatial differentiated policies to establish a safe walking environment. These findings, especially the effective ranges of the built environment, provide evidence to support for transport and land use planning, policy recommendations, and road safety programs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Predicting motorcycle crash injury severity using weather data and alternative Bayesian multivariate crash frequency models.

PubMed

Cheng, Wen; Gill, Gurdiljot Singh; Sakrani, Taha; Dasu, Mohan; Zhou, Jiao

2017-11-01

Motorcycle crashes constitute a very high proportion of the overall motor vehicle fatalities in the United States, and many studies have examined the influential factors under various conditions. However, research on the impact of weather conditions on the motorcycle crash severity is not well documented. In this study, we examined the impact of weather conditions on motorcycle crash injuries at four different severity levels using San Francisco motorcycle crash injury data. Five models were developed using Full Bayesian formulation accounting for different correlations commonly seen in crash data and then compared for fitness and performance. Results indicate that the models with serial and severity variations of parameters had superior fit, and the capability of accurate crash prediction. The inferences from the parameter estimates from the five models were: an increase in the air temperature reduced the possibility of a fatal crash but had a reverse impact on crashes of other severity levels; humidity in air was not observed to have a predictable or strong impact on crashes; the occurrence of rainfall decreased the possibility of crashes for all severity levels. Transportation agencies might benefit from the research results to improve road safety by providing motorcyclists with information regarding the risk of certain crash severity levels for special weather conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparison of freeway median crash frequency, severity, and barrier strike outcomes by median barrier type.

PubMed

Russo, Brendan J; Savolainen, Peter T

2018-08-01

Median-crossover crashes are among the most hazardous events that can occur on freeways, often resulting in severe or fatal injuries. The primary countermeasure to reduce the occurrence of such crashes is the installation of a median barrier. When installation of a median barrier is warranted, transportation agencies are faced with the decision among various alternatives including concrete barriers, beam guardrail, or high-tension cable barriers. Each barrier type differs in terms of its deflection characteristics upon impact, the required installation and maintenance costs, and the roadway characteristics (e.g., median width) where installation would be feasible. This study involved an investigation of barrier performance through an in-depth analysis of crash frequency and severity data from freeway segments where high-tension cable, thrie-beam, and concrete median barriers were installed. A comprehensive manual review of crash reports was conducted to identify crashes in which a vehicle left the roadway and encroached into the median. This review also involved an examination of crash outcomes when a barrier strike occurred, which included vehicle containment, penetration, or re-direction onto the travel lanes. The manual review of crash reports provided critical supplementary information through narratives and diagrams not normally available through standard fields on police crash report forms. Statistical models were estimated to identify factors that affect the frequency, severity, and outcomes of median-related crashes, with particular emphases on differences between segments with varying median barrier types. Several roadway-, traffic-, and environmental-related characteristics were found to affect these metrics, with results varying across the different barrier types. The results of this study provide transportation agencies with important guidance as to the in-service performance of various types of median barrier. Copyright © 2018 Elsevier Ltd. All rights

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Shared-Ride Taxi System Requirements Study

DOT National Transportation Integrated Search

1979-05-01

Shared-ride taxi (SRT) is different from the exclusive-ride taxi (ERT) in that the taxi may be shared by unrelated passengers with different origins/destinations. By simultaneously serving more than one passenger, SRT may improve vehicle productivity...

TaxiCom 95: International Survey of Leading Innovational Taxi Communications and Operations Approaches

DOT National Transportation Integrated Search

1995-08-01

TaxiCom '95 is an update and extension of "Taxi-Based Paratransit : Technology/Operation Packages in Europe," a technical survey prepared by : EcoPlan in 1985 and distributed by the U.S. Department of : Transportation/Federal Transit Administration's...

U.S. Civil Air Show Crashes, 1993 to 2013: Burden, Fatal Risk Factors, and Evaluation of a Risk Index for Aviation Crashes.

PubMed

Ballard, Sarah-Blythe; Osorio, Victor B

2015-01-01

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.

Effect of free distribution of safety equipment on usage among motorcycle-taxi drivers in Tanzania--A cluster randomised controlled trial.

PubMed

Sumner, Steven A; Pallangyo, Anthony J; Reddy, Elizabeth A; Maro, Venance; Pence, Brian W; Lynch, Catherine; Turner, Elizabeth L; Egger, Joseph R; Thielman, Nathan M

2014-11-01

Deaths due to road traffic injuries, particularly motorcycle crashes, have increased rapidly in many African nations and context-specific strategies to improve preventative behaviours are needed. Although adhering to conspicuity measures by wearing reflective safety vests is a highly effective crash prevention strategy and mandated by law among motorcycle-taxi drivers in some African countries, actual use is currently low. We aimed to test whether eliminating cost-barriers through the provision of free reflective, fluorescent motorcycle safety vests would lead to increased utilisation among a high-risk population of motorcycle-taxi drivers in Tanzania. A cluster randomised controlled trial was conducted among 180 motorcycle-taxi drivers. Participants randomised to the intervention arm (90) received free, reflective, fluorescent vests; participants randomised to the control arm (90) did not receive free vests. Participants' use of reflective vests was then observed on city streets over a three month period and differential uptake was estimated using mixed-effects logistic regression. Baseline use of reflective vests was 3.3% in both arms. Seventy-nine drivers in the intervention arm and 82 drivers in the control arm were observed during follow-up. The average proportion of observations during which motorcycle drivers were using a reflective vest was 9.5% in the intervention arm, compared to 2.0% in the control arm (odds ratio: 5.5, 95% confidence interval: 1.1-26.9, p-value: 0.04). Although distribution of free reflective vests led to a statistically significant increase in vest usage, the absolute increase was modest. Additional strategies beyond removing economic barriers are important to augment adherence to road safety behaviours for injury prevention. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modeling level of urban taxi services using neural network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, J.; Wong, S.C.; Tong, C.O.

1999-05-01

This paper is concerned with the modeling of the complex demand-supply relationship in urban taxi services. A neural network model is developed, based on a taxi service situation observed in the urban area of Hong Kong. The input consists of several exogenous variables including number of licensed taxis, incremental charge of taxi fare, average occupied taxi journey time, average disposable income, and population and customer price index; the output consists of a set of endogenous variables including daily taxi passenger demand, passenger waiting time, vacant taxi headway, average percentage of occupied taxis, taxi utilization, and average taxi waiting time. Comparisonsmore » of the estimation accuracy are made between the neural network model and the simultaneous equations model. The results show that the neural network-based macro taxi model can obtain much more accurate information of the taxi services than the simultaneous equations model does. Although the data set used for training the neural network is small, the results obtained thus far are very encouraging. The neural network model can be used as a policy tool by regulator to assist with the decisions concerning the restriction over the number of taxi licenses and the fixing of the taxi fare structure as well as a range of service quality control.« less

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

Assessment of crash fire hazard of LH sub 2 fueled aircraft

NASA Technical Reports Server (NTRS)

Brewer, G. D.; Wittlin, G.; Versaw, E. F.; Parmley, R.; Cima, R.; Walther, E. G.

1981-01-01

The relative safety of passengers in LH2 - fueled aircraft, as well as the safety of people in areas surrounding a crash scene, has been evaluated in an analytical study. Four representative circumstances were postulated involving a transport aircraft in which varying degrees of severity of damage were sustained. Potential hazard to the passengers and to the surroundings posed by the spilled fuel was evaluated for each circumstance. Corresponding aircraft fueled with liquid methane, Jet A, and JP-4 were also studied in order to make comparisons of the relative safety. The four scenarios which were used to provide a basis for the evaluation included: (1) a small fuel leak internal to the aircraft, (2) a survivable crash in which a significant quantity of fuel is spilled in a radial pattern as a result of impact with a stationary object while taxiing at fairly low speed, (3) a survivable crash in which a significant quantity of fuel is spilled in an axial pattern as a result of impact during landing, and (4) a non-survivable crash in which a massive fuel spill occurs instantaneously.

Crash sequence based risk matrix for motorcycle crashes.

PubMed

Wu, Kun-Feng; Sasidharan, Lekshmi; Thor, Craig P; Chen, Sheng-Yin

2018-04-05

Considerable research has been conducted related to motorcycle and other powered-two-wheeler (PTW) crashes; however, it always has been controversial among practitioners concerning with types of crashes should be first targeted and how to prioritize resources for the implementation of mitigating actions. Therefore, there is a need to identify types of motorcycle crashes that constitute the greatest safety risk to riders - most frequent and most severe crashes. This pilot study seeks exhibit the efficacy of a new approach for prioritizing PTW crash causation sequences as they relate to injury severity to better inform the application of mitigating countermeasures. To accomplish this, the present study constructed a crash sequence-based risk matrix to identify most frequent and most severe motorcycle crashes in an attempt to better connect causes and countermeasures of PTW crashes. Although the frequency of each crash sequence can be computed from crash data, a crash severity model is needed to compare the levels of crash severity among different crash sequences, while controlling for other factors that also have effects on crash severity such drivers' age, use of helmet, etc. The construction of risk matrix based on crash sequences involve two tasks: formulation of crash sequence and the estimation of a mixed-effects (ME) model to adjust the levels of severities for each crash sequence to account for other crash contributing factors that would have an effect on the maximum level of crash severity in a crash. Three data elements from the National Automotive Sampling System - General Estimating System (NASS-GES) data were utilized to form a crash sequence: critical event, crash types, and sequence of events. A mixed-effects model was constructed to model the severity levels for each crash sequence while accounting for the effects of those crash contributing factors on crash severity. A total of 8039 crashes involving 8208 motorcycles occurred during 2011 and 2013 were

The application of algorithm in taxi security system

NASA Astrophysics Data System (ADS)

Luo, Chengyu

2017-08-01

With the booming of the society and economy today, Taxis and private cars have gradually become one of the most popular tools in transportation for their low price and convenience. However, because of the breakdown in the security system, a few accidents occurred due to the illegal taxi. The unreliable security management has attributed to the lack of trust in taxi companies and relevant regulatory authorities, which considered to be the reason why people are worried about it. Accordingly, we put forward a design for a taxi security system, making use of modern technology such as NFC, iBeacon, GPS combined with algorithms, automatically recognize the taxi we take, and reflecting basic information of taxi and driver on our mobile phone.

Full Bayes Poisson gamma, Poisson lognormal, and zero inflated random effects models: Comparing the precision of crash frequency estimates.

PubMed

Aguero-Valverde, Jonathan

2013-01-01

In recent years, complex statistical modeling approaches have being proposed to handle the unobserved heterogeneity and the excess of zeros frequently found in crash data, including random effects and zero inflated models. This research compares random effects, zero inflated, and zero inflated random effects models using a full Bayes hierarchical approach. The models are compared not just in terms of goodness-of-fit measures but also in terms of precision of posterior crash frequency estimates since the precision of these estimates is vital for ranking of sites for engineering improvement. Fixed-over-time random effects models are also compared to independent-over-time random effects models. For the crash dataset being analyzed, it was found that once the random effects are included in the zero inflated models, the probability of being in the zero state is drastically reduced, and the zero inflated models degenerate to their non zero inflated counterparts. Also by fixing the random effects over time the fit of the models and the precision of the crash frequency estimates are significantly increased. It was found that the rankings of the fixed-over-time random effects models are very consistent among them. In addition, the results show that by fixing the random effects over time, the standard errors of the crash frequency estimates are significantly reduced for the majority of the segments on the top of the ranking. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

Geographic region, weather, pilot age, and air carrier crashes: a case-control study.

PubMed

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

2009-04-01

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. 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. 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 ladjusted 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 0.60, 95% CI 0.37-0.96). Neither pilot age nor total flight time were significantly associated with the risk of air carrier crashes. 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.

Health assessment of taxi drivers in the city of Tshwane.

PubMed

Ramukumba, Tendani S; Mathikhi, Makwena S

2016-11-30

Taxi driving seems to be a strenuous occupation. There was evidence-based paucity of literature on health assessment of taxi drivers. Meanwhile taxi drivers of South Africa were burdened by communicable and non-communicable diseases including high-level exposure to injuries and criminal attacks. Health assessment of this cohort group enables mitigation to engage in appropriation of relevant interventions related to the occupational needs of taxi drivers. The objective of the study was to conduct health assessment of taxi drivers in the city of Tshwane to identify health risk factors. An exploratory, descriptive and quantitative survey was conducted and anthropometric measurements of blood pressure, body mass index and waist circumference were monitored and recorded on a convenience sample of 69 taxi drivers in Tshwane Municipality. Consent was sought from individual taxi drivers who participated in the study, while taxi rank queue marshals assisted with smooth running of the process. Data were gathered using a questionnaire. Data analysis was performed using statistical STATA II with the assistance of a statistician. The study found that taxi drivers were obese, hypertensive, had type II diabetes-related risk factors, including unhealthy life style practices. The results indicate that the general health of taxi drivers impacts their occupation. The findings implicate that the health status of taxi operators in Tshwane was a serious concern and urgent concerted effort is needed to engage in lifestyle modification of taxi drivers. The need for health promotion and formalised occupational health services was recommended.

Energy Taxis Is the Dominant Behavior in Azospirillum brasilense

PubMed Central

Alexandre, Gladys; Greer, Suzanne E.; Zhulin, Igor B.

2000-01-01

Energy taxis encompasses aerotaxis, phototaxis, redox taxis, taxis to alternative electron acceptors, and chemotaxis to oxidizable substrates. The signal for this type of behavior is originated within the electron transport system. Energy taxis was demonstrated, as a part of an overall behavior, in several microbial species, but it did not appear as the dominant determinant in any of them. In this study, we show that most behavioral responses proceed through this mechanism in the alpha-proteobacterium Azospirillum brasilense. First, chemotaxis to most chemoeffectors typical of the azospirilla habitat was found to be metabolism dependent and required a functional electron transport system. Second, other energy-related responses, such as aerotaxis, redox taxis, and taxis to alternative electron acceptors, were found in A. brasilense. Finally, a mutant lacking a cytochrome c oxidase of the cbb3 type was affected in chemotaxis, redox taxis, and aerotaxis. Altogether, the results indicate that behavioral responses to most stimuli in A. brasilense are triggered by changes in the electron transport system. PMID:11029423

Taxi Cab Syndrome: A Review of the Extensive Genitourinary Pathology Experienced by Taxi Cab Drivers and What We Can Do to Help

PubMed Central

Mass, Alon Y; Goldfarb, David S; Shah, Ojas

2014-01-01

This review consolidates knowledge regarding the extensive genitourinary pathology experienced by taxi cab drivers. Taxi cab, livery, truck, and other drivers all objectively and subjectively may have more voiding dysfunction, infertility, urolithiasis, bladder cancer, and urinary infections as compared with nonprofessional drivers; this is called taxi cab syndrome. Together with governmental and medical assistance, simple interventions—such as education, the addition of taxi relief stations, and possibly the use of sanitary urinary collection devices—to curb the progression of genitourinary disease in taxi drivers should be prospectively studied. It is postulated that many of these interventions may also benefit other groups of occupationally related infrequent voiders. PMID:25337038

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.

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

The impact of rainfall on the temporal and spatial distribution of taxi passengers

PubMed Central

Zhang, Yong; Gao, Liangpeng; Geng, Nana; Li, Xuefeng

2017-01-01

This paper focuses on the impact of rainfall on the temporal and spatial distribution of taxi passengers. The main objective is to provide guidance for taxi scheduling on rainy days. To this end, we take the occupied and empty states of taxis as units of analysis. By matching a taxi's GPS data to its taximeter data, we can obtain the taxi's operational time and the taxi driver's income from every unit of analysis. The ratio of taxi operation time to taxi drivers' income is used to measure the quality of taxi passengers. The research results show that the spatio-temporal evolution of urban taxi service demand differs based on rainfall conditions and hours of operation. During non-rush hours, taxi demand in peripheral areas is significantly reduced under increasing precipitation conditions, whereas during rush hours, the demand for highly profitable taxi services steadily increases. Thus, as an intelligent response for taxi operations and dispatching, taxi services should guide cruising taxis to high-demand regions to increase their service time and ride opportunities. PMID:28873430

49 CFR 37.29 - Private entities providing taxi service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Private entities providing taxi service. 37.29... INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.29 Private entities providing taxi service. (a) Providers of taxi service are subject to the requirements of this part for private entities primarily...

49 CFR 37.29 - Private entities providing taxi service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false Private entities providing taxi service. 37.29... INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.29 Private entities providing taxi service. (a) Providers of taxi service are subject to the requirements of this part for private entities primarily...

Standardization of databases for AMDB taxi routing functions

NASA Astrophysics Data System (ADS)

Pschierer, C.; Sindlinger, A.; Schiefele, J.

2010-04-01

Input, management, and display of taxi routes on airport moving map displays (AMM) have been covered in various studies in the past. The demonstrated applications are typically based on Aerodrome Mapping Databases (AMDB). Taxi routing functions require specific enhancements, typically in the form of a graph network with nodes and edges modeling all connectivities within an airport, which are not supported by the current AMDB standards. Therefore, the data schemas and data content have been defined specifically for the purpose and test scenarios of these studies. A standardization of the data format for taxi routing information is a prerequisite for turning taxi routing functions into production. The joint RTCA/EUROCAE special committee SC-217, responsible for updating and enhancing the AMDB standards DO-272 [1] and DO-291 [2], is currently in the process of studying different alternatives and defining reasonable formats. Requirements for taxi routing data are primarily driven by depiction concepts for assigned and cleared taxi routes, but also by database size and the economic feasibility. Studied concepts are similar to the ones described in the GDF (geographic data files) specification [3], which is used in most car navigation systems today. They include - A highly aggregated graph network of complex features - A modestly aggregated graph network of simple features - A non-explicit topology of plain AMDB taxi guidance line elements This paper introduces the different concepts and their advantages and disadvantages.

Commercial bus crashes in North Carolina 1995-1999

DOT National Transportation Integrated Search

2000-04-01

Tables and figures are shown to depict a statistical representation of commercial bus crashes in North Carolina. Information displayed includes crash frequency, crashes by county, accident severity, time of day, month of the year, class of roadway, r...

Analyzing crash frequency in freeway tunnels: A correlated random parameters approach.

PubMed

Hou, Qinzhong; Tarko, Andrew P; Meng, Xianghai

2018-02-01

The majority of past road safety studies focused on open road segments while only a few focused on tunnels. Moreover, the past tunnel studies produced some inconsistent results about the safety effects of the traffic patterns, the tunnel design, and the pavement conditions. The effects of these conditions therefore remain unknown, especially for freeway tunnels in China. The study presented in this paper investigated the safety effects of these various factors utilizing a four-year period (2009-2012) of data as well as three models: 1) a random effects negative binomial model (RENB), 2) an uncorrelated random parameters negative binomial model (URPNB), and 3) a correlated random parameters negative binomial model (CRPNB). Of these three, the results showed that the CRPNB model provided better goodness-of-fit and offered more insights into the factors that contribute to tunnel safety. The CRPNB was not only able to allocate the part of the otherwise unobserved heterogeneity to the individual model parameters but also was able to estimate the cross-correlations between these parameters. Furthermore, the study results showed that traffic volume, tunnel length, proportion of heavy trucks, curvature, and pavement rutting were associated with higher frequencies of traffic crashes, while the distance to the tunnel wall, distance to the adjacent tunnel, distress ratio, International Roughness Index (IRI), and friction coefficient were associated with lower crash frequencies. In addition, the effects of the heterogeneity of the proportion of heavy trucks, the curvature, the rutting depth, and the friction coefficient were identified and their inter-correlations were analyzed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Safety modeling of urban arterials in Shanghai, China.

PubMed

Wang, Xuesong; Fan, Tianxiang; Chen, Ming; Deng, Bing; Wu, Bing; Tremont, Paul

2015-10-01

Traffic safety on urban arterials is influenced by several key variables including geometric design features, land use, traffic volume, and travel speeds. This paper is an exploratory study of the relationship of these variables to safety. It uses a comparatively new method of measuring speeds by extracting GPS data from taxis operating on Shanghai's urban network. This GPS derived speed data, hereafter called Floating Car Data (FCD) was used to calculate average speeds during peak and off-peak hours, and was acquired from samples of 15,000+ taxis traveling on 176 segments over 18 major arterials in central Shanghai. Geometric design features of these arterials and surrounding land use characteristics were obtained by field investigation, and crash data was obtained from police reports. Bayesian inference using four different models, Poisson-lognormal (PLN), PLN with Maximum Likelihood priors (PLN-ML), hierarchical PLN (HPLN), and HPLN with Maximum Likelihood priors (HPLN-ML), was used to estimate crash frequencies. Results showed the HPLN-ML models had the best goodness-of-fit and efficiency, and models with ML priors yielded estimates with the lowest standard errors. Crash frequencies increased with increases in traffic volume. Higher average speeds were associated with higher crash frequencies during peak periods, but not during off-peak periods. Several geometric design features including average segment length of arterial, number of lanes, presence of non-motorized lanes, number of access points, and commercial land use, were positively related to crash frequencies. Copyright © 2015 Elsevier Ltd. All rights reserved.

14 CFR 294.3 - General requirements for Canadian charter air taxi operators.

Code of Federal Regulations, 2011 CFR

2011-01-01

... air taxi operators. 294.3 Section 294.3 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General § 294.3 General requirements for Canadian charter air taxi operators. A Canadian charter air taxi operator shall...

14 CFR 294.3 - General requirements for Canadian charter air taxi operators.

Code of Federal Regulations, 2010 CFR

2010-01-01

... air taxi operators. 294.3 Section 294.3 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General § 294.3 General requirements for Canadian charter air taxi operators. A Canadian charter air taxi operator shall...

A Study Examining Compliance with the Anti-Tobacco Law Nb. 4207 Inside Taxis

PubMed Central

Öztürk, Burcu; Kosku, Hakan; Güven, İbrahim; Erdoğan, Beyza; Sarıtaş, Özge; Şanver, Tuğçe; Aslan, Dilek

2017-01-01

OBJECTIVES This observational study assessed compliance with the anti-tobacco Law Nb 4207 with regard to taxis in Çankaya district, Ankara. MATERIAL AND METHODS This descriptive study was conducted in Kızılay, Kuğulu, and Tandoğan intersections on January 18–23, 2016 between 9.00–11.00 and 14.00–16.00 hours in Ankara. Data regarding the status of the taxi (either cruising or not), smoking inside taxis, smoking status of the taxi drivers and/or clients, location of the clients in the taxi, presence of a child in the taxi, and status of the windows (open or not) were recorded using a data-gathering form. RESULTS Three thousand six hundred fifty-six taxis were evaluated, of which 79 (2.2%) taxi drivers were observed smoking. Clients were observed smoking in 17 taxis (1.3%). Ninety-four taxi drivers and/or clients (2.6%) were observed smoking. Taxi drivers smoked more frequently in the absence of a client. In addition, a smoking client influenced the taxi driver’s smoking status (p<0.001). CONCLUSION Violation of the anti-tobacco Law Nb 4207 was observed. In this regard, the number of inspections needs to be increased. Systematic training programs for the taxi drivers regarding the risks of tobacco should be a priority. Preventive studies concerning the hazards of passive smoking should be also conducted at a community level. PMID:29404168

Analyzing Impact Factors of Airport Taxiing Delay Based on Ads-B Data

NASA Astrophysics Data System (ADS)

Li, J.; Wang, X.; Xu, Y.; Li, Q.; He, C.; Li, Y.

2017-09-01

Identifying the factors that cause taxiing delay on airports is a prerequisite for optimizing aircraft taxiing schemes, and helps improve the efficiency of taxiing system. Few of current studies had quantified the potential influencing factors and further investigated their intrinsic relationship. In view of these problems, this paper uses ADS-B data to calculate taxiing delay time by restoring taxiing route and identifying key status points, and further analyzes the impact factors of airport taxiing delay by investigating the relationship between delay time and environmental data such as weather, wind, visibility etc. The case study in Guangzhou Baiyun Airport validates the effectiveness of the proposed method.

Taxi-cabs as Subjects for a Population Study

ERIC Educational Resources Information Center

Bishop, J. A.; Bradley, J. S.

1972-01-01

Describes the use of capture-recapture techniques to estimate the population of taxis in Liverpool and demonstrates the points of similarity to animal population estimation. Considers advantages of studying taxis rather than organisms in introductory studies of the techniques. (AL)

a Web-Based Platform for Visualizing Spatiotemporal Dynamics of Big Taxi Data

NASA Astrophysics Data System (ADS)

Xiong, H.; Chen, L.; Gui, Z.

2017-09-01

With more and more vehicles equipped with Global Positioning System (GPS), access to large-scale taxi trajectory data has become increasingly easy. Taxis are valuable sensors and information associated with taxi trajectory can provide unprecedented insight into many aspects of city life. But analysing these data presents many challenges. Visualization of taxi data is an efficient way to represent its distributions and structures and reveal hidden patterns in the data. However, Most of the existing visualization systems have some shortcomings. On the one hand, the passenger loading status and speed information cannot be expressed. On the other hand, mono-visualization form limits the information presentation. In view of these problems, this paper designs and implements a visualization system in which we use colour and shape to indicate passenger loading status and speed information and integrate various forms of taxi visualization. The main work as follows: 1. Pre-processing and storing the taxi data into MongoDB database. 2. Visualization of hotspots for taxi pickup points. Through DBSCAN clustering algorithm, we cluster the extracted taxi passenger's pickup locations to produce passenger hotspots. 3. Visualizing the dynamic of taxi moving trajectory using interactive animation. We use a thinning algorithm to reduce the amount of data and design a preloading strategyto load the data smoothly. Colour and shape are used to visualize the taxi trajectory data.

System dynamics model of taxi management in metropolises: Economic and environmental implications for Beijing.

PubMed

Wang, Hao; Zhang, Kai; Chen, Junhua; Wang, Zhifeng; Li, Guijun; Yang, Yuqi

2018-05-01

Taxis are an important component of urban passenger transport. Research on the daily dispatching of taxis and the utility of governmental management is important for the improvement of passenger travel, taxi driver income and environmental impacts. However, urban taxi management is a complex and dynamic system that is affected by many factors, and positive/negative feedback relationships and nonlinear interactions exist between each subsystem and variable. Therefore, conventional research methods can hardly depict its characteristics comprehensively. To bridge this gap, this paper develops a system dynamics model of urban taxi management, in which the empty-loaded rate and total demand are selected as key factors affecting taxi dispatching, and the impacts of taxi fares on driver income and travel demand are taken into account. After the validation of the model, taxi operations data derived from a prior analysis of origin-destination data of Beijing taxis are used as input for the model to simulate the taxi market in Beijing. Finally, economic and environmental implications are provided for the government to optimise policies on taxi management. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characteristics of the road and surrounding environment in metropolitan shopping strips: association with the frequency and severity of single-vehicle crashes.

PubMed

Stephan, Karen L; Newstead, Stuart V

2014-01-01

Modeling crash risk in urban areas is more complicated than in rural areas due to the complexity of the environment and the difficulty obtaining data to fully characterize the road and surrounding environment. Knowledge of factors that impact crash risk and severity in urban areas can be used for countermeasure development and the design of risk assessment tools for practitioners. This research aimed to identify the characteristics of the road and roadside, surrounding environment, and sociodemographic factors associated with single-vehicle crash (SVC) frequency and severity in complex urban environments, namely, strip shopping center road segments. A comprehensive evidence-based list of data required for measuring the influence of the road, roadside, and other factors on crash risk was developed. The data included a broader range of factors than those traditionally considered in accident prediction models. One hundred and forty-two strip shopping segments located on arterial roads in metropolitan Melbourne, Australia, were identified. Police-reported casualty data were used to determine how many SVC occurred on the segments between 2005 and 2009. Data describing segment characteristics were collected from a diverse range of sources; for example, administrative government databases (traffic volume, speed limit, pavement condition, sociodemographic data, liquor licensing), detailed maps, on-line image sources, and digital images of arterial roads collected for the Victorian state road authority. Regression models for count data were used to identify factors associated with SVC frequency. Logistic regression was used to determine factors associated with serious and fatal outcomes. One hundred and seventy SVC occurred on the 142 selected road segments during the 5-year study period. A range of factors including traffic exposure, road cross section (curves, presence of median), road type, requirement for sharing the road with other vehicle types (trams and bicycles

Statewide analysis of bicycle crashes : [project summary].

DOT National Transportation Integrated Search

2017-06-01

An extensive literature review was conducted to locate existing studies in four areas: (1) risk factors that affect the frequency and severity of bicycle crashes; (2) bicycle crash causes, patterns, and contributing factors; (3) network screening met...

The relative frequency of unsafe driving acts in serious traffic crashes

DOT National Transportation Integrated Search

2001-01-01

This study was conducted to determine the specific driver behaviors and unsafe driving acts that lead to crashes, and the situational, driver and vehicle characteristics associated with these behaviors. A sample of 723 crashes involving 1284 drivers ...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

Crash involvement of motor vehicles in relationship to the number and severity of traffic offenses. An exploratory analysis of Dutch traffic offenses and crash data.

PubMed

Goldenbeld, Charles; Reurings, Martine; Van Norden, Yvette; Stipdonk, Henk

2013-01-01

To establish the statistical relationship between offenses and crashes when the unit of analysis is the vehicle instead of the driver, to show the influence of the severity (e.g., minor speed offenses) on this relationship, and to research whether the form of this relationship is similar in different enforcement contexts. An exploratory analysis was conducted using Dutch traffic offense and crash data. Crash data included all police-registered crashes involving motorized and registered vehicles in 2009; offense data included all non-criminal traffic offenses registered during 2005-2009 (mostly camera detected). Together these comprise an estimated 97 percent of all traffic offenses registered in this period. The analysis was done on a level of identified vehicles rather than persons. Vehicles involved in crashes were matched to vehicles involved in traffic offenses. The offense frequency distributions of registered crash involved vehicles and a random selection of vehicles was analyzed. Two comparisons were made: (1) privately owned vehicles versus company-owned vehicles and (2) vehicles for which only minor speed offenses were registered versus vehicles for which at least one major speed offense was registered. An increase in traffic offense frequency coincides with a stronger increase in relative crash involvement. This relationship was adequately described by a power function. The slightly more than linear increase in the crash risk for vehicles with only minor speed offenses suggests that minor speed offenses (<10 km/h over the limit) contributed slightly to crashes. This relationship was unlikely to be caused by increased distance traveled only. For vehicles with at least one or more major speed violation an approximately quadratic increase of crash risk with increasing speed offense frequency was found. A comparison of Dutch and Canadian data showed a much more progressive offense-crash relationship in the Dutch data. The crash involvement of vehicles

The frequency--severity indeterminacy.

PubMed

Hauer, Ezra

2006-01-01

Nothing is known about unreported crashes; the information we have is of reported crashes only. Whether a crash gets reported depends on its severity. It follows by logic that, using only data about reported crashes, it is impossible to say whether a change or difference in crash counts reflects a change or difference in crash frequency or in crash severity. This indeterminacy has practical implications. Examples discussed are of the misattribution of over-representation in reported crashes of older drivers and of trucks to causal factors related to the frequency of crash involvement, and of misinterpretation by researchers of findings about the rollover propensity of SUVs.

A Bayesian assessment of the effect of highway bypasses in Iowa on crashes and crash rate.

PubMed

Cena, Lorenzo G; Keren, Nir; Li, Wen; Carriquiry, Alicia L; Pawlovich, Michael D; Freeman, Steven A

2011-08-01

A common contention is that the construction of highway bypasses negatively impacts the economy of local communities by reducing pass-by traffic for businesses. However, as access to specific business' account records is limited, this impact is difficult to quantify. Another common contention is that bypasses contribute to a reduction in overall crashes in the community and in the surrounding areas. Even though a large number of bypasses have been constructed in the State of Iowa over the past several years, their actual impact in terms of traffic safety has not been quantified. This study seeks answers to the following questions: (a) Are bypasses in Iowa associated with a reduction in crash frequencies and crash rates on the bypassed highway? (b) Do bypasses in Iowa introduce a reduction of overall crash frequencies and rates or do they merely shift crashes from the highways through the communities to the bypasses with no significant overall reduction? We obtained crash information from the Iowa DOT at 19 sites on which a bypass was constructed sometime during the past 23 years. We also obtained the same information at six sites used as comparison sites on which no bypasses were constructed at least until 2005. We them employed a Bayesian approach to estimating the association between the construction of the bypass and crash rates, while also accounting for other factors. The construction of bypasses in Iowa is associated with a significant increase in traffic safety both on the main road through town and on the combined main road and bypass roadway. Copyright © 2011 National Safety Council and Elsevier Ltd. All rights reserved.

Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization

PubMed Central

Niu, Liyong; Zhang, Di

2015-01-01

Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly. PMID:26236770

Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization.

PubMed

Niu, Liyong; Zhang, Di

2015-01-01

Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly.

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

Seatbelt use amongst taxi drivers in Beijing, China.

PubMed

Passmore, J; Ozanne-Smith, J

2006-09-01

Associated with explosive growth in motorization, China has the world's highest road toll with more than 100,000 deaths and 400,000 injuries annually. In response, the Chinese Government introduced the first road traffic safety law in 2003, which included mandatory use of seatbelts by drivers and front seat passengers. Noting frequent non-compliance to this seatbelt regulation by Beijing taxi drivers, the authors studied seatbelt use patterns as onboard observers in a convenience sample of 235 taxi trips. Findings indicated a low seatbelt-wearing rate among taxi drivers of 7.7%, an overt non-wearing rate of 57%, covert non-wearing of 35.3% and total non-compliance of 92.3%. As in high-income countries, adoption of proven safety strategies, including wearing safety restraints, could contribute to reducing the Chinese road toll, particularly as vehicle occupant numbers and the availability of restraints increases. Further investigation of reasons for non-compliance and pretense of wearing seatbelts is required to inform future seatbelt-wearing promotions, including attitudinal studies of taxi drivers. Seatbelt wearing rates should continue to be monitored.

Barrier-relevant crash modification factors and average costs of crashes on arterial roads in Indiana.

PubMed

Zou, Yaotian; Tarko, Andrew P

2018-02-01

The objective of this study was to develop crash modification factors (CMFs) and estimate the average crash costs applicable to a wide range of road-barrier scenarios that involved three types of road barriers (concrete barriers, W-beam guardrails, and high-tension cable barriers) to produce a suitable basis for comparing barrier-oriented design alternatives and road improvements. The intention was to perform the most comprehensive and in-depth analysis allowed by the cross-sectional method and the crash data available in Indiana. To accomplish this objective and to use the available data efficiently, the effects of barrier were estimated on the frequency of barrier-relevant (BR) crashes, the types of harmful events and their occurrence during a BR crash, and the severity of BR crash outcomes. The harmful events component added depth to the analysis by connecting the crash onset with its outcome. Further improvement of the analysis was accomplished by considering the crash outcome severity of all the individuals involved in a crash and not just drivers, utilizing hospital data, and pairing the observations with and without road barriers along same or similar road segments to better control the unobserved heterogeneity. This study confirmed that the total number of BR crashes tended to be higher where medians had installed barriers, mainly due to collisions with barriers and, in some cases, with other vehicles after redirecting vehicles back to traffic. These undesirable effects of barriers were surpassed by the positive results of reducing cross-median crashes, rollover events, and collisions with roadside hazards. The average cost of a crash (unit cost) was reduced by 50% with cable barriers installed in medians wider than 50ft. A similar effect was concluded for concrete barriers and guardrails installed in medians narrower than 50ft. The studied roadside guardrails also reduced the unit cost by 20%-30%. Median cable barriers were found to be the most effective

Opportunities for crash and injury reduction: A multiharm approach for crash data analysis.

PubMed

Mallory, Ann; Kender, Allison; Moorhouse, Kevin

2017-05-29

A multiharm approach for analyzing crash and injury data was developed for the ultimate purpose of getting a richer picture of motor vehicle crash outcomes for identifying research opportunities in crash safety. Methods were illustrated using a retrospective analysis of 69,597 occupant cases from NASS CDS from 2005 to 2015. Occupant cases were analyzed by frequency and severity of outcome: fatality, injury by Abbreviated Injury Scale (AIS), number of cases, attributable fatality, disability, and injury costs. Comparative analysis variables included precrash scenario, impact type, and injured body region. Crash and injury prevention opportunities vary depending on the search parameters. For example, occupants in rear-end crash scenarios were more frequent than in any other precrash configuration, yet there were significantly more fatalities and serious injury cases in control loss, road departure, and opposite direction crashes. Fatality is most frequently associated with head and thorax injury, and disability is primarily associated with extremity injury. Costs attributed to specific body regions are more evenly distributed, dominated by injuries to the head, thorax, and extremities but with contributions from all body regions. Though AIS 3+ can be used as a single measure of harm, an analysis based on multiple measures of harm gives a much more detailed picture of the risk presented by a particular injury or set of crash conditions. The developed methods represent a new approach to crash data mining that is expected to be useful for the identification of research priorities and opportunities for reduction of crashes and injuries. As the pace of crash safety improvement accelerates with innovations in both active and passive safety, these techniques for combining outcome measures for insights beyond fatality and serious injury will be increasingly valuable.

Comparing taxi clearance input layouts for advancements in flight deck automation for surface operations

NASA Astrophysics Data System (ADS)

Cheng, Lara W. S.

Airport moving maps (AMMs) have been shown to decrease navigation errors, increase taxiing speed, and reduce workload when they depict airport layout, current aircraft position, and the cleared taxi route. However, current technologies are limited in their ability to depict the cleared taxi route due to the unavailability of datacomm or other means of electronically transmitting clearances from ATC to the flight deck. This study examined methods by which pilots can input ATC-issued taxi clearances to support taxi route depictions on the AMM. Sixteen general aviation (GA) pilots used a touchscreen monitor to input taxi clearances using two input layouts, softkeys and QWERTY, each with and without feedforward (graying out invalid inputs). QWERTY yielded more taxi route input errors than the softkeys layout. The presence of feedforward did not produce fewer taxi route input errors than in the non-feedforward condition. The QWERTY layout did reduce taxi clearance input times relative to the softkeys layout, but when feedforward was present this effect was observed only for the longer, 6-segment taxi clearances. It was observed that with the softkeys layout, feedforward reduced input times compared to non-feedforward but only for the 4-segment clearances. Feedforward did not support faster taxi clearance input times for the QWERTY layout. Based on the results and analyses of the present study, it is concluded that for taxi clearance inputs, (1) QWERTY remain the standard for alphanumeric inputs, and (2) feedforward be investigated further, with a focus on participant preference and performance of black-gray contrast of keys.

Effects of Taxi Regulatory Revision in San Diego, California

DOT National Transportation Integrated Search

1983-05-01

Effective January 1979 the City of San Diego removed its previous ceiling on taxi licenses and began issuing 6 new taxi permits every month; in July, this limit was raised to 15. In August, the city replaced the standard rate of fare with a variable ...

Uncovering urban human mobility from large scale taxi GPS data

NASA Astrophysics Data System (ADS)

Tang, Jinjun; Liu, Fang; Wang, Yinhai; Wang, Hua

2015-11-01

Taxi GPS trajectories data contain massive spatial and temporal information of urban human activity and mobility. Taking taxi as mobile sensors, the information derived from taxi trips benefits the city and transportation planning. The original data used in study are collected from more than 1100 taxi drivers in Harbin city. We firstly divide the city area into 400 different transportation districts and analyze the origin and destination distribution in urban area on weekday and weekend. The Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm is used to cluster pick-up and drop-off locations. Furthermore, four spatial interaction models are calibrated and compared based on trajectories in shopping center of Harbin city to study the pick-up location searching behavior. By extracting taxi trips from GPS data, travel distance, time and average speed in occupied and non-occupied status are then used to investigate human mobility. Finally, we use observed OD matrix of center area in Harbin city to model the traffic distribution patterns based on entropy-maximizing method, and the estimation performance verify its effectiveness in case study.

A Mixed Integer Linear Program for Solving a Multiple Route Taxi Scheduling Problem

NASA Technical Reports Server (NTRS)

Montoya, Justin Vincent; Wood, Zachary Paul; Rathinam, Sivakumar; Malik, Waqar Ahmad

2010-01-01

Aircraft movements on taxiways at busy airports often create bottlenecks. This paper introduces a mixed integer linear program to solve a Multiple Route Aircraft Taxi Scheduling Problem. The outputs of the model are in the form of optimal taxi schedules, which include routing decisions for taxiing aircraft. The model extends an existing single route formulation to include routing decisions. An efficient comparison framework compares the multi-route formulation and the single route formulation. The multi-route model is exercised for east side airport surface traffic at Dallas/Fort Worth International Airport to determine if any arrival taxi time savings can be achieved by allowing arrivals to have two taxi routes: a route that crosses an active departure runway and a perimeter route that avoids the crossing. Results indicate that the multi-route formulation yields reduced arrival taxi times over the single route formulation only when a perimeter taxiway is used. In conditions where the departure aircraft are given an optimal and fixed takeoff sequence, accumulative arrival taxi time savings in the multi-route formulation can be as high as 3.6 hours more than the single route formulation. If the departure sequence is not optimal, the multi-route formulation results in less taxi time savings made over the single route formulation, but the average arrival taxi time is significantly decreased.

Measuring and modeling air exchange rates inside taxi cabs in Los Angeles, California

NASA Astrophysics Data System (ADS)

Shu, Shi; Yu, Nu; Wang, Yueyan; Zhu, Yifang

2015-12-01

Air exchange rates (AERs) have a direct impact on traffic-related air pollutant (TRAP) levels inside vehicles. Taxi drivers are occupationally exposed to TRAP on a daily basis, yet there is limited measurement of AERs in taxi cabs. To fill this gap, AERs were quantified in 22 representative Los Angeles taxi cabs including 10 Prius, 5 Crown Victoria, 3 Camry, 3 Caravan, and 1 Uplander under realistic driving (RD) conditions. To further study the impacts of window position and ventilation settings on taxi AERs, additional tests were conducted on 14 taxis with windows closed (WC) and on the other 8 taxis with not only windows closed but also medium fan speed (WC-MFS) under outdoor air mode. Under RD conditions, the AERs in all 22 cabs had a mean of 63 h-1 with a median of 38 h-1. Similar AERs were observed under WC condition when compared to those measured under RD condition. Under WC-MFS condition, AERs were significantly increased in all taxi cabs, when compared with those measured under RD condition. A General Estimating Equation (GEE) model was developed and the modeling results showed that vehicle model was a significant factor in determining the AERs in taxi cabs under RD condition. Driving speed and car age were positively associated with AERs but not statistically significant. Overall, AERs measured in taxi cabs were much higher than typical AERs people usually encounter in indoor environments such as homes, offices, and even regular passenger vehicles.

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

Fatality rate of pedestrians and fatal crash involvement rate of drivers in pedestrian crashes: a case study of Iran.

PubMed

Kashani, Ali Tavakoli; Besharati, Mohammad Mehdi

2017-06-01

The aim of this study was to uncover patterns of pedestrian crashes. In the first stage, 34,178 pedestrian-involved crashes occurred in Iran during a four-year period were grouped into homogeneous clusters using a clustering analysis. Next, some in-cluster and inter-cluster crash patterns were analysed. The clustering analysis yielded six pedestrian crash groups. Car/van/pickup crashes on rural roads as well as heavy vehicle crashes were found to be less frequent but more likely to be fatal compared to other crash clusters. In addition, after controlling for crash frequency in each cluster, it was found that the fatality rate of each pedestrian age group as well as the fatal crash involvement rate of each driver age group varies across the six clusters. Results of present study has some policy implications including, promoting pedestrian safety training sessions for heavy vehicle drivers, imposing limitations over elderly heavy vehicle drivers, reinforcing penalties toward under 19 drivers and motorcyclists. In addition, road safety campaigns in rural areas may be promoted to inform people about the higher fatality rate of pedestrians on rural roads. The crash patterns uncovered in this study might also be useful for prioritizing future pedestrian safety research areas.

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

Modeling work zone crash frequency by quantifying measurement errors in work zone length.

PubMed

Yang, Hong; Ozbay, Kaan; Ozturk, Ozgur; Yildirimoglu, Mehmet

2013-06-01

Work zones are temporary traffic control zones that can potentially cause safety problems. Maintaining safety, while implementing necessary changes on roadways, is an important challenge traffic engineers and researchers have to confront. In this study, the risk factors in work zone safety evaluation were identified through the estimation of a crash frequency (CF) model. Measurement errors in explanatory variables of a CF model can lead to unreliable estimates of certain parameters. Among these, work zone length raises a major concern in this analysis because it may change as the construction schedule progresses generally without being properly documented. This paper proposes an improved modeling and estimation approach that involves the use of a measurement error (ME) model integrated with the traditional negative binomial (NB) model. The proposed approach was compared with the traditional NB approach. Both models were estimated using a large dataset that consists of 60 work zones in New Jersey. Results showed that the proposed improved approach outperformed the traditional approach in terms of goodness-of-fit statistics. Moreover it is shown that the use of the traditional NB approach in this context can lead to the overestimation of the effect of work zone length on the crash occurrence. Copyright © 2013 Elsevier Ltd. All rights reserved.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mining spatiotemporal patterns of urban dwellers from taxi trajectory data

NASA Astrophysics Data System (ADS)

Mao, Feng; Ji, Minhe; Liu, Ting

2016-06-01

With the widespread adoption of locationaware technology, obtaining long-sequence, massive and high-accuracy spatiotemporal trajectory data of individuals has become increasingly popular in various geographic studies. Trajectory data of taxis, one of the most widely used inner-city travel modes, contain rich information about both road network traffic and travel behavior of passengers. Such data can be used to study the microscopic activity patterns of individuals as well as the macro system of urban spatial structures. This paper focuses on trajectories obtained from GPS-enabled taxis and their applications for mining urban commuting patterns. A novel approach is proposed to discover spatiotemporal patterns of household travel from the taxi trajectory dataset with a large number of point locations. The approach involves three critical steps: spatial clustering of taxi origin-destination (OD) based on urban traffic grids to discover potentially meaningful places, identifying threshold values from statistics of the OD clusters to extract urban jobs-housing structures, and visualization of analytic results to understand the spatial distribution and temporal trends of the revealed urban structures and implied household commuting behavior. A case study with a taxi trajectory dataset in Shanghai, China is presented to demonstrate and evaluate the proposed method.

Taxi, Jitneys and Poverty

ERIC Educational Resources Information Center

Rosenbloom, Sandi

1970-01-01

Version of the paper given at The Transportation and Poverty Conference of the American Academy of Arts and Sciences. Argues for revival of jitneys (12-14 capacity motor vehicles, operating on fixed routes, fares zone-rated) to serve ghetto residents and provide employment, too. Taxi company competition also discussed. (KG)

Analysis of Traffic Crashes Involving Pedestrians Using Big Data: Investigation of Contributing Factors and Identification of Hotspots.

PubMed

Xie, Kun; Ozbay, Kaan; Kurkcu, Abdullah; Yang, Hong

2017-08-01

This study aims to explore the potential of using big data in advancing the pedestrian risk analysis including the investigation of contributing factors and the hotspot identification. Massive amounts of data of Manhattan from a variety of sources were collected, integrated, and processed, including taxi trips, subway turnstile counts, traffic volumes, road network, land use, sociodemographic, and social media data. The whole study area was uniformly split into grid cells as the basic geographical units of analysis. The cell-structured framework makes it easy to incorporate rich and diversified data into risk analysis. The cost of each crash, weighted by injury severity, was assigned to the cells based on the relative distance to the crash site using a kernel density function. A tobit model was developed to relate grid-cell-specific contributing factors to crash costs that are left-censored at zero. The potential for safety improvement (PSI) that could be obtained by using the actual crash cost minus the cost of "similar" sites estimated by the tobit model was used as a measure to identify and rank pedestrian crash hotspots. The proposed hotspot identification method takes into account two important factors that are generally ignored, i.e., injury severity and effects of exposure indicators. Big data, on the one hand, enable more precise estimation of the effects of risk factors by providing richer data for modeling, and on the other hand, enable large-scale hotspot identification with higher resolution than conventional methods based on census tracts or traffic analysis zones. © 2017 Society for Risk Analysis.

Taxi-Out Time Prediction for Departures at Charlotte Airport Using Machine Learning Techniques

NASA Technical Reports Server (NTRS)

Lee, Hanbong; Malik, Waqar; Jung, Yoon C.

2016-01-01

Predicting the taxi-out times of departures accurately is important for improving airport efficiency and takeoff time predictability. In this paper, we attempt to apply machine learning techniques to actual traffic data at Charlotte Douglas International Airport for taxi-out time prediction. To find the key factors affecting aircraft taxi times, surface surveillance data is first analyzed. From this data analysis, several variables, including terminal concourse, spot, runway, departure fix and weight class, are selected for taxi time prediction. Then, various machine learning methods such as linear regression, support vector machines, k-nearest neighbors, random forest, and neural networks model are applied to actual flight data. Different traffic flow and weather conditions at Charlotte airport are also taken into account for more accurate prediction. The taxi-out time prediction results show that linear regression and random forest techniques can provide the most accurate prediction in terms of root-mean-square errors. We also discuss the operational complexity and uncertainties that make it difficult to predict the taxi times accurately.

Evaluation of aircraft crash hazard at Los Alamos National Laboratory facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selvage, R.D.

This report selects a method for use in calculating the frequency of an aircraft crash occurring at selected facilities at the Los Alamos National Laboratory (the Laboratory). The Solomon method was chosen to determine these probabilities. Each variable in the Solomon method is defined and a value for each variable is selected for fourteen facilities at the Laboratory. These values and calculated probabilities are to be used in all safety analysis reports and hazards analyses for the facilities addressed in this report. This report also gives detailed directions to perform aircraft-crash frequency calculations for other facilities. This will ensure thatmore » future aircraft-crash frequency calculations are consistent with calculations in this report.« less

Financial Services Advertising before and after the Crash of 1987.

ERIC Educational Resources Information Center

Everett, Stephen E.

1988-01-01

Examines institutional changes in advertising before and after the stock market "crash" of 1987 as represented in the "Wall Street Journal." Finds that financial institutions increased the frequency and size of ads after the crash. (RS)

Autonomous vehicles are cost-effective when used as taxis.

PubMed

Freedman, Isaac G; Kim, Ellen; Muennig, Peter A

2018-06-04

Autonomous vehicles (AVs) will radically re-shape the health and well-being of people in the United States in good ways and bad. We set out to estimate a reasonable time-to-adoption using cost-effectivenessmodels to estimate the point at which AVs become reasonably safe and affordable for widespread adoption. We used Waymo data (previously, Google Self-Driving Car Project) and a microsimulation model to explore projected costs and safety issues today and five years from today to get a sense of the speed of consumer adoption were AVs brought to the market. The adoption of AVs for private use was associated with an ICER of 1,396,110/QALY gained today, a figure that would decline to 173,890/QALY gained 5-years in the future. However, AV taxis are both less expensive and potentially already safer than human-piloted taxis. While AVs are not unlikely to be used a family vehicles any time soon, it would make economic sense to adopt them as taxis today. Legislation enhancing the benefits while mitigating the potential harmful health impacts of AV taxis is needed with some urgency.

Assessing and reducing fine and ultrafine particles inside Los Angeles taxis

NASA Astrophysics Data System (ADS)

Yu, Nu; Shu, Shi; Lin, Yan; Zhu, Yifang

2018-05-01

Taxi drivers and passengers are exposed to high levels of traffic-related air pollutants, but their exposures to fine (PM2.5) and ultrafine particles (UFPs) and related mitigation strategies are rarely explored. In this study, UFP and PM2.5 concentrations were monitored concurrently inside and outside of 22 taxis under different ventilation and mitigation conditions. Under realistic working conditions (no mitigation; NM), the average UFP and PM2.5 levels inside taxis were 1.46 × 104 particles/cm3 and 26 μg/m3, respectively. When the taxi ventilation was set to outside air mode and the windows kept closed, in-cabin UFP and PM2.5 concentrations are significantly associated with on-road concentrations, driving speed, and cabin air filter usage. The average in-cabin to on-roadway (I/O) ratios for UFP and PM2.5 were reduced from 0.60 to 0.75 under NM, to 0.47 and 0.52 under the most stringent mitigation strategy of keeping the windows closed and operating a high efficiency cabin air filter (WC + HECA). Among all tested taxi models, Toyota Prius exhibited the lowest UFP and PM2.5 I/O ratios under WC + HECA. Switching cabin air filters from the originally equipped manufacturer filter (OEM) to a HECA filter reduced the UFP and PM2.5 I/O ratios most effectively in Toyota Prius taxis as well.

DISPAQ: Distributed Profitable-Area Query from Big Taxi Trip Data.

PubMed

Putri, Fadhilah Kurnia; Song, Giltae; Kwon, Joonho; Rao, Praveen

2017-09-25

One of the crucial problems for taxi drivers is to efficiently locate passengers in order to increase profits. The rapid advancement and ubiquitous penetration of Internet of Things (IoT) technology into transportation industries enables us to provide taxi drivers with locations that have more potential passengers (more profitable areas) by analyzing and querying taxi trip data. In this paper, we propose a query processing system, called Distributed Profitable-Area Query ( DISPAQ ) which efficiently identifies profitable areas by exploiting the Apache Software Foundation's Spark framework and a MongoDB database. DISPAQ first maintains a profitable-area query index (PQ-index) by extracting area summaries and route summaries from raw taxi trip data. It then identifies candidate profitable areas by searching the PQ-index during query processing. Then, it exploits a Z-Skyline algorithm, which is an extension of skyline processing with a Z-order space filling curve, to quickly refine the candidate profitable areas. To improve the performance of distributed query processing, we also propose local Z-Skyline optimization, which reduces the number of dominant tests by distributing killer profitable areas to each cluster node. Through extensive evaluation with real datasets, we demonstrate that our DISPAQ system provides a scalable and efficient solution for processing profitable-area queries from huge amounts of big taxi trip data.

A classification tree based modeling approach for segment related crashes on multilane highways.

PubMed

Pande, Anurag; Abdel-Aty, Mohamed; Das, Abhishek

2010-10-01

This study presents a classification tree based alternative to crash frequency analysis for analyzing crashes on mid-block segments of multilane arterials. The traditional approach of modeling counts of crashes that occur over a period of time works well for intersection crashes where each intersection itself provides a well-defined unit over which to aggregate the crash data. However, in the case of mid-block segments the crash frequency based approach requires segmentation of the arterial corridor into segments of arbitrary lengths. In this study we have used random samples of time, day of week, and location (i.e., milepost) combinations and compared them with the sample of crashes from the same arterial corridor. For crash and non-crash cases, geometric design/roadside and traffic characteristics were derived based on their milepost locations. The variables used in the analysis are non-event specific and therefore more relevant for roadway safety feature improvement programs. First classification tree model is a model comparing all crashes with the non-crash data and then four groups of crashes (rear-end, lane-change related, pedestrian, and single-vehicle/off-road crashes) are separately compared to the non-crash cases. The classification tree models provide a list of significant variables as well as a measure to classify crash from non-crash cases. ADT along with time of day/day of week are significantly related to all crash types with different groups of crashes being more likely to occur at different times. From the classification performance of different models it was apparent that using non-event specific information may not be suitable for single vehicle/off-road crashes. The study provides the safety analysis community an additional tool to assess safety without having to aggregate the corridor crash data over arbitrary segment lengths. Copyright © 2010. Published by Elsevier Ltd.

Airport Shared-Ride Taxi Programs in New York, Chicago and Boston

DOT National Transportation Integrated Search

1987-12-01

This report summarizes the development and operation of three shared-ride taxi operations at major U.S. airports. These are: New York's LaGuardia Airport Share-A-Cab; Super Saver Taxi in Chicago; and Share-A-Cab service at Boston's Logan Airport. The...

Crashes involving farm tractors and other farm vehicles/equipment in North Carolina 1995-1999

DOT National Transportation Integrated Search

2000-04-01

Tables and figures are shown to depict a statistical representation of crashes involving farm tractors and other farm vehicles or equipment, in North Carolina. Information displayed includes crash frequency, crashes by county, accident severity, type...

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand

PubMed Central

ISHIMARU, Tomohiro; ARPHORN, Sara; JIRAPONGSUWAN, Ann

2016-01-01

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers’ CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status. PMID:27151439

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand.

PubMed

Ishimaru, Tomohiro; Arphorn, Sara; Jirapongsuwan, Ann

2016-10-08

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers' CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status.

Death and injury in aerial spraying: pre-crash, crash, and post-crash prevention strategies.

PubMed

Richter, E D; Gordon, M; Halamish, M; Gribetz, B

1981-01-01

To prevent crash-related death and injury among spray pilots, a program including pre-crash, crash and post-crash stages of intervention for aircraft, physical environment, and pilots and ground crews was proposed in accordance with a matrix of options derived from road crash epidemiology. In addition to the dangers of fixed obstacles, low-altitude runs, and heavy work schedules, work hazards included combined exposures to noise, vibration, G forces, heat stress, pesticides, and dehydration. Together, these exposures were believed to have produced slight, but crucial decreases in pilot performance, alertness and skill. For aircraft, the major pre-crash measure was cockpit air cooling, with filter technologies to prevent in-flight pesticide exposure. Crash and post-crash design changes to reduce energy transfers to the pilot's body (thermal, kinetic) were the most important recommendations, because absolute prevention of the crash event was unlikely. For the environment, pre-crash recommendations included marking fixed obstacles, such as power and telephone lines, but preferably their elimination. Other measures included drainage pits with sodium hydroxide points to neutralize parathion and prevent dispersion of parathion-containing mists. Pilot pre-crash measures (more fluid intake, biological monitoring--EMG, urinary alkyl phosphate, cholinesterase testing) required special organizational arrangements. Systematic application of options from the foregoing matrix suggest that the high risk of death and injury from aerial spraying is unnecessary.

Median barrier crash severity: some new insights.

PubMed

Hu, Wen; Donnell, Eric T

2010-11-01

Median barrier is used to prevent cross-median crashes on divided highways. Although it is well documented that crash frequencies increase after installing median barrier, little is known about median barrier crash severity outcomes. The present study estimated a nested logit model of median barrier crash severity using 5 years of data from rural divided highways in North Carolina. Vehicle, driver, roadway, and median cross-section design data were factors considered in the model. A unique aspect of the data used to estimate the model was the availability of median barrier placement and median cross-slope data, two elements not commonly included in roadway inventory data files. The estimation results indicate that collisions with a cable median barrier increase the probability of less-severe crash outcomes relative to collisions with a concrete or guardrail median barrier. Increasing the median barrier offset was associated with a lower probability of severe crash outcomes. The presence of a cable median barrier installed on foreslopes that were between 6H:1V and 10H:1V were associated with an increase in severe crash probabilities when compared to cable median barrier installations on foreslopes that were 10H:1V or flatter. 2010 Elsevier Ltd. All rights reserved.

Pre-crash scenario typology for crash avoidance research

DOT National Transportation Integrated Search

2007-04-01

This report defines a new pre-crash scenario typology for crash avoidance research based on the 2004 General Estimates System (GES) crash database, which consists of pre-crash scenarios depicting vehicle movements and dynamics as well as the critical...

Performance of basic kinematic thresholds in the identification of crash and near-crash events within naturalistic driving data.

PubMed

Perez, Miguel A; Sudweeks, Jeremy D; Sears, Edie; Antin, Jonathan; Lee, Suzanne; Hankey, Jonathan M; Dingus, Thomas A

2017-06-01

Understanding causal factors for traffic safety-critical events (e.g., crashes and near-crashes) is an important step in reducing their frequency and severity. Naturalistic driving data offers unparalleled insight into these factors, but requires identification of situations where crashes are present within large volumes of data. Sensitivity and specificity of these identification approaches are key to minimizing the resources required to validate candidate crash events. This investigation used data from the Second Strategic Highway Research Program Naturalistic Driving Study (SHRP 2 NDS) and the Canada Naturalistic Driving Study (CNDS) to develop and validate different kinematic thresholds that can be used to detect crash events. Results indicate that the sensitivity of many of these approaches can be quite low, but can be improved by selecting particular threshold levels based on detection performance. Additional improvements in these approaches are possible, and may involve leveraging combinations of different detection approaches, including advanced statistical techniques and artificial intelligence approaches, additional parameter modifications, and automation of validation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2013 CFR

2013-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Filing for registration by air taxi...

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2012 CFR

2012-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Filing for registration by air taxi...

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2014 CFR

2014-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Filing for registration by air taxi...

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2011 CFR

2011-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Filing for registration by air taxi...

Considering the effects of ambient particulate matter on the lung function of motorcycle taxi drivers in Bangkok, Thailand.

PubMed

Arphorn, Sara; Ishimaru, Tomohiro; Hara, Kunio; Mahasandana, Suwisa

2018-02-01

The motorcycle taxi drivers of Bangkok have been heavily exposed to high concentrations of PM 10 (particulate matter with an aerodynamic diameter ≤10 μm), and the impact of this on their lungs has been neither documented nor studied. This study examines the association between exposure to PM 10 and lung function decline among motorcycle taxi drivers. A cross-sectional study was conducted in Bangkok between two groups: a subject group of motorcycle taxi drivers and control group of enclosed vehicle taxi drivers. The findings of the Thailand Pollution Control Department were used to estimate the annual ambient PM 10 concentration levels in the metropolis. Pulmonary functions of motorcycle taxi drivers and enclosed vehicle taxi drivers were measured and compared using the Mann-Whitney test. Multiple linear regression analysis was applied to estimate the effects of PM 10 exposure on the lung function of motorcycle taxi drivers. A total of 1283 motorcycle taxi drivers and 600 taxi drivers were investigated. The mean forced expiratory volume in 1 sec/forced vital capacity (FEV 1 /FVC) of the motorcycle taxi drivers was significantly lower than that of the taxi drivers (P < 0.001). The mean FEV 1 /FVC of motorcycle taxi drivers exposed to ≥50 µg/m 3 PM 10 was statistically lower (-2.82%; 95% confidence interval [CI]: -4.54% to -1.09%) and the mean % vital capacity (%VC) of those exposed to 40-49.9 µg/m 3 PM 10 was statistically lower than that of motorcycle taxi drivers exposed to <30 µg/m 3 PM 10 (-3.33%; 95% CI: -5.79% to -0.87%). Motorcycle taxi drivers were directly exposed to air pollution in their working environment. As a result, their lung function might decrease more than that of enclosed vehicle taxi drivers. With the possible exposure to ≥50 µg/m 3 PM 10 , the vehicular emission standards should be vigorously enforced. Further investigation is warranted to clarify the effect of lung dysfunction on the work and lifestyle of motorcycle taxi

Aspergillus prevalence in air conditioning filters from vehicles: taxis for patient transportation, forklifts, and personal vehicles.

PubMed

Viegas, Carla; Moreira, Ricardo; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Viegas, Susana

2018-05-04

The frequency and importance of Aspergillus infections is increasing worldwide. This study aimed to assess the occupational exposure of forklifts and taxi drivers to Aspergillus spp. Nineteen filters from air conditioning system of taxis, 17 from forklifts and 37 from personal vehicles were assessed. Filters extract were streaked onto MEA, DG18 and in azole-supplemented media. Real-time quantitative PCR amplification of selected Aspergillus species-complex was also performed. Forklifts filter samples presented higher median values. Aspergillus section Nigri was the most observed in forklifts filters in MEA (28.2%) and in azole-supplemented media. DNA from Aspergillus sections Fumigati and Versicolores was successfully amplified by qPCR. This study enlightens the added value of using filters from the air conditioning system to assess Aspergillus spp. occupational exposure. Aspergillus azole resistance screening should be included in future occupational exposure assessments.

Exposure to particles and nitrogen dioxide among taxi, bus and lorry drivers.

PubMed

Lewné, Marie; Nise, Gun; Lind, Marie-Louise; Gustavsson, Per

2006-03-01

The aims of this study have been to investigate the occurrence of systematic differences in the personal exposure to motor exhaust between different groups of taxi, bus and lorry drivers, and to study if these are influenced by the choice of exposure indicator. We used one indicator of the gaseous phase, nitrogen dioxide (NO(2)), and one of the particle phase (measured by DataRAM), of the exhausts. A total of 121 drivers were included in the study: 39 taxi drivers, 42 bus drivers and 40 lorry drivers. Personal measurements were performed during one working day. Nitrogen dioxide was measured with passive diffusive samplers and particles with Data-RAM, a logging instrument using nephelometric monitoring. The instrument measures particles between 0.1 and 10 microm in size. The average exposure to NO(2) for lorry drivers was 68 microg/m(3); for bus drivers 60 microg/m(3) and for taxi drivers 48 microg/m(3). For particles the exposure was 57 microg/m(3) for lorry drivers, 44 microg/m(3) for bus drivers and 26 microg/m(3) for taxi drivers. The result remained unchanged when exposures were adjusted for variation in urban background levels of NO(2) and particulate matter with an aerodynamic diameter <10 microm (PM(10)). Lorry drivers experienced the highest exposure and taxi drivers the lowest with bus drivers in an intermediate position, regardless of whether NO(2) or particles were used as exposure indicator. The levels of both NO(2) and particles were higher for bus drivers in the city than for them driving in the suburbs. Using diesel or petrol as a fuel for taxis had no influence on the exposure for the drivers, indicating that the taxi drivers' exposure mainly depends on exhaust from surrounding traffic.

Driving fatigue in professional drivers: a survey of truck and taxi drivers.

PubMed

Meng, Fanxing; Li, Shuling; Cao, Lingzhi; Li, Musen; Peng, Qijia; Wang, Chunhui; Zhang, Wei

2015-01-01

Fatigue among truck drivers has been studied extensively; however, less is known regarding the fatigue experience of taxi drivers in heavily populated metropolitan areas. This study aimed to compare the differences and similarities between truck and taxi driver fatigue to provide implications for the fatigue management and education of professional drivers. A sample of 274 truck drivers and 286 taxi drivers in Beijing was surveyed via a questionnaire, which included items regarding work characteristics, fatigue experience, accident information, attitude toward fatigue, and methods of counteracting fatigue. Driver fatigue was prevalent among professional drivers, and it was even more serious for taxi drivers. Taxi drivers reported more frequent fatigue experiences and were involved in more accidents. Among the contributing factors to fatigue, prolonged driving time was the most important factor identified by both driver groups. Importantly, the reason for the engagement in prolonged driving was neither due to the lack of awareness concerning the serious outcome of fatigue driving nor because of their poor detection of fatigue. The most probable reason was the optimism bias, as a result of which these professional drivers thought that fatigue was more serious for other drivers than for themselves, and they thought that they were effective in counteracting the effect of fatigue on their driving performance. Moreover, truck drivers tended to employ methods that require stopping to counteract fatigue, whereas taxi drivers preferred methods that were simultaneous with driving. Although both driver groups considered taking a nap as one of the most effective means to address fatigue, this method was not commonly used. Interestingly, these drivers were aware that the methods they frequently used were not the most effective means to counteract fatigue. This study provides knowledge on truck and taxi drivers' characteristics in fatigue experience, fatigue attitude, and

Hybrid Taxis Give Fuel Economy a Lift, Clean Cities, Fleet Experiences, April 2009 (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-04-01

Clean Cities helped Boston, San Antonio, and Cambridge create hybrid taxi programs. The hybrid taxis are able to achieve about twice the gas mileage of a conventional taxi while helping cut gasoline use and fuel costs. Tax credits and other incentives are helping both company owners and drivers make the switch to hybrids. Program leaders have learned some important lessons other cities can benefit from including learning a city's taxi structure, relaying benefits to drivers, and understanding the needs of owners.

Macro-level vulnerable road users crash analysis: A Bayesian joint modeling approach of frequency and proportion.

PubMed

Cai, Qing; Abdel-Aty, Mohamed; Lee, Jaeyoung

2017-10-01

This study aims at contributing to the literature on pedestrian and bicyclist safety by building on the conventional count regression models to explore exogenous factors affecting pedestrian and bicyclist crashes at the macroscopic level. In the traditional count models, effects of exogenous factors on non-motorist crashes were investigated directly. However, the vulnerable road users' crashes are collisions between vehicles and non-motorists. Thus, the exogenous factors can affect the non-motorist crashes through the non-motorists and vehicle drivers. To accommodate for the potentially different impact of exogenous factors we convert the non-motorist crash counts as the product of total crash counts and proportion of non-motorist crashes and formulate a joint model of the negative binomial (NB) model and the logit model to deal with the two parts, respectively. The formulated joint model is estimated using non-motorist crash data based on the Traffic Analysis Districts (TADs) in Florida. Meanwhile, the traditional NB model is also estimated and compared with the joint model. The result indicates that the joint model provides better data fit and can identify more significant variables. Subsequently, a novel joint screening method is suggested based on the proposed model to identify hot zones for non-motorist crashes. The hot zones of non-motorist crashes are identified and divided into three types: hot zones with more dangerous driving environment only, hot zones with more hazardous walking and cycling conditions only, and hot zones with both. It is expected that the joint model and screening method can help decision makers, transportation officials, and community planners to make more efficient treatments to proactively improve pedestrian and bicyclist safety. Published by Elsevier Ltd.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

DISPAQ: Distributed Profitable-Area Query from Big Taxi Trip Data †

PubMed Central

Putri, Fadhilah Kurnia; Song, Giltae; Rao, Praveen

2017-01-01

One of the crucial problems for taxi drivers is to efficiently locate passengers in order to increase profits. The rapid advancement and ubiquitous penetration of Internet of Things (IoT) technology into transportation industries enables us to provide taxi drivers with locations that have more potential passengers (more profitable areas) by analyzing and querying taxi trip data. In this paper, we propose a query processing system, called Distributed Profitable-Area Query (DISPAQ) which efficiently identifies profitable areas by exploiting the Apache Software Foundation’s Spark framework and a MongoDB database. DISPAQ first maintains a profitable-area query index (PQ-index) by extracting area summaries and route summaries from raw taxi trip data. It then identifies candidate profitable areas by searching the PQ-index during query processing. Then, it exploits a Z-Skyline algorithm, which is an extension of skyline processing with a Z-order space filling curve, to quickly refine the candidate profitable areas. To improve the performance of distributed query processing, we also propose local Z-Skyline optimization, which reduces the number of dominant tests by distributing killer profitable areas to each cluster node. Through extensive evaluation with real datasets, we demonstrate that our DISPAQ system provides a scalable and efficient solution for processing profitable-area queries from huge amounts of big taxi trip data. PMID:28946679

Taxi Time Prediction at Charlotte Airport Using Fast-Time Simulation and Machine Learning Techniques

NASA Technical Reports Server (NTRS)

Lee, Hanbong

2016-01-01

Accurate taxi time prediction is required for enabling efficient runway scheduling that can increase runway throughput and reduce taxi times and fuel consumptions on the airport surface. Currently NASA and American Airlines are jointly developing a decision-support tool called Spot and Runway Departure Advisor (SARDA) that assists airport ramp controllers to make gate pushback decisions and improve the overall efficiency of airport surface traffic. In this presentation, we propose to use Linear Optimized Sequencing (LINOS), a discrete-event fast-time simulation tool, to predict taxi times and provide the estimates to the runway scheduler in real-time airport operations. To assess its prediction accuracy, we also introduce a data-driven analytical method using machine learning techniques. These two taxi time prediction methods are evaluated with actual taxi time data obtained from the SARDA human-in-the-loop (HITL) simulation for Charlotte Douglas International Airport (CLT) using various performance measurement metrics. Based on the taxi time prediction results, we also discuss how the prediction accuracy can be affected by the operational complexity at this airport and how we can improve the fast time simulation model before implementing it with an airport scheduling algorithm in a real-time environment.

Predicting crash frequency for multi-vehicle collision types using multivariate Poisson-lognormal spatial model: A comparative analysis.

PubMed

Hosseinpour, Mehdi; Sahebi, Sina; Zamzuri, Zamira Hasanah; Yahaya, Ahmad Shukri; Ismail, Noriszura

2018-06-01

According to crash configuration and pre-crash conditions, traffic crashes are classified into different collision types. Based on the literature, multi-vehicle crashes, such as head-on, rear-end, and angle crashes, are more frequent than single-vehicle crashes, and most often result in serious consequences. From a methodological point of view, the majority of prior studies focused on multivehicle collisions have employed univariate count models to estimate crash counts separately by collision type. However, univariate models fail to account for correlations which may exist between different collision types. Among others, multivariate Poisson lognormal (MVPLN) model with spatial correlation is a promising multivariate specification because it not only allows for unobserved heterogeneity (extra-Poisson variation) and dependencies between collision types, but also spatial correlation between adjacent sites. However, the MVPLN spatial model has rarely been applied in previous research for simultaneously modelling crash counts by collision type. Therefore, this study aims at utilizing a MVPLN spatial model to estimate crash counts for four different multi-vehicle collision types, including head-on, rear-end, angle, and sideswipe collisions. To investigate the performance of the MVPLN spatial model, a two-stage model and a univariate Poisson lognormal model (UNPLN) spatial model were also developed in this study. Detailed information on roadway characteristics, traffic volume, and crash history were collected on 407 homogeneous segments from Malaysian federal roads. The results indicate that the MVPLN spatial model outperforms the other comparing models in terms of goodness-of-fit measures. The results also show that the inclusion of spatial heterogeneity in the multivariate model significantly improves the model fit, as indicated by the Deviance Information Criterion (DIC). The correlation between crash types is high and positive, implying that the occurrence of a

Nonconstant Positive Steady States and Pattern Formation of 1D Prey-Taxis Systems

NASA Astrophysics Data System (ADS)

Wang, Qi; Song, Yang; Shao, Lingjie

2017-02-01

Prey-taxis is the process that predators move preferentially toward patches with highest density of prey. It is well known to have an important role in biological control and the maintenance of biodiversity. To model the coexistence and spatial distributions of predator and prey species, this paper concerns nonconstant positive steady states of a wide class of prey-taxis systems with general functional responses over 1D domain. Linearized stability of the positive equilibrium is analyzed to show that prey-taxis destabilizes prey-predator homogeneity when prey repulsion (e.g., due to volume-filling effect in predator species or group defense in prey species) is present, and prey-taxis stabilizes the homogeneity otherwise. Then, we investigate the existence and stability of nonconstant positive steady states to the system through rigorous bifurcation analysis. Moreover, we provide detailed and thorough calculations to determine properties such as pitchfork and turning direction of the local branches. Our stability results also provide a stable wave mode selection mechanism for thee reaction-advection-diffusion systems including prey-taxis models considered in this paper. Finally, we provide numerical studies of prey-taxis systems with Holling-Tanner kinetics to illustrate and support our theoretical findings. Our numerical simulations demonstrate that the 2× 2 prey-taxis system is able to model the formation and evolution of various striking patterns, such as spikes, periodic oscillations, and coarsening even when the domain is one-dimensional. These dynamics can model the coexistence and spatial distributions of interacting prey and predator species. We also give some insights on how system parameters influence pattern formation in these models.

Driving to Better Health: Cancer and Cardiovascular Risk Assessment among Taxi Cab Operators in Chicago

PubMed Central

Apantaku-Onayemi, Funmi; Baldyga, William; Amuwo, Shaffdeen; Adefuye, Adedeji; Mason, Terry; Mitchell, Robin; Blumenthal, Daniel S.

2014-01-01

While a number of investigations of the health of taxi cab drivers have been conducted in Europe, Asia, and Africa, virtually none have been conducted in the United States. We undertook a survey of taxi cab operators in the Chicago area to understand better their health status and health promotion practices. The survey was completed by a convenience sample of 751 Chicago taxi drivers. Taxi drivers had low rates of insurance coverage, fruit and vegetable consumption, and physical activity compared with the general Chicago population. Participation in cancer screening tests was also lower for this group. A high proportion of taxi drivers are immigrants. They tend to be highly educated and report a readiness to engage in more health-promoting behaviors. Further research is needed to develop a targeted intervention for this population. PMID:22643623

Reductions in injury crashes associated with red light camera enforcement in oxnard, california.

PubMed

Retting, Richard A; Kyrychenko, Sergey Y

2002-11-01

This study estimated the impact of red light camera enforcement on motor vehicle crashes in one of the first US communities to employ such cameras-Oxnard, California. Crash data were analyzed for Oxnard and for 3 comparison cities. Changes in crash frequencies were compared for Oxnard and control cities and for signalized and nonsignalized intersections by means of a generalized linear regression model. Overall, crashes at signalized intersections throughout Oxnard were reduced by 7% and injury crashes were reduced by 29%. Right-angle crashes, those most associated with red light violations, were reduced by 32%; right-angle crashes involving injuries were reduced by 68%. Because red light cameras can be a permanent component of the transportation infrastructure, crash reductions attributed to camera enforcement should be sustainable.

Taxi Scrip Program in Seattle, Washington

DOT National Transportation Integrated Search

1982-09-01

The Municipality of Metropolitan Seattle (Metro) took over a taxi user-side subsidy program from the City of Seattle in December 1978, which was based on the sale of discounted taxicab scrip. Metro expanded the program, raised the discount, and condu...

Occupational health risks and intervention strategies for US taxi drivers.

PubMed

Murray, Kate E; Buul, Abdimalik; Aden, Rasheed; Cavanaugh, Alyson M; Kidane, Luwam; Hussein, Mikaiil; Eastman, Amelia; Checkoway, Harvey

2017-12-02

Research has shown that taxi drivers are at risk for numerous health concerns, such as low back and leg pain, linked to their highly sedentary occupation, long work hours and stressors related to the job (e.g. low income, safety threats). The goal of this study was to explore occupational health risks and opportunities for health interventions with taxi drivers using community-based participatory research (CBPR) methods. A mixed methods approach included first a convenience sample of 19 East African taxi drivers participating in focus group discussions. Second, a convenience sample of 75 current taxi drivers (M age = 45.7 years) and 25 non-driver comparison participants (M age = 40.3 years) were recruited to complete a structured self-reported questionnaire and objective measures of health. Health education was provided alongside the research to address common health concerns and to ensure mutual benefit and an action orientation. The focus groups described numerous health concerns that drivers attributed to their occupation, including chronic pain, sleep deprivation, cardiovascular disease, diabetes, kidney disease and eye problems, as the most common. Participants offered ideas for health interventions that include workplace reform and driver education. Quantitative data indicate that 44% of drivers reported their health as 'fair' or 'poor'. Drivers were more likely to report musculoskeletal pain, less sleep, more fatigue and less physical activity as compared to non-drivers. The majority of drivers reported financial and job dissatisfaction. The research provides data to inform targeted health interventions that support the health and safety of taxi drivers. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of BMI on the risk and frequency of AIS 3+ injuries in motor-vehicle crashes.

PubMed

Rupp, Jonathan D; Flannagan, Carol A C; Leslie, Andrew J; Hoff, Carrie N; Reed, Matthew P; Cunningham, Rebecca M

2013-01-01

Determine the effects of BMI on the risk of serious-to-fatal injury (Abbreviated Injury Scale ≥ 3 or AIS 3+) to different body regions for adults in frontal, nearside, farside, and rollover crashes. Multivariate logistic regression analysis was applied to a probability sample of adult occupants involved in crashes generated by combining the National Automotive Sampling System (NASS-CDS) with a pseudoweighted version of the Crash Injury Research and Engineering Network database. Logistic regression models were applied to weighted data to estimate the change in the number of occupants with AIS 3+ injuries if no occupants were obese. Increasing BMI increased risk of lower-extremity injury in frontal crashes, decreased risk of lower-extremity injury in nearside impacts, increased risk of upper-extremity injury in frontal and nearside crashes, and increased risk of spine injury in frontal crashes. Several of these findings were affected by interactions with gender and vehicle type. If no occupants in frontal crashes were obese, 7% fewer occupants would sustain AIS 3+ upper-extremity injuries, 8% fewer occupants would sustain AIS 3+ lower-extremity injuries, and 28% fewer occupants would sustain AIS 3+ spine injuries. Results of this study have implications on the design and evaluation of vehicle safety systems. Copyright © 2013 The Obesity Society.

Spatial analysis of macro-level bicycle crashes using the class of conditional autoregressive models.

PubMed

Saha, Dibakar; Alluri, Priyanka; Gan, Albert; Wu, Wanyang

2018-02-21

The objective of this study was to investigate the relationship between bicycle crash frequency and their contributing factors at the census block group level in Florida, USA. Crashes aggregated over the census block groups tend to be clustered (i.e., spatially dependent) rather than randomly distributed. To account for the effect of spatial dependence across the census block groups, the class of conditional autoregressive (CAR) models were employed within the hierarchical Bayesian framework. Based on four years (2011-2014) of crash data, total and fatal-and-severe injury bicycle crash frequencies were modeled as a function of a large number of variables representing demographic and socio-economic characteristics, roadway infrastructure and traffic characteristics, and bicycle activity characteristics. This study explored and compared the performance of two CAR models, namely the Besag's model and the Leroux's model, in crash prediction. The Besag's models, which differ from the Leroux's models by the structure of how spatial autocorrelation are specified in the models, were found to fit the data better. A 95% Bayesian credible interval was selected to identify the variables that had credible impact on bicycle crashes. A total of 21 variables were found to be credible in the total crash model, while 18 variables were found to be credible in the fatal-and-severe injury crash model. Population, daily vehicle miles traveled, age cohorts, household automobile ownership, density of urban roads by functional class, bicycle trip miles, and bicycle trip intensity had positive effects in both the total and fatal-and-severe crash models. Educational attainment variables, truck percentage, and density of rural roads by functional class were found to be negatively associated with both total and fatal-and-severe bicycle crash frequencies. Published by Elsevier Ltd.

[Occupational risk factors and perceptions of air pollution by motorcycle taxi drivers in Cotonou, Benin].

PubMed

Lawin, Hervé; Ayi Fanou, Lucie; Hinson, Vikkey; Tollo, Brice; Fayomi, Benjamin; Ouendo, Edgard-Marius

Motorcycle taxis occupy a major place in urban transport. Motorcycle taxi drivers are exposed to occupational risk factors (ORF) including air pollution. The objective of this study was to evaluate these ORF among motorcycle taxi drivers and their perceptions of air pollution. This mixed study was conducted on motorcycle taxi drivers in Cotonou. The qualitative study was based on focus groups concerning 16 items from the Participatory Occupational Risk Screening Guide (DEPARIS) until saturation and after triangulation of data. The quantitative study consisted of administering a questionnaire addressing socioeconomic and demographic characteristics, cardiopulmonary diseases, and perception of air -pollution risk factors among 397 Cotonou motorcycle taxi drivers. Drivers perceived poor road conditions, effort and handling, and lack of social security as unsatisfactory ORF. Their mean age was 40.95 ± 8.75 years and 45.84% had primary -education. They had been working as motorcycle taxi drivers for an average of 134.95 ± 101.53 months with an average income of FCFA 3138 ± 1238. These occupational factors were significantly associated with cardiopulmonary disorders, observed in 63.2% of drivers. Less than 1/3 of drivers felt that air pollution affected their personal health. Motorcycle taxi drivers have a poor perception of ORF and the severity of exposure to air pollution in this occupation. There is a need to take action to promote the health of this population.

Analyzing road design risk factors for run-off-road crashes in The Netherlands with crash prediction models.

PubMed

van Petegem, J W H Jan Hendrik; Wegman, Fred

2014-06-01

About 50% of all road traffic fatalities and 30% of all traffic injuries in the Netherlands take place on rural roads with a speed limit of 80 km/h. About 50% of these crashes are run-off-road (ROR) crashes. To reduce the number of crashes on this road type, attention should be put on improving the safety of the infrastructure of this road type. With the development of a crash prediction model for ROR crashes on rural roads with a speed limit of 80 km/h, this study aims at making a start in providing the necessary new tools for a proactive road safety policy to road administrators in the Netherlands. The paper presents a basic framework of the model development, comprising a problem description, the data used, and the method for developing the model. The model is developed with the utilization of generalized linear modeling in SAS, using the Negative Binomial probability distribution. A stepwise approach is used by adding one variable at a time, which forms the basis for striving for a parsimonious model and the evaluation of the model. The likelihood ratio test and the Akaike information criterion are used to assess the model fit, and parameter estimations are compared with literature findings to check for consistency. The results comprise two important outcomes. One is a crash prediction model (CPM) to estimate the relative safety of rural roads with a speed limit of 80 km/h in a network. The other is a small set of estimated effects of traffic volume and road characteristics on ROR crash frequencies. The results may lead to adjustments of the road design guidelines in the Netherlands and to further research on the quantification of risk factors with crash prediction models. Copyright © 2014 Elsevier Ltd. All rights reserved.

National Ridesharing Demonstration Program : `Maxi-Taxi' Services in the Tidewater Region of Virginia

DOT National Transportation Integrated Search

1985-07-01

In November 1980, the Tidewater Regional Transit Authority (TRT) Implemented a series of shared-ride taxi services under the program name "Maxi-Taxi" (name which was subsequently changed to Maxi-Ride to avert legal challenges). These services, suppli...

Revisiting crash spatial heterogeneity: A Bayesian spatially varying coefficients approach.

PubMed

Xu, Pengpeng; Huang, Helai; Dong, Ni; Wong, S C

2017-01-01

This study was performed to investigate the spatially varying relationships between crash frequency and related risk factors. A Bayesian spatially varying coefficients model was elaborately introduced as a methodological alternative to simultaneously account for the unstructured and spatially structured heterogeneity of the regression coefficients in predicting crash frequencies. The proposed method was appealing in that the parameters were modeled via a conditional autoregressive prior distribution, which involved a single set of random effects and a spatial correlation parameter with extreme values corresponding to pure unstructured or pure spatially correlated random effects. A case study using a three-year crash dataset from the Hillsborough County, Florida, was conducted to illustrate the proposed model. Empirical analysis confirmed the presence of both unstructured and spatially correlated variations in the effects of contributory factors on severe crash occurrences. The findings also suggested that ignoring spatially structured heterogeneity may result in biased parameter estimates and incorrect inferences, while assuming the regression coefficients to be spatially clustered only is probably subject to the issue of over-smoothness. Copyright © 2016 Elsevier Ltd. All rights reserved.

Motorcycle crashes potentially preventable by three crash avoidance technologies on passenger vehicles.

PubMed

Teoh, Eric R

2018-07-04

The objective of this study was to identify and quantify the motorcycle crash population that would be potential beneficiaries of 3 crash avoidance technologies recently available on passenger vehicles. Two-vehicle crashes between a motorcycle and a passenger vehicle that occurred in the United States during 2011-2015 were classified by type, with consideration of the functionality of 3 classes of passenger vehicle crash avoidance technologies: frontal crash prevention, lane maintenance, and blind spot detection. Results were expressed as the percentage of crashes potentially preventable by each type of technology, based on all known types of 2-vehicle crashes and based on all crashes involving motorcycles. Frontal crash prevention had the largest potential to prevent 2-vehicle motorcycle crashes with passenger vehicles. The 3 technologies in sum had the potential to prevent 10% of fatal 2-vehicle crashes and 23% of police-reported crashes. However, because 2-vehicle crashes with a passenger vehicle represent fewer than half of all motorcycle crashes, these technologies represent a potential to avoid 4% of all fatal motorcycle crashes and 10% of all police-reported motorcycle crashes. Refining the ability of passenger vehicle crash avoidance systems to detect motorcycles represents an opportunity to improve motorcycle safety. Expanding the capabilities of these technologies represents an even greater opportunity. However, even fully realizing these opportunities can affect only a minority of motorcycle crashes and does not change the need for other motorcycle safety countermeasures such as helmets, universal helmet laws, and antilock braking systems.

Identification of high pedestrian crash locations.

DOT National Transportation Integrated Search

2018-03-01

An initial step in reducing the frequency of pedestrian crashes is identifying where they occur or where there is a concern they are likely to occur. As part of a Federal Highway Administration project, the Guidebook on Identification of High Pedestr...

Respiratory symptoms and lung function in garage workers and taxi drivers.

PubMed

Bener, A; Galadari, I; al-Mutawa, J K; al-Maskari, F; Das, M; Abuzeid, M S

1998-12-01

The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p < 0.007); dyspneoa (p < 0.001); and sinusitis (p < 0.03). A higher prevalence of all acute symptoms was recorded in garage workers than in taxi drivers, although the differences were significant only for throat (p < 0.02), hearing problems (p < 0.002); nose (dryness, bleeding and secretion) (p < 0.008); and low back pain (p < 0.05). Almost all forced spirometric tests in the exposed garage workers were lower than in taxi drivers. The results of stepwise multiple regression analysis showed that only phlegm, sinusitis, hearing problems, nasal catarrh, throat, low back pain, smoking and FEF25-75, variables were statistically significant predictors as risk factors. In conclusion, the present study suggests that a high prevalence of respiratory symptoms is associated with exposure to motor vehicle exhaust emission in garage working places. Long-term working as garage workers in the United Arab Emirates (UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.

"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. Copyright © 2015

Shared-Ride Taxi Service in Boston, MA

DOT National Transportation Integrated Search

1985-03-01

This report presents an evaluation of the Boston Shared-Ride Taxi Demonstration. The City of Boston's Traffic and Parking Department, the project grantee, designed a shared-ride service for Boston's Allston-Brighton neighborhood; Boston Cab Associati...

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

PubMed

Viegas, Carla; Monteiro, Ana; Dos Santos, Mateus; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal Gomes, Anita; Marchand, Geneviève; Lacombe, Nancy; Viegas, Susana

2018-07-01

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m 2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Math on the Job. Taxi Driver.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

This booklet is intended to help mainstreamed mentally retarded, emotionally disturbed, or learning disabled high school students acquire a basic understanding of the responsibilities and working conditions of taxi drivers and to practice basic math skills necessary in the occupation. The first section provides a brief introduction to the…

76 FR 33639 - Safety Zone; New York Water Taxi 10th Anniversary Fireworks

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-09

...-AA00 Safety Zone; New York Water Taxi 10th Anniversary Fireworks, Upper New York Bay, Red Hook, NY... New York Water Taxi. The fireworks will commence at 9 p.m. on June 21, 2011 and will last... CFR Part 165 Harbors, Marine safety, Navigation (water), Reporting and recordkeeping requirements...

Crash-resistant fuel system effectiveness in civil helicopter crashes.

PubMed

Hayden, Mark S; Shanahan, Dennis F; Chen, Li-Hui; Baker, Susan P

2005-08-01

Crash-resistant fuel systems (CRFS) have demonstrated close to 100% effectiveness in survivable crashes of Army helicopters, but the technology has been slow to transfer into the civil helicopter arena. Federal standards for civil helicopter CRFS are less stringent than those for military helicopters. A reduction in standards for CRFS in military helicopters is being considered. The goal of this study was to determine whether crashes of civil helicopters with CRFS are less likely to result in post-crash fire than crashes of those without. Crashes of civil helicopters during 1982-2004 were analyzed, comparing Bell 206 helicopters manufactured with CRFS with Aerospatial 350 helicopters manufactured during the same period (post-1981), but lacking CRFS. Bell 206 helicopters with CRFS were also compared with earlier models without CRFS. The highest proportion of crashes with post-crash fires (11.3%) was in AS-350s manufactured after 1981 (non-CRFS), and the lowest (3.7%) was in Bell 206s (with CRFS) [unadjusted risk ratio (RR) = 3.3, 95% confidence interval (CI) = 1.04, 10.50; adjusted for light and weather, RR = 2.81, Cl = 0.82, 9.69]. Earlier models of Bell 206s without CRFS had higher risk of post-crash fire than post-1981 models with CRFS (7.4% vs. 3.7%; adjusted RR = 2.11, Cl = 0.82, 5.45). The results of this study suggest a better performance, in terms of post-crash fire prevention, of CRFS-equipped civil helicopters as compared with those without CRFS. It is possible that CRFS in civil helicopters have not achieved the same degree of effectiveness as CRFS in military helicopters. CRFS should be used more widely in civil helicopters. The more stringent CRFS requirements for military helicopters should not be reduced without further research.

A preliminary investigation of the relationships between historical crash and naturalistic driving.

PubMed

Pande, Anurag; Chand, Sai; Saxena, Neeraj; Dixit, Vinayak; Loy, James; Wolshon, Brian; Kent, Joshua D

2017-04-01

This paper describes a project that was undertaken using naturalistic driving data collected via Global Positioning System (GPS) devices to demonstrate a proof-of-concept for proactive safety assessments of crash-prone locations. The main hypothesis for the study is that the segments where drivers have to apply hard braking (higher jerks) more frequently might be the "unsafe" segments with more crashes over a long-term. The linear referencing methodology in ArcMap was used to link the GPS data with roadway characteristic data of US Highway 101 northbound (NB) and southbound (SB) in San Luis Obispo, California. The process used to merge GPS data with quarter-mile freeway segments for traditional crash frequency analysis is also discussed in the paper. A negative binomial regression analyses showed that proportion of high magnitude jerks while decelerating on freeway segments (from the driving data) was significantly related with the long-term crash frequency of those segments. A random parameter negative binomial model with uniformly distributed parameter for ADT and a fixed parameter for jerk provided a statistically significant estimate for quarter-mile segments. The results also indicated that roadway curvature and the presence of auxiliary lane are not significantly related with crash frequency for the highway segments under consideration. The results from this exploration are promising since the data used to derive the explanatory variable(s) can be collected using most off-the-shelf GPS devices, including many smartphones. Copyright © 2017 Elsevier Ltd. All rights reserved.

Changes in functional connectivity dynamics associated with vigilance network in taxi drivers.

PubMed

Shen, Hui; Li, Zhenfeng; Qin, Jian; Liu, Qiang; Wang, Lubin; Zeng, Ling-Li; Li, Hong; Hu, Dewen

2016-01-01

An increasing number of neuroimaging studies have suggested that the fluctuations of low-frequency resting-state functional connectivity (FC) are not noise but are instead linked to the shift between distinct cognitive states. However, there is very limited knowledge about whether and how the fluctuations of FC at rest are influenced by long-term training and experience. Here, we investigated how the dynamics of resting-state FC are linked to driving behavior by comparing 20 licensed taxi drivers with 20 healthy non-drivers using a sliding window approach. We found that the driving experience could be effectively decoded with 90% (p<0.001) accuracy by the amplitude of low-frequency fluctuations in some specific connections, based on a multivariate pattern analysis technique. Interestingly, the majority of these connections fell within a set of distributed regions named "the vigilance network". Moreover, the decreased amplitude of the FC fluctuations within the vigilance network in the drivers was negatively correlated with the number of years that they had driven a taxi. Furthermore, temporally quasi-stable functional connectivity segmentation revealed significant differences between the drivers and non-drivers in the dwell time of specific vigilance-related transient brain states, although the brain's repertoire of functional states was preserved. Overall, these results suggested a significant link between the changes in the time-dependent aspects of resting-state FC within the vigilance network and long-term driving experiences. The results not only improve our understanding of how the brain supports driving behavior but also shed new light on the relationship between the dynamics of functional brain networks and individual behaviors. Copyright © 2015 Elsevier Inc. All rights reserved.

GEOGRAPIC INFORMATION SYSTEMS IN DETERMINING ROAD TRAFFIC CRASH ANALYSIS IN IBADAN, NIGERIA.

PubMed

Rukewe, A; Taiwo, O J; Fatiregun, A A; Afuwape, O O; Alonge, T O

2014-01-01

Road traffic accidents are frequent in this environment, hence the need to determine the place of geographic information systems in the documentation of road traffic accidents. To investigate and document the variations in crash frequencies by types and across different road types in Ibadan, Nigeria. Road traffic accident data between January and June 2011 were obtained from the University College Hospital Emergency Department's trauma registry. All the traffic accidents were categorized into motor vehicular, motorbike and pedestrian crashes. Georeferencing of accident locations mentioned by patients was done using a combination of Google Earth and ArcGIS software. Nearest neighbor statistic, Moran's-I, Getis-Ord statistics, Student T-test, and ANOVA were used in investigating the spatial dynamics in crashes. Out of 600 locations recorded, 492 (82.0%) locations were correctly georeferenced. Crashes were clustered in space with motorbike crashes showing greatest clustering. There was significant difference in crashes between dual and non-dual carriage roads (P = 0.0001), but none between the inner city and the periphery (p = 0.115). However, significant variations also exist among the three categories analyzed (p = 0.004) and across the eleven Local Government Areas (P = 0.017). This study showed that the use of Geographic Information System can help in understanding variations in road traffic accident occurrence, while at the same time identifying locations and neighborhoods with unusually higher accidents frequency.

On-road emission characteristics of CNG-fueled bi-fuel taxis

NASA Astrophysics Data System (ADS)

Yao, Zhiliang; Cao, Xinyue; Shen, Xianbao; Zhang, Yingzhi; Wang, Xintong; He, Kebin

2014-09-01

To alleviate air pollution and lessen the petroleum demand from the motor vehicle sector in China, natural gas vehicles (NGVs) have been rapidly developed over the last several years. However, the understanding of the real-world emissions of NGVs is very limited. In this study, the emissions from 20 compressed-natural-gas-fueled bi-fuel taxis were measured using a portable emission measurement system (PEMS) under actual driving conditions in Yichang, China. The emission characteristics of the tested vehicles were analyzed, revealing that the average CO2, CO, HC and NOx emissions from the tested compressed-natural-gas (CNG) taxis under urban driving conditions were 1.6, 4.0, 2.0 and 0.98 times those under highway road conditions, respectively. The CO, HC and NOx emissions from Euro 3 CNG vehicles were approximately 40%, 55% and 44% lower than those from Euro 2 vehicles, respectively. Compared with the values for light-duty gasoline vehicles reported in the literature, the CO2 and CO emissions from the tested CNG taxis were clearly lower; however, significant increases in the HC and NOx emissions were observed. Finally, we normalized the emissions under the actual driving cycles of the entire test route to the New European Driving Cycle (NEDC)-based emissions using a VSP modes method developed by North Carolina State University. The simulated NEDC-based CO emissions from the tested CNG taxis were better than the corresponding emissions standards, whereas the simulated NEDC-based HC and NOx emissions greatly exceeded the standards. Thus, more attention should be paid to the emissions from CNG vehicles. As for the CNG-fueled bi-fuel taxis currently in use, the department of environmental protection should strengthen their inspection and supervision to reduce the emissions from these vehicles. The results of this study will be helpful in understanding and controlling emissions from CNG-fueled bi-fuel vehicles in China.

14 CFR Appendix C to Part 330 - Forms for Air Taxi Operators

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Forms for Air Taxi Operators C Appendix C to Part 330 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... Part 330—Forms for Air Taxi Operators ER20AU02.009 ER20AU02.010 ER20AU02.011 ER20AU02.012 ER20AU02.013...

Association of heart rate variability in taxi drivers with marked changes in particulate air pollution in Beijing in 2008.

PubMed

Wu, Shaowei; Deng, Furong; Niu, Jie; Huang, Qinsheng; Liu, Youcheng; Guo, Xinbiao

2010-01-01

Heart rate variability (HRV), a marker of cardiac autonomic function, has been -associated with particulate matter (PM) air pollution, especially in older patients and those with cardio-vascular diseases. However, the effect of PM exposure on cardiac autonomic function in young, healthy adults has received less attention. We evaluated the relationship between exposure to traffic-related PM with an aerodynamic diameter taxi drivers. Continuous measurements of personal exposure to PM2.5 and ambulatory electrocardiogram monitoring were conducted on 11 young healthy taxi drivers for a 12-hr work shift during their work time (09002100 hr) before, during, and after the Beijing 2008 Olympic Games. Mixed-effects regression models were used to estimate associations between PM2.5 exposure and percent changes in 5-min HRV indices after combining data from the three time periods and controlling for potentially confounding variables. Personal exposures of taxi drivers to PM2.5 changed markedly across the three time -periods. The standard deviation of normal-to-normal (SDNN) intervals decreased by 2.2% [95% confidence interval (CI), 3.8% to 0.6%] with an interquartile range (IQR; 69.5 microg/m3) increase in the 30-min PM2.5 moving average, whereas the low-frequency and high-frequency powers decreased by 4.2% (95% CI, 9.0% to 0.8%) and 6.2% (95% CI, 10.7% to 1.5%), respectively, in association with an IQR increase in the 2-hr PM2.5 moving average. Marked changes in traffic-related PM2.5 exposure were associated with altered cardiac autonomic function in young healthy adults.

Perseus Taxi

NASA Technical Reports Server (NTRS)

1991-01-01

The Perseus proof-of-concept vehicle is seen here as it taxis on Rogers Dry Lake, adjacent the Dryden Flight Research Center, Edwards, California. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST project. The

Difference between car-to-cyclist crash and near crash in a perpendicular crash configuration based on driving recorder analysis.

PubMed

Ito, Daisuke; Hayakawa, Kosei; Kondo, Yuma; Mizuno, Koji; Thomson, Robert; Piccinini, Giulio Bianchi; Hosokawa, Naruyuki

2018-08-01

Analyzing a crash using driving recorder data makes it possible to objectively examine factors contributing to the occurrence of the crash. In this study, car-to-cyclist crashes and near crashes recorded on cars equipped with advanced driving recorders were compared with each other in order to examine the factors that differentiate near crashes from crashes, as well as identify the causes of the crashes. Focusing on cases where the car and cyclist approached each other perpendicularly, the differences in the car's and cyclist's parameters such as velocity, distance and avoidance behavior were analyzed. The results show that car-to-cyclist crashes would not be avoidable when the car approaching the cyclist enters an area where the average deceleration required to stop the car is more than 0.45 G (4.4 m/s 2 ). In order for this situation to occur, there are two types of cyclist crash scenarios. In the first scenario, the delay in the drivers' reaction in activating the brakes is the main factor responsible for the crash. In this scenario, time-to-collision when the cyclist first appears in the video is more than 2.0 s. In the second scenario, the sudden appearance of a cyclist from behind an obstacle on the street is the factor responsible for the crash. In this case, the time-to-collision is less than 1.2 s, and the crash cannot be avoided even if the driver exhibited avoidance maneuvers. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choiron, Moch Agus, E-mail: agus-choiron@ub.ac.id; Sudjito,; Hidayati, Nafisah Arina

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.more » 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.« less

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.

Sleep-related crash characteristics: Implications for applying a fatigue definition to crash reports.

PubMed

Filtness, A J; Armstrong, K A; Watson, A; Smith, S S

2017-02-01

Sleep-related (SR) crashes are an endemic problem the world over. However, police officers report difficulties in identifying sleepiness as a crash contributing factor. One approach to improving the sensitivity of SR crash identification is by applying a proxy definition post hoc to crash reports. To identify the prominent characteristics of SR crashes and highlight the influence of proxy definitions, ten years of Queensland (Australia) police reports of crashes occurring in ≥100km/h speed zones were analysed. In Queensland, two approaches are routinely taken to identifying SR crashes. First, attending police officers identify crash causal factors; one possible option is 'fatigue/fell asleep'. Second, a proxy definition is applied to all crash reports. Those meeting the definition are considered SR and added to the police-reported SR crashes. Of the 65,204 vehicle operators involved in crashes 3449 were police-reported as SR. Analyses of these data found that male drivers aged 16-24 years within the first two years of unsupervised driving were most likely to have a SR crash. Collision with a stationary object was more likely in SR than in not-SR crashes. Using the proxy definition 9739 (14.9%) crashes were classified as SR. Using the proxy definition removes the findings that SR crashes are more likely to involve males and be of high severity. Additionally, proxy defined SR crashes are no less likely at intersections than not-SR crashes. When interpreting crash data it is important to understand the implications of SR identification because strategies aimed at reducing the road toll are informed by such data. Without the correct interpretation, funding could be misdirected. Improving sleepiness identification should be a priority in terms of both improvement to police and proxy reporting. Copyright © 2015 Elsevier Ltd. All rights reserved.

Monopoly Profits: The Market for Taxi Licenses.

ERIC Educational Resources Information Center

Keane, Michael

1981-01-01

Presents a case study dealing with open versus closed markets for use in college economics classes. Using the example of the taxi license monopoly in Dublin, Ireland, students examine how theories of supply and demand explain the characteristics of open and closed markets. (AM)

A semi-nonparametric Poisson regression model for analyzing motor vehicle crash data.

PubMed

Ye, Xin; Wang, Ke; Zou, Yajie; Lord, Dominique

2018-01-01

This paper develops a semi-nonparametric Poisson regression model to analyze motor vehicle crash frequency data collected from rural multilane highway segments in California, US. Motor vehicle crash frequency on rural highway is a topic of interest in the area of transportation safety due to higher driving speeds and the resultant severity level. Unlike the traditional Negative Binomial (NB) model, the semi-nonparametric Poisson regression model can accommodate an unobserved heterogeneity following a highly flexible semi-nonparametric (SNP) distribution. Simulation experiments are conducted to demonstrate that the SNP distribution can well mimic a large family of distributions, including normal distributions, log-gamma distributions, bimodal and trimodal distributions. Empirical estimation results show that such flexibility offered by the SNP distribution can greatly improve model precision and the overall goodness-of-fit. The semi-nonparametric distribution can provide a better understanding of crash data structure through its ability to capture potential multimodality in the distribution of unobserved heterogeneity. When estimated coefficients in empirical models are compared, SNP and NB models are found to have a substantially different coefficient for the dummy variable indicating the lane width. The SNP model with better statistical performance suggests that the NB model overestimates the effect of lane width on crash frequency reduction by 83.1%.

[Association between psychosocial aspects of work and quality of life among motorcycle taxi drivers].

PubMed

Teixeira, Jules Ramon Brito; Boery, Eduardo Nagib; Casotti, Cezar Augusto; Araújo, Tânia Maria de; Pereira, Rafael; Ribeiro, Ícaro José Santos; Rios, Marcela Andrade; Amorim, Camila Rego; Moreira, Ramon Missias; Boery, Rita Narriman Silva de Oliveira; Sales, Zenilda Nogueira

2015-01-01

This study aimed to evaluate the quality of life of motorcycle taxi drivers and the association with psychosocial characteristics of their work. This was a cross-sectional epidemiological study with a sample of 400 motorcycle taxi drivers in Jequié, Bahia State, Brazil. The study used a form containing demographic and socioeconomic data, WHO Quality of Life-Bref Questionnaire (WHOQOL-Bref), and the Job Content Questionnaire (JCQ). Motorcycle taxi drivers with greater decision-making control over their work showed better self-rated quality of life in the psychological domain; those with high psychological demands presented better self-rated quality of life in the social relations and environmental domains; those with high strain and active work showed better self-rated quality of life in the social and environmental domains. The psychosocial work environment and especially decision-making autonomy were thus important determinants of self-rated quality of life in this group of motorcycle taxi drivers.

Impact of urban built environment on urban short-distance taxi travel: the case of Shanghai

NASA Astrophysics Data System (ADS)

Wu, Zhuoye; Zhuo, Jian

2018-05-01

The excessive individual motorized transport is the main cause of urban congestion and generates negative consequences on urban environmental quality, energy consumption, infrastructure supply and urban security. Bicycle can compete effectively with automobile for short-distance travels within 3km. If we take action to encourage the rider to shift from automobile to bike for the short-distance travels, it leaves us a great chance to reduce the modal share of individual motorized mode. This paper focus on the spatial impact of built environment on short-distance taxi riders’ travel behaviour. The data sources include taxi trajectory data for a week, demographic data of the Sixth National Census, POI data. In this paper, we figure out the volumes and spatial distribution of short-distance taxi travel in the central city of Shanghai. We build a multiple regression model to quantitative analyze the impact of urban built environment on urban short-distance taxi travel. The findings explain the spatial distribution short-distance taxi travel. In the conclusion, some advice are provided on how planners change the spatial settings to discourage short-distance individual motorized travel.

Modeling the effects of AADT on predicting multiple-vehicle crashes at urban and suburban signalized intersections.

PubMed

Chen, Chen; Xie, Yuanchang

2016-06-01

Annual Average Daily Traffic (AADT) is often considered as a main covariate for predicting crash frequencies at urban and suburban intersections. A linear functional form is typically assumed for the Safety Performance Function (SPF) to describe the relationship between the natural logarithm of expected crash frequency and covariates derived from AADTs. Such a linearity assumption has been questioned by many researchers. This study applies Generalized Additive Models (GAMs) and Piecewise Linear Negative Binomial (PLNB) regression models to fit intersection crash data. Various covariates derived from minor-and major-approach AADTs are considered. Three different dependent variables are modeled, which are total multiple-vehicle crashes, rear-end crashes, and angle crashes. The modeling results suggest that a nonlinear functional form may be more appropriate. Also, the results show that it is important to take into consideration the joint safety effects of multiple covariates. Additionally, it is found that the ratio of minor to major-approach AADT has a varying impact on intersection safety and deserves further investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of methodologies for analysis of the dungeness B accidental aircraft crash risk.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 additionalmore » 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.« less

Modeling left-turn crash occurrence at signalized intersections by conflicting patterns.

PubMed

Wang, Xuesong; Abdel-Aty, Mohamed

2008-01-01

In order to better understand the underlying crash mechanisms, left-turn crashes occurring at 197 four-legged signalized intersections over 6 years were classified into nine patterns based on vehicle maneuvers and then were assigned to intersection approaches. Crash frequency of each pattern was modeled at the approach level by mainly using Generalized Estimating Equations (GEE) with the Negative Binomial as the link function to account for the correlation among the crash data. GEE with a binomial logit link function was also applied for patterns with fewer crashes. The Cumulative Residuals test shows that, for correlated left-turn crashes, GEE models usually outperformed basic Negative Binomial models. The estimation results show that there are obvious differences in the factors that cause the occurrence of different left-turn collision patterns. For example, for each pattern, the traffic flows to which the colliding vehicles belong are identified to be significant. The width of the crossing distance (represented by the number of through lanes on the opposing approach of the left-turning traffic) is associated with more left-turn traffic colliding with opposing through traffic (Pattern 5), but with less left-turning traffic colliding with near-side crossing through traffic (Pattern 8). The safety effectiveness of the left-turning signal is not consistent for different crash patterns; "protected" phasing is correlated with fewer Pattern 5 crashes, but with more Pattern 8 crashes. The study indicates that in order to develop efficient countermeasures for left-turn crashes and improve safety at signalized intersections, left-turn crashes should be considered in different patterns.

Terminal area automatic navigation, guidance, and control 1: Automatic rollout, turnoff, and taxis

NASA Technical Reports Server (NTRS)

Pines, S.

1981-01-01

A study developed for the TCV B-737, designed to apply existing navigation aids plus magnetic leader cable signals and develop breaking and reverse thrust guidance laws to provide for rapid automated rollout, turnoff, and taxi to reduce runway occupation time for a wide variety of landing conditions for conventional commercial-type aircraft, is described. Closed loop guidance laws for braking and reverse thrust are derived for rollout, turnoff, and taxi, as functions of the landing speed, the desired taxi speed and the distance to go. Brake limitations for wet runway conditions and reverse thrust limitations are taken into account to provide decision rules to avoid tire skid and to choose an alternate turnoff point, farther down the runway, to accommodate extreme landing conditions.

Shared Ride Taxi Feeder Service in Memphis, TN

DOT National Transportation Integrated Search

1988-03-01

From May 1983 through October 1984, the Memphis Area Transit Authority (MATA) conducted the Taxi Feeder Demonstration Project. It entailed the operation of fixed-route feeder services through three low-density neighborhoods and one industrial park, c...

Data development technical support document for the aircraft crash risk analysis methodology (ACRAM) standard

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, C.Y.; Glaser, R.E.; Mensing, R.W.

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 thatmore » 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.« less

Exploring the effects of state highway safety laws and sociocultural characteristics on fatal crashes.

PubMed

Dong, Chunjiao; Nambisan, Shashi S; Clarke, David B; Sun, Jian

2017-04-03

Distinguished from the traditional perspectives in crash analyses, which examined the effects of geometric design features, traffic factors, and other relevant attributes on the crash frequencies of roadway entities, our study focuses on exploring the effects of highway safety laws, as well as sociocultural characteristics, on fatal crashes across states. Law and regulation related data were collected from the Insurance Institute for Highway Safety, State Highway Safety Offices, and Governors Highway Safety Association. A variety of sociodemographic characteristics were obtained from the U.S. Census Bureau. In addition, cultural factors and other attributes from a variety of resources are considered and incorporated in the modeling process. These data and fatal crash counts were collected for the 50 U.S. states and the District of Columbia and were analyzed using zero-truncated negative binomial (ZTNB) regression models. The results show that, in law and regulation-related factors, the use of speed cameras, no handheld cell phone ban, limited handheld cell phone ban, and no text messaging ban are found to have significant effects on fatal crashes. Regarding sociocultural characteristics, married couples with both husband and wife in the labor force are found to be associated with lower crash frequencies, the ratios of workers traveling to work by carpool, those driving alone, workers working outside the county of residence, language other than English and limited English fluency, and the number of licensed drivers are found to be associated with higher crash frequencies. Through reviewing and modeling existing state highway safety laws and sociocultural characteristics, the results reveal new insights that could influence policy making. In addition, the results would benefit amending existing laws and regulations and provide testimony about highway safety issues before lawmakers consider new legislation.

Prevalence of teen driver errors leading to serious motor vehicle crashes.

PubMed

Curry, Allison E; Hafetz, Jessica; Kallan, Michael J; Winston, Flaura K; Durbin, Dennis R

2011-07-01

Motor vehicle crashes are the leading cause of adolescent deaths. Programs and policies should target the most common and modifiable reasons for crashes. We estimated the frequency of critical reasons for crashes involving teen drivers, and examined in more depth specific teen driver errors. The National Highway Traffic Safety Administration's (NHTSA) National Motor Vehicle Crash Causation Survey collected data at the scene of a nationally representative sample of 5470 serious crashes between 7/05 and 12/07. NHTSA researchers assigned a single driver, vehicle, or environmental factor as the critical reason for the event immediately leading to each crash. We analyzed crashes involving 15-18 year old drivers. 822 teen drivers were involved in 795 serious crashes, representing 335,667 teens in 325,291 crashes. Driver error was by far the most common reason for crashes (95.6%), as opposed to vehicle or environmental factors. Among crashes with a driver error, a teen made the error 79.3% of the time (75.8% of all teen-involved crashes). Recognition errors (e.g., inadequate surveillance, distraction) accounted for 46.3% of all teen errors, followed by decision errors (e.g., following too closely, too fast for conditions) (40.1%) and performance errors (e.g., loss of control) (8.0%). Inadequate surveillance, driving too fast for conditions, and distracted driving together accounted for almost half of all crashes. Aggressive driving behavior, drowsy driving, and physical impairments were less commonly cited as critical reasons. Males and females had similar proportions of broadly classified errors, although females were specifically more likely to make inadequate surveillance errors. Our findings support prioritization of interventions targeting driver distraction and surveillance and hazard awareness training. Copyright © 2010 Elsevier Ltd. All rights reserved.

Association of Heart Rate Variability in Taxi Drivers with Marked Changes in Particulate Air Pollution in Beijing in 2008

PubMed Central

Wu, Shaowei; Deng, Furong; Niu, Jie; Huang, Qinsheng; Liu, Youcheng; Guo, Xinbiao

2010-01-01

Background Heart rate variability (HRV), a marker of cardiac autonomic function, has been associated with particulate matter (PM) air pollution, especially in older patients and those with cardiovascular diseases. However, the effect of PM exposure on cardiac autonomic function in young, healthy adults has received less attention. Objectives We evaluated the relationship between exposure to traffic-related PM with an aerodynamic diameter ≤ 2.5 μm (PM2.5) and HRV in a highly exposed panel of taxi drivers. Methods Continuous measurements of personal exposure to PM2.5 and ambulatory electrocardiogram monitoring were conducted on 11 young healthy taxi drivers for a 12-hr work shift during their work time (0900–2100 hr) before, during, and after the Beijing 2008 Olympic Games. Mixed-effects regression models were used to estimate associations between PM2.5 exposure and percent changes in 5-min HRV indices after combining data from the three time periods and controlling for potentially confounding variables. Results Personal exposures of taxi drivers to PM2.5 changed markedly across the three time periods. The standard deviation of normal-to-normal (SDNN) intervals decreased by 2.2% [95% confidence interval (CI), −3.8% to −0.6%] with an interquartile range (IQR; 69.5 μg/m3) increase in the 30-min PM2.5 moving average, whereas the low-frequency and high-frequency powers decreased by 4.2% (95% CI, −9.0% to 0.8%) and 6.2% (95% CI, −10.7% to −1.5%), respectively, in association with an IQR increase in the 2-hr PM2.5 moving average. Conclusions Marked changes in traffic-related PM2.5 exposure were associated with altered cardiac autonomic function in young healthy adults. PMID:20056565

Shared-Ride Taxi Computer Control System Requirements Study

DOT National Transportation Integrated Search

1977-08-01

The technical problem of scheduling and routing shared-ride taxi service is so great that only computers can handle it efficiently. This study is concerned with defining the requirements of such a computer system. The major objective of this study is...

Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

PubMed

Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

2013-12-01

Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

Indiana crash facts 1997

DOT National Transportation Integrated Search

1997-01-01

Indiana Crash Facts 1997...is the fifth annual publication : of Indiana Crash Facts. This year significant changes have been made : to the book, including the consolidation of the Alcohol Crash Facts and : the Crash Facts book into one publication. A...

Indiana crash facts 1996

DOT National Transportation Integrated Search

1996-01-01

According to Indiana State Police Crash Reports, : 221,465 traffic crashes were reported in Indiana : during 1996 (Table 1). Of these, 870 were fatal : crashes in which 982 people died. There were an : additional 52,058 personal injury crashes and a ...

Analysis of crash proportion by vehicle type at traffic analysis zone level: A mixed fractional split multinomial logit modeling approach with spatial effects.

PubMed

Lee, Jaeyoung; Yasmin, Shamsunnahar; Eluru, Naveen; Abdel-Aty, Mohamed; Cai, Qing

2018-02-01

In traffic safety literature, crash frequency variables are analyzed using univariate count models or multivariate count models. In this study, we propose an alternative approach to modeling multiple crash frequency dependent variables. Instead of modeling the frequency of crashes we propose to analyze the proportion of crashes by vehicle type. A flexible mixed multinomial logit fractional split model is employed for analyzing the proportions of crashes by vehicle type at the macro-level. In this model, the proportion allocated to an alternative is probabilistically determined based on the alternative propensity as well as the propensity of all other alternatives. Thus, exogenous variables directly affect all alternatives. The approach is well suited to accommodate for large number of alternatives without a sizable increase in computational burden. The model was estimated using crash data at Traffic Analysis Zone (TAZ) level from Florida. The modeling results clearly illustrate the applicability of the proposed framework for crash proportion analysis. Further, the Excess Predicted Proportion (EPP)-a screening performance measure analogous to Highway Safety Manual (HSM), Excess Predicted Average Crash Frequency is proposed for hot zone identification. Using EPP, a statewide screening exercise by the various vehicle types considered in our analysis was undertaken. The screening results revealed that the spatial pattern of hot zones is substantially different across the various vehicle types considered. Copyright © 2017 Elsevier Ltd. All rights reserved.

14 CFR 330.29 - What information must air taxi operators submit on Form 330 (Final) and Form 330-C?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false What information must air taxi operators... COMPENSATION OF AIR CARRIERS Application Procedures § 330.29 What information must air taxi operators submit on Form 330 (Final) and Form 330-C? As an air taxi operator, you must complete Form 330 (Final) in...

14 CFR 330.29 - What information must air taxi operators submit on Form 330 (Final) and Form 330-C?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false What information must air taxi operators... COMPENSATION OF AIR CARRIERS Application Procedures § 330.29 What information must air taxi operators submit on Form 330 (Final) and Form 330-C? As an air taxi operator, you must complete Form 330 (Final) in...

Talent in the taxi: a model system for exploring expertise

PubMed Central

Woollett, Katherine; Spiers, Hugo J.; Maguire, Eleanor A.

2009-01-01

While there is widespread interest in and admiration of individuals with exceptional talents, surprisingly little is known about the cognitive and neural mechanisms underpinning talent, and indeed how talent relates to expertise. Because many talents are first identified and nurtured in childhood, it can be difficult to determine whether talent is innate, can be acquired through extensive practice or can only be acquired in the presence of the developing brain. We sought to address some of these issues by studying healthy adults who acquired expertise in adulthood. We focused on the domain of memory and used licensed London taxi drivers as a model system. Taxi drivers have to learn the layout of 25 000 streets in London and the locations of thousands of places of interest, and pass stringent examinations in order to obtain an operating licence. Using neuropsychological assessment and structural and functional magnetic resonance imaging, we addressed a range of key questions: in the context of a fully developed brain and an average IQ, can people acquire expertise to an exceptional level; what are the neural signatures, both structural and functional, associated with the use of expertise; does expertise change the brain compared with unskilled control participants; does it confer any cognitive advantages, and similarly, does it come at a cost to other functions? By studying retired taxi drivers, we also consider what happens to their brains and behaviour when experts stop using their skill. Finally, we discuss how the expertise of taxi drivers might relate to the issue of talent and innate abilities. We suggest that exploring talent and expertise in this manner could have implications for education, rehabilitation of patients with cognitive impairments, understanding individual differences and possibly conditions such as autism where exceptional abilities can be a feature. PMID:19528024

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

Conscientious personality and young drivers' crash risk.

PubMed

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

2015-09-01

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. 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 18months 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. 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). 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, and suffered fewer CNC. 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 drivers' personality into account when providing guidance, and establishing norms and

Aeroassisted manned transfer vehicle (TAXI) for advanced Mars Transportation: NASA/USRA 1987 Senior Design Project

NASA Technical Reports Server (NTRS)

1987-01-01

A conceptual design study of an aeroassisted orbital transfer vehicle is discussed. Nicknamed TAXI, it will ferry personnel and cargo: (1) between low Earth orbit and a spacecraft circling around the Sun in permanent orbit intersecting gravitational fields of Earth and Mars, and (2) between the cycling spacecraft and a Mars orbiting station, co-orbiting with Phobos. Crew safety and mission flexibility (in terms of ability to provide a wide range of delta-V) were given high priority. Three versions were considered, using the same overall configuration based on a low L/D aerobrake with the geometry of a raked off elliptical cone with ellipsoidal nose and a toroidal skirt. The propulsion system consists of three gimballed LOX/LH2 engines firing away from the aerobrake. The versions differ mainly in the size of the aeroshields and propellant tanks. TAXI A version resulted from an initial effort to design a single transfer vehicle able to meet all delta-V requirements during the 15-year period (2025 to 2040) of Mars mission operations. TAXI B is designed to function with the cycling spacecraft moving in a simplified, nominal trajectory. On Mars missions, TAXI B would be able to meet the requirements of all the missions with a relative approach velocity near Mars of less than 9.3 km/sec. Finally, TAXI C is a revision of TAXI A, a transfer vehicle designed for missions with a relative velocity near Mars larger than 9.3 km/sec. All versions carry a crew of 9 (11 with modifications) and a cargo of 10000 lbm. Trip duration varies from 1 day for transfer from LEO to the cycling ship to nearly 5 days for transfer from the ship to the Phobos orbit.

Modeling crash injury severity by road feature to improve safety.

PubMed

Penmetsa, Praveena; Pulugurtha, Srinivas S

2018-01-02

The objective of this research is 2-fold: to (a) model and identify critical road features (or locations) based on crash injury severity and compare it with crash frequency and (b) model and identify drivers who are more likely to contribute to crashes by road feature. Crash data from 2011 to 2013 were obtained from the Highway Safety Information System (HSIS) for the state of North Carolina. Twenty-three different road features were considered, analyzed, and compared with each other as well as no road feature. A multinomial logit (MNL) model was developed and odds ratios were estimated to investigate the effect of road features on crash injury severity. Among the many road features, underpass, end or beginning of a divided highway, and on-ramp terminal on crossroad are the top 3 critical road features. Intersection crashes are frequent but are not highly likely to result in severe injuries compared to critical road features. Roundabouts are least likely to result in both severe and moderate injuries. Female drivers are more likely to be involved in crashes at intersections (4-way and T) compared to male drivers. Adult drivers are more likely to be involved in crashes at underpasses. Older drivers are 1.6 times more likely to be involved in a crash at the end or beginning of a divided highway. The findings from this research help to identify critical road features that need to be given priority. As an example, additional advanced warning signs and providing enlarged or highly retroreflective signs that grab the attention of older drivers may help in making locations such as end or beginning of a divided highway much safer. Educating drivers about the necessary skill sets required at critical road features in addition to engineering solutions may further help them adopt safe driving behaviors on the road.

The effect of crash experience on changes in risk taking among urban and rural young people.

PubMed

Lin, Mau-Roung; Huang, Wenzheng; Hwang, Hei-Fen; Wu, Hong-Dar Isaac; Yen, Lee-Lan

2004-03-01

A 20-month prospective study was conducted to investigate the effect of motorcycle crash experience on changes in risk taking among 2514 urban and 2304 rural students in Taiwan. Risk taking was assessed using a 14-item self-administered questionnaire at the beginning and end of the study. A risk-taking score for each student at the initial and the last follow-up assessments was generated from adding up points across all 14 items. For exposure variables, the study documented past motorcycle crash history at the initial assessment and collected detailed information about any motorcycle crash involvement that occurred during the study period. A general linear mixed model was applied to assess the effects of prior and recent crash involvements on the path of risk-taking behavior. The results show that at the initial assessment, students with crash experience had higher risk-taking levels than those without crash experience. However, crash experience, irregardless of whether it was measured in terms of crash history prior to the study, crash frequency, time elapsed since the last crash, or crash severity, did not significantly change the risk-taking path among students, even though its effect differed between urban and rural areas.

Crash test ratings and real-world frontal crash outcomes: a CIREN study.

PubMed

Ryb, Gabriel E; Burch, Cynthia; Kerns, Timothy; Dischinger, Patricia C; Ho, Shiu

2010-05-01

To establish whether the Insurance Institute for Highway Safety (IIHS) offset crash test ratings are linked to different mortality rates in real world frontal crashes. The study used Crash Injury Research Engineering Network drivers of age older than 15 years who were involved in frontal crashes. The Crash Injury Research Engineering Network is a convenience sample of persons injured in crashes with at least one Abbreviated Injury Scale score of 3+ injury or two Abbreviated Injury Scale score of 2+ injuries who were either treated at a Level I trauma center or died. Cases were grouped by IIHS crash test ratings (i.e., good, acceptable, marginal, poor, and not rated). Those rated marginal were excluded because of their small numbers. Mortality rates experienced by these ratings-based groups were compared using the Mantel-Haenszel chi test. Multiple logistic regression models were built to adjust for confounders (i.e., occupant, vehicular, and crash factors). A total of 1,226 cases were distributed within not rated (59%), poor (12%), average (16%), and good (14%) categories. Those rated good and average experienced a lower unadjusted mortality rate. After adjustment by confounders, those in vehicles rated good experienced a lower risk of death (adjusted OR 0.38 [0.16-0.90]) than those in vehicles rated poor. There was no significant effect for "acceptable" rating. Other factors influencing the occurrence of death were age, DeltaV >or=70 km/h, high body mass index, and lack of restraint use. After adjusting for occupant, vehicular, and crash factors, drivers of vehicles rated good by the IIHS experienced a lower risk of death in frontal crashes.

Spinal injury in car crashes: crash factors and the effects of occupant age.

PubMed

Bilston, Lynne E; Clarke, Elizabeth C; Brown, Julie

2011-08-01

Motor vehicle crashes are the leading cause of serious spinal injury in most developed nations. However, since these injuries are rare, systematic analyses of the crash factors that are predictive of spinal injury have rarely been performed. This study aimed to use a population-reference crash sample to identify crash factors associated with moderate to severe spinal injury, and how these vary with occupant age. The US National Automotive Sampling System Crashworthiness Data System (NASS) data for 1993-2007 were analysed using logistic regression to identify crash factors associated with Abbreviated Injury Scale (AIS)2+ spinal injury among restrained vehicle passengers. Risk of moderate or severe spinal injury (AIS2+) was associated with higher severity crashes (OR=3.5 (95% CI 2.6 to 4.6)), intrusion into an occupant's seating position (OR=2.7 (95% CI 1.9 to 3.7)), striking a fixed object rather than another car (OR=1.7 (95% CI 1.3 to 2.1)), and use of a shoulder-only belt (OR=2.7 (95% CI 1.5 to 4.8)). Older occupants (65 years or older) were at higher risk of spinal injury than younger adults in frontal, side and rollover crashes. Children under 16 were at a lower risk of spinal injury than adults in all crash types except frontal crashes. While the risk of serious spinal injury in motor vehicle crashes is low, these injuries are more common in crashes of higher severity or into fixed objects, and in the presence of intrusion. There are elevated risks of spinal injury for older occupants compared with younger adults, which may reflect changes in biomechanical tolerances with age. Children appear to be at lower risk of serious spinal injury than adults except in frontal crashes.

Taxi Regulatory Revision in Portland Oregon : Background and Implementation

DOT National Transportation Integrated Search

1980-09-01

The Portland Council has adopted successive waves of taxi regulatory revisions. Effective in Marh, 1979, the previous ceiling on total permits was removed and entry was opened to qualified applicats. The new reulations also provided for flat, discoun...

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Health Status, Intention to Seek Health Examination, and Participation in Health Education Among Taxi Drivers in Jinan, China

PubMed Central

Yang, Yan; Fan, Xiao-sheng; Tian, Cui-huan; Zhang, Wei; Li, Jie; Li, Shu-qing

2014-01-01

Background: Taxi drivers are exposed to various risk factors such as work overload, stress, an irregular diet, and a sedentary lifestyle, which make these individuals vulnerable to many diseases. This study was designed to assess the health status of this occupational group. Objectives: The objective was to explore the health status, the intention to seek health examination, and participation in health education among taxi drivers in Jinan, China. Patients and Methods: The sample-size was determined scientifically. The systematic sampling procedure was used for selecting the sample. Four hundred taxi drivers were randomly selected from several taxi companies in Jinan. In total, 396 valid questionnaires (from 370 males and 26 females) were returned. Health status, intention to seek health examination, and participation in health education were assessed by a self-designed questionnaire. Other personal information including sex, age, ethnicity, marital status, years of employment as a taxi driver, education level, and habits were also collected. Results: This survey revealed that 54.8% of taxi drivers reported illness in the last two weeks and 44.7% of participants reported chronic diseases. The prevalence rates of hypertension, diabetes mellitus, gastroenteritis, arthritis, and heart disease were 18.2%, 8.8%, 26%, 18.4%, and 4.8% of questioned taxi drivers, respectively. Significant self-reported symptoms included fatigue, waist and back pain, headache, dyspepsia, and dry throat affecting 49.7%, 26.2%, 23.5%, 26%, and 27% of participants, respectively. In total, 90.1% of subjects thought that it was necessary to receive a regular health examination. Only 17.9% of subjects had been given information about health education, and significantly, more than 87% of subjects who had been given information about health education reported that the information had been helpful. Conclusions: Taxi drivers’ health was poor in our survey. Thus, using health education interventions

Traffic crash statistics report, 1998

DOT National Transportation Integrated Search

1999-01-01

The information contained in this Traffic Crash Facts booklet is extracted from law : enforcement agency long-form reports of traffic crashes. A law enforcement officer must submit a : long-form crash report when investigating: : Motor vehicle crashe...

Traffic crash statistics report, 1995

DOT National Transportation Integrated Search

1996-01-01

The information contained in this Traffic Crash Facts booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashe...

Traffic crash statistics report, 1996

DOT National Transportation Integrated Search

1997-11-01

The information contained in this Traffic Crash Facts booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashe...

Traffic crash statistics report, 1994

DOT National Transportation Integrated Search

1995-01-01

The information contained in this Traffic Crash Data booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashes...

Traffic crash statistics report, 2004

DOT National Transportation Integrated Search

2005-01-01

The information contained in this Traffic Crash Data booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashes...

Traffic crash statistics report, 1997

DOT National Transportation Integrated Search

1998-01-01

The information contained in this Traffic Crash Facts booklet is extracted from law enforcement agency : long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report when : investigating: : Motor vehicle crashe...

Evaluating the need for surface treatments to reduce crash frequency on horizontal curves.

DOT National Transportation Integrated Search

2013-10-01

The application of high-friction surface treatments at appropriate horizontal curve locations throughout the : state has the potential to improve driver performance and reduce the number of crashes experienced at : horizontal curves. These treatments...

Effect of Surface Traffic Count on Taxi Time at Dallas-Fort Worth (DFW) International Airport

NASA Technical Reports Server (NTRS)

Kistler, Matthew Stephen; Gupta, Gautam

2008-01-01

As the amount of air traffic increases over the years, most airports simply do not have the means of expanding to handle the intensified traffic on the surface that will ensue. Precise surveillance equipment and automation concepts, as well as advanced surface traffic algorithms are being developed to improve airport efficiency. These surface algorithms require inputs unique to each airport to ensure maximum efficiency, and minimal taxi delay. This study analyzes surface traffic at Dallas-Fort Worth International Airport (DFW) to determine the effect of the number of aircraft on the surface and the amount of stop and go situations they experience to the amount of additional taxi time encountered. If the surface capacity of an airport is known, minimal delay can be accomplished by limiting the number of taxiing aircraft to that capacity. This concept is related to highways, where traffic flow drastically decreases as more cars occupy the road. An attempt to minimize this effect on highways is seen with the use of metering lights at freeway on-ramps. Since the surface traffic at airports is highly regulated, and aircraft are less mobile on the ground, limiting the surface count to a certain number can greatly reduce the amount of additional taxi time encountered, as well as reduce hazardous emissions. This study will also find the regions of an airport that encounter the most additional taxi time when the number of aircraft in that area is increased. This could help surface traffic algorithms avoid congesting that area, or re-route aircraft to different runways when that area reaches its capacity. The relationship between the amount of stop and go situations an aircraft encounters and their effect on the taxi time of that aircraft will also be investigated. This will help to determine the effect of holding an aircraft on the taxiway as opposed to re-routing it. The lesser of the two should be used when developing surface traffic algorithms to further minimize the

Bayesian spatiotemporal crash frequency models with mixture components for space-time interactions.

PubMed

Cheng, Wen; Gill, Gurdiljot Singh; Zhang, Yongping; Cao, Zhong

2018-03-01

The traffic safety research has developed spatiotemporal models to explore the variations in the spatial pattern of crash risk over time. Many studies observed notable benefits associated with the inclusion of spatial and temporal correlation and their interactions. However, the safety literature lacks sufficient research for the comparison of different temporal treatments and their interaction with spatial component. This study developed four spatiotemporal models with varying complexity due to the different temporal treatments such as (I) linear time trend; (II) quadratic time trend; (III) Autoregressive-1 (AR-1); and (IV) time adjacency. Moreover, the study introduced a flexible two-component mixture for the space-time interaction which allows greater flexibility compared to the traditional linear space-time interaction. The mixture component allows the accommodation of global space-time interaction as well as the departures from the overall spatial and temporal risk patterns. This study performed a comprehensive assessment of mixture models based on the diverse criteria pertaining to goodness-of-fit, cross-validation and evaluation based on in-sample data for predictive accuracy of crash estimates. The assessment of model performance in terms of goodness-of-fit clearly established the superiority of the time-adjacency specification which was evidently more complex due to the addition of information borrowed from neighboring years, but this addition of parameters allowed significant advantage at posterior deviance which subsequently benefited overall fit to crash data. The Base models were also developed to study the comparison between the proposed mixture and traditional space-time components for each temporal model. The mixture models consistently outperformed the corresponding Base models due to the advantages of much lower deviance. For cross-validation comparison of predictive accuracy, linear time trend model was adjudged the best as it recorded the

Target crashes and safety benefits estimation methodology for pedestrian crash avoidance/mitigation systems

DOT National Transportation Integrated Search

2014-04-01

Through the analysis of national crash databases from the National Highway Traffic Safety Administration, pre-crash scenarios are identified, prioritized, and described for the development of objective tests for pedestrian crash avoidance/mitigation ...

Taxi trips distribution modeling based on Entropy-Maximizing theory: A case study in Harbin city-China

NASA Astrophysics Data System (ADS)

Tang, Jinjun; Zhang, Shen; Chen, Xinqiang; Liu, Fang; Zou, Yajie

2018-03-01

Understanding Origin-Destination distribution of taxi trips is very important for improving effects of transportation planning and enhancing quality of taxi services. This study proposes a new method based on Entropy-Maximizing theory to model OD distribution in Harbin city using large-scale taxi GPS trajectories. Firstly, a K-means clustering method is utilized to partition raw pick-up and drop-off location into different zones, and trips are assumed to start from and end at zone centers. A generalized cost function is further defined by considering travel distance, time and fee between each OD pair. GPS data collected from more than 1000 taxis at an interval of 30 s during one month are divided into two parts: data from first twenty days is treated as training dataset and last ten days is taken as testing dataset. The training dataset is used to calibrate model while testing dataset is used to validate model. Furthermore, three indicators, mean absolute error (MAE), root mean square error (RMSE) and mean percentage absolute error (MPAE), are applied to evaluate training and testing performance of Entropy-Maximizing model versus Gravity model. The results demonstrate Entropy-Maximizing model is superior to Gravity model. Findings of the study are used to validate the feasibility of OD distribution from taxi GPS data in urban system.

Idaho traffic crashes, 2007

DOT National Transportation Integrated Search

2007-01-01

Idaho Traffic Crashes 2007 provides an annual description of motor vehicle crash characteristics for : crashes that have occurred within the State of Idaho. This document is used by state and local : transportation, law enforcement, health, and other...

Spatial-temporal travel pattern mining using massive taxi trajectory data

NASA Astrophysics Data System (ADS)

Zheng, Linjiang; Xia, Dong; Zhao, Xin; Tan, Longyou; Li, Hang; Chen, Li; Liu, Weining

2018-07-01

Deep understanding of residents' travel patterns would provide helpful insights into the mechanisms of many socioeconomic phenomena. With the rapid development of location-aware computing technologies, researchers have easy access to large quantities of travel data. As an important data source, taxi trajectory data are featured by their high quality, good continuity and wide distribution, making it suitable for travel pattern mining. In this paper, we use taxi trajectory data to study spatial-temporal characterization of urban residents' travel patterns from two aspects: attractive areas and hot paths. Firstly, a framework of trajectory preprocessing, including data cleaning and extracting the taxi passenger pick-up/drop-off points, is presented to reduce the noise and redundancy in raw trajectory data. Then, a grid density based clustering algorithm is proposed to discover travel attractive areas in different periods of a day. On this basis, we put forward a spatial-temporal trajectory clustering method to discover hot paths among travel attractive areas. Compared with previous algorithms, which only consider the spatial constraint between trajectories, temporal constraint is also considered in our method. Through the experiments, we discuss how to determine the optimal parameters of the two clustering algorithms and verify the effectiveness of the algorithms using real data. Furthermore, we analyze spatial-temporal characterization of Chongqing residents' travel pattern.

Idaho traffic crashes, 2009

DOT National Transportation Integrated Search

2009-01-01

Idaho Traffic Crashes 2009 provides an annual description of motor vehicle crash characteristics for : crashes that have occurred on public roads within the State of Idaho. This document is used by state and : local transportation, law enforcement, h...

Idaho traffic crashes, 2008

DOT National Transportation Integrated Search

2008-01-01

Idaho Traffic Crashes 2008 provides an annual description of motor vehicle crash characteristics for : crashes that have occurred on public roads within the State of Idaho. This document is used by state and : local transportation, law enforcement, h...

Geo-spatial and log-linear analysis of pedestrian and bicyclist crashes involving school-aged children.

PubMed

Abdel-Aty, Mohamed; Chundi, Sai Srinivas; Lee, Chris

2007-01-01

There is a growing concern with the safety of school-aged children. This study identifies the locations of pedestrian/bicyclist crashes involving school-aged children and examines the conditions when these crashes are more likely to occur. The 5-year records of crashes in Orange County, Florida where school-aged children were involved were used. The spatial distribution of these crashes was investigated using the Geographic Information Systems (GIS) and the likelihoods of crash occurrence under different conditions were estimated using log-linear models. A majority of school-aged children crashes occurred in the areas near schools. Although elementary school children were generally very involved, middle and high school children were more involved in crashes, particularly on high-speed multi-lane roadways. Driver's age, gender, and alcohol use, pedestrian's/bicyclist's age, number of lanes, median type, speed limits, and speed ratio were also found to be correlated with the frequency of crashes. The result confirms that school-aged children are exposed to high crash risk near schools. High crash involvement of middle and high school children reflects that middle and high schools tend to be located near multi-lane high-speed roads. The pedestrian's/bicyclist's demographic factors and geometric characteristics of the roads adjacent to schools associated with school children's crash involvement are of interest to school districts.

Indianapolis Experience with Open Entry in the Taxi Industry

DOT National Transportation Integrated Search

1980-09-01

During the early 1970s the City of Indianapolis reversed a long-standing policy of closed entry into the taxi industry by redistributing many of the existing permits. This report is an account of the Indianapolis experience with open entry. It is bas...

Crash test rating and likelihood of major thoracoabdominal injury in motor vehicle crashes: the new car assessment program side-impact crash test, 1998-2010.

PubMed

Figler, Bradley D; Mack, Christopher D; Kaufman, Robert; Wessells, Hunter; Bulger, Eileen; Smith, Thomas G; Voelzke, Bryan

2014-03-01

The National Highway Traffic Safety Administration's New Car Assessment Program (NCAP) implemented side-impact crash testing on all new vehicles since 1998 to assess the likelihood of major thoracoabdominal injuries during a side-impact crash. Higher crash test rating is intended to indicate a safer car, but the real-world applicability of these ratings is unknown. Our objective was to determine the relationship between a vehicle's NCAP side-impact crash test rating and the risk of major thoracoabdominal injury among the vehicle's occupants in real-world side-impact motor vehicle crashes. The National Automotive Sampling System Crashworthiness Data System contains detailed crash and injury data in a sample of major crashes in the United States. For model years 1998 to 2010 and crash years 1999 to 2010, 68,124 occupants were identified in the Crashworthiness Data System database. Because 47% of cases were missing crash severity (ΔV), multiple imputation was used to estimate the missing values. The primary predictor of interest was the occupant vehicle's NCAP side-impact crash test rating, and the outcome of interest was the presence of major (Abbreviated Injury Scale [AIS] score ≥ 3) thoracoabdominal injury. In multivariate analysis, increasing NCAP crash test rating was associated with lower likelihood of major thoracoabdominal injury at high (odds ratio [OR], 0.8; 95% confidence interval [CI], 0.7-0.9; p < 0.01) and medium (OR, 0.9; 95% CI, 0.8-1.0; p < 0.05) crash severity (ΔV), but not at low ΔV (OR, 0.95; 95% CI, 0.8-1.2; p = 0.55). In our model, older age and absence of seat belt use were associated with greater likelihood of major thoracoabdominal injury at low and medium ΔV (p < 0.001), but not at high ΔV (p ≥ 0.09). Among adults in model year 1998 to 2010 vehicles involved in medium and high severity motor vehicle crashes, a higher NCAP side-impact crash test rating is associated with a lower likelihood of major thoracoabdominal trauma

Compliance and enforcement of a partial smoking ban in Lisbon taxis: an exploratory cross-sectional study.

PubMed

Ravara, Sofia B; Castelo-Branco, Miguel; Aguiar, Pedro; Calheiros, Jose M

2013-02-14

Research evaluating enforcement and compliance with smoking partial bans is rather scarce, especially in countries with relative weak tobacco control policies, such as Portugal. There is also scarce evidence on specific high risk groups such as vehicle workers. In January 2008, Portugal implemented a partial ban, followed by poor enforcement. The purpose of this study was to explore the effectiveness of a partial smoking ban in a pro-smoking environment, specifically transportation by taxi in the city of Lisbon. Ban effectiveness was generally defined by ban awareness and support, compliance and enforcement. Exploratory cross-sectional study; purposive sampling in selected Lisbon streets. Structured interviews were conducted by trained researchers while using taxi services (January 2009-December 2010). 250 taxi drivers (98.8% participation rate). Chi-square, McNemar, Man Whitney tests and multiple logistic regression were performed. Of the participants, 249 were male; median age was 53.0 years; 43.6% were current smokers. Most participants (82.8%) approved comprehensive bans; 84.8% reported that clients still asked to smoke in their taxis; 16.8% allowed clients to smoke. Prior to the ban this value was 76.9% (p < 0.001). The major reason for not allowing smoking was the legal ban and associated fines (71.2%). Of the smokers, 66.1% admitted smoking in their taxi. Stale smoke smells were detected in 37.6% of the cars. None of the taxi drivers did ever receive a fine for non-compliance. Heavy smoking, night-shift and allowing smoking prior the ban predicted non-compliance. Despite the strong ban support observed, high smoking prevalence and poor enforcement contribute to low compliance. The findings also suggest low compliance among night-shift and vehicle workers. This study clearly demonstrates that a partial and poorly-enforced ban is vulnerable to breaches, and highlights the need for clear and strong policies.

[A KABP (knowledge, attitude, belief and behavior) study about AIDS among taxi drivers and hotel attendants in Beijing].

PubMed

Zhang, X; Luo, B; Zhang, K

1994-12-01

This article reports the KABP study on 448 taxi drivers and 556 hotel attendants in Beijing for the first time in China. A self-administered questionnaire was used to investigate knowledge, attitude, belief and practice (KABP) about AIDS. In terms of knowledge, 23.8% of hotel attendants and 36.8% of taxi drivers did not know that contact with blood could transmit HIV. Thirtyfive percent of hotel attendants and 42.2% of taxi drivers did not believe that intravenous drug users were at high risk. Some drivers (13.6%) and hotel attendants (3.4%) reported having multiple sexual partners. Forty-one point nine percent of taxi drivers and 16.6% of hotel attendants preferred the idea of multiple sexual partners. Among hotel attendants, a negative association was found between knowledge about AIDS and multiple sexual behavior (P < 0.01). Regarding attitude toward condom use, 56.2% of taxi drivers and 47.8% of hotel attendants who have had a sexual experience thought that condom use interfered with sexual pleasure. Seventy-six point eight percent of taxi drivers and 79.8% of hotel attendants believed that they could change their behaviors in order to minimize the chances of getting HIV. This study indicates that HIV education is important in reducing the number of sexual partners and promoting the use of safe sex practices like condom use. Furthermore, as reported by the study population, education can change behavior.

Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers.

PubMed

Vieira, Marcelo C; Sperandei, Sandro; Reis, Arianne C

2016-05-01

The aim of this study was to assess the physical activity profile of taxi drivers and its relationship with hypertension prevalence in this group of workers. Cross sectional exploratory study. Between November 2008 and April 2009, 491 taxi drivers from Rio de Janeiro, Brazil, answered a questionnaire focusing on previous hypertension diagnosis, occupational characteristics and physical activity habits. Two logistic models were developed to determine risk factors related to hypertension and to find variables associated with a higher probability of sedentarism. Hypertension prevalence was 22.6%. The workload of the group investigated was high. Results indicate that 'age', 'Body Mass Index', 'physical activity', and 'years as a taxi driver' are related to the probability of hypertension. Physical activity was shown to be a protection factor for hypertension, even considering the deleterious effect of time as a taxi driver. Our results also determined that the practice of physical activity is influenced by age, level of education and workload. It is recommended that programs to combat sedentary lifestyles as well as measures to reduce workloads be developed as strategies to prevent hypertension.

Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers.

PubMed

Vieira, M C; Sperandei, S; Reis, A

2015-02-10

The aim of this study was to assess the physical activity profile of taxi drivers and its relationship with hypertension prevalence in this group of workers. Cross sectional exploratory study. Between November 2008 and April 2009, 491 taxi drivers from Rio de Janeiro, Brazil, answered a questionnaire focusing on previous hypertension diagnosis, occupational characteristics and physical activity habits. Two logistic models were developed to determine risk factors related to hypertension and to find variables associated with a higher probability of sedentarism. Hypertension prevalence was 22.6%. The workload of the group investigated was high. Results indicate that 'age', 'body mass index', 'physical activity', and 'years as a taxi driver' are related to the probability of hypertension. Physical activity was shown to be a protection factor for hypertension, even considering the deleterious effect of time as a taxi driver. Our results also determined that the practice of physical activity is influenced by age, level of education and workload. It is recommended that programs to combat sedentary lifestyles as well as measures to reduce workloads be developed as strategies to prevent hypertension.

Meta-analysis of the effect of road work zones on crash occurrence.

PubMed

Theofilatos, Athanasios; Ziakopoulos, Apostolos; Papadimitriou, Eleonora; Yannis, George; Diamandouros, Konstantinos

2017-11-01

There is strong evidence that work zones pose increased risk of crashes and injuries. The two most common risk factors associated with increased crash frequencies are work zone duration and length. However, relevant research on the topic is relatively limited. For that reason, this paper presents formal meta-analyses of studies that have estimated the relationship between the number of crashes and work zone duration and length, in order to provide overall estimates of those effects on crash frequencies. All studies presented in this paper are crash prediction models with similar specifications. According to the meta-analyses and after correcting for publication bias when it was considered appropriate, the summary estimates of regression coefficients were found to be 0.1703 for duration and 0.862 for length. These effects were significant for length but not for duration. However, the overall estimate of duration was significant before correcting for publication bias. Separate meta-analyses on the studies examining both duration and length was also carried out in order to have rough estimates of the combined effects. The estimate of duration was found to be 0.953, while for length was 0.847. Similar to previous meta-analyses the effect of duration after correcting for publication bias is not significant, while the effect of length was significant at a 95% level. Meta-regression findings indicate that the main factors influencing the overall estimates of the beta coefficients are study year and region for duration and study year and model specification for length. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of safety ratings of roads based on frontal crashes with known crash pulse and injury outcome.

PubMed

Stigson, H

2009-06-01

The objective in this study, using data from crashed cars fitted with on-board crash pulse recorders, was to present differences in average crash severity, distribution of crash severity, and injury outcomes, based on an independent safety rating of roads, also taking road type and speed limit into consideration. Furthermore, the objective was to evaluate differences in injury risk, based on the distribution of crash severity. The investigation included both frontal two-vehicle crashes and single-vehicle crashes with known injury outcome. In total, 209 real-world crashes involving cars fitted with crash pulse recorders were included. For all crashes, average mean acceleration and change of velocity of the vehicle acceleration pulse were measured and calculated. All crash spots were classified according to an independent road safety rating program (European Road Assessment Programme Road Protection Score), where the safety quality of roads is rated in relation to posted speed limits. The crash severity and injury outcome in crashes that occurred on roads with good safety ratings were compared with crashes on roads with poor safety ratings. The data were also divided into subcategories according to posted speed limit and road type, to evaluate whether there was a difference in crash severity and injury outcome within the categories. In total, crash severity was statistically significantly lower in crashes occurring on roads with good safety ratings than in crashes occurring on roads with poor safety ratings. It was found that crash severity and injury risk were lower on roads with good safety ratings with a speed limit of above 90 km/h compared with roads with poor safety ratings, irrespective of speed limit. On the other hand, crash severity was higher on roads with good safety ratings with speed limit of 70 km/h than on roads with poor safety ratings with the same speed limit. Though it was found that a higher speed limit resulted in higher crash severity on roads

76 FR 65769 - Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

... DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority AGENCY: Department of Transportation. ACTION: Notice of Order to... issued to Friendship Airways, Inc. d/b/a Yellow Air Taxi and deny its application to resume commuter...

Lifestyle risk factors for cardiovascular disease and diabetic risk in a sedentary occupational group: the Galway taxi driver study.

PubMed

Martin, W P; Sharif, F; Flaherty, G

2016-05-01

Taxi drivers are at increased risk of cardiovascular disease (CVD), something which persists after correcting for the overrepresentation of traditional risk factors for CVD in this cohort. The contribution of lifestyle risk factors to this residually elevated CVD risk remains under-evaluated. We aimed to determine the prevalence of lifestyle risk factors for CVD, self-reported medical risk factors for CVD, and future risk of type 2 diabetes amongst Irish taxi drivers. Male taxi drivers with no history of CVD and type 2 diabetes and working in Galway city in the west of Ireland were invited to participate. Physical activity levels, dietary patterns, anthropometry, smoking, hypertension, hypercholesterolaemia, and Finnish Diabetes Risk Score (FINDRISC) values were recorded in a cross-sectional manner. 41 taxi drivers (mean age 56.7 ± 9.8 years) participated. 37 % were insufficiently active based on self-report, although only 8 % objectively achieved 10, 000 steps per day. Mean modified Mediterranean diet score (mMDS) was 4.6 ± 2.2, and only 13 % of participants had a normal body mass index (BMI) or waist circumference (WC). Those who worked for taxi companies tended to have a higher BMI (p = .07) and WC (p = .04) by multivariable regression. 22 % were current smokers, although a quit rate of 72 % was observed amongst the 78 % of taxi drivers who had ever smoked. 25 % were at high or very high risk of future type 2 diabetes. Lifestyle risk factors for CVD and dysglycaemia are prevalent amongst Irish taxi drivers.

Crash scene photography in motor vehicle crashes without air bag deployment.

PubMed

Newgard, Craig D; Martens, Katherine A; Lyons, Evelyn M

2002-09-01

To determine whether vehicle characteristics, measured using crash scene photography, are associated with anatomic patterns of injury and severity of injury sustained in motor vehicle crashes (MVCs) without air bag deployment. A prospective observational study was conducted over 22 months, using 12 fire departments serving two hospitals. Two vehicle photographs (exterior and interior) were taken at each MVC. Vehicular variables were assigned by grading the photographs with a standardized scoring system, and outcome information on each patient was collected by chart review. Five hundred fifty-nine patients were entered into the study. Frontal crashes and increasing passenger space intrusion (PSI) were associated with head, facial, and lower-extremity injuries, while rear crashes were associated with spinal injuries. Restraint use had a protective effect in head, facial, and upper and lower extremity injuries, yet was associated with higher odds of spinal injury. Lack of restraint use, increasing PSI, and steering wheel deformity were associated with an increased hospital length of stay and hospital charges, yet only steering wheel deformity was associated with increasing injury severity when adjusting for other crash variables. Out-of-hospital variables, as obtained from crash vehicle photography, are associated with injury site, injury severity, hospital length of stay, and hospital charges in patients involved in MVCs without air bag deployment.

Scanning secondary derived crashes from disabled and abandoned vehicle incidents on uninterrupted flow highways.

PubMed

Chimba, Deo; Kutela, Boniphace

2014-09-01

Extent of secondary crashes derived from primary incidents involving abandoned and disabled vehicles are presented in this paper. Using years 2004 to 2010 incident and crash data on selected Tennessee freeways, the study identified secondary crashes that resulted from disabled and abandoned vehicle primary incidents. The relationship between time and distance gaps before the secondary crash with respect to individual incident characteristics were evaluated through descriptive statistics and linear regression. The time and distance gap analysis indicated that a large portion of secondary crashes occurred within 20 min after the primary incidents and within a distance of 0.5 miles upstream. While 76% of incidents involved shoulder, most secondary crashes were related to the closing of right lanes. Overall, 58% of the secondary crashes occurred within 30 min after the occurrence of the primary incidents. Most of the vehicles in the incidents that involved towing and caused secondary crashes were towed or removed out of the travel way within 60 min from the time of occurrence. The study found that most (95%) secondary crashes were property damage only (PDO), while 49% were rear-end crashes. The negative binomial model was used to evaluate the impact of roadway geometry and traffic factors associated with frequency of these secondary crashes. It was found that the posted speed limit, congested segments, segments with high percentages of trucks, and peak hour volumes increased the likelihood of secondary crash occurrence. Roadway segments with wider medians, shoulders, and multilanes decrease the likelihood of secondary crashes caused by abandoned and disabled vehicles as the primary incidents. Practical applications The paper recommends that wider shoulders be provided on any section of freeway to accommodate abandoned or disabled vehicles to avoid blocking of travel lane(s). Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

The Aircraft Electric Taxi System: A Qualitative Multi Case Study

NASA Astrophysics Data System (ADS)

Johnson, Thomas Frank

The problem this research addresses is the airline industry, and the seemingly unwillingness attitude towards adopting ways to taxi aircraft without utilizing thrust from the main engines. The purpose of the study was to get a better understanding of the decision-making process of airline executives, in respect to investing in cost saving technology. A qualitative research method is used from personal interviews with 24 airline executives from two major U.S. airlines, related industry journal articles, and aircraft performance data. The following three research questions are addressed. RQ1. Does the cost of jet fuel influence airline executives' decision of adopting the aircraft electric taxi system technology? RQ2 Does the measurable payback period for a return on investment influence airline executives' decision of adopting ETS technology? RQ3. Does the amount of government assistance influence airline executives' decision of adopting ETS technology? A multi case research study design is used with a triangulation technique. The participant perceptions indicate the need to reduce operating costs, they have concerns about investment risk, and they are in favor of future government sponsored performance improvement projects. Based on the framework, findings and implications of this study, a future research paper could focus on the positive environmental effects of the ETS application. A study could be conducted on current airport area air quality and the effects that aircraft main engine thrust taxiing has on the surrounding air quality.

Changes in crash risk following re-timing of traffic signal change intervals.

PubMed

Retting, Richard A; Chapline, Janella F; Williams, Allan F

2002-03-01

More than I million motor vehicle crashes occur annually at signalized intersections in the USA. The principal method used to prevent crashes associated with routine changes in signal indications is employment of a traffic signal change interval--a brief yellow and all-red period that follows the green indication. No universal practice exists for selecting the duration of change intervals, and little is known about the influence of the duration of the change interval on crash risk. The purpose of this study was to estimate potential crash effects of modifying the duration of traffic signal change intervals to conform with values associated with a proposed recommended practice published by the Institute of Transportation Engineers. A sample of 122 intersections was identified and randomly assigned to experimental and control groups. Of 51 eligible experimental sites, 40 (78%) needed signal timing changes. For the 3-year period following implementation of signal timing changes, there was an 8% reduction in reportable crashes at experimental sites relative to those occurring at control sites (P = 0.08). For injury crashes, a 12% reduction at experimental sites relative to those occurring at control sites was found (P = 0.03). Pedestrian and bicycle crashes at experimental sites decreased 37% (P = 0.03) relative to controls. Given these results and the relatively low cost of re-timing traffic signals, modifying the duration of traffic signal change intervals to conform with values associated with the Institute of Transportation Engineers' proposed recommended practice should be strongly considered by transportation agencies to reduce the frequency of urban motor vehicle crashes.

Ground Taxi Navigation Problems and Training Solutions

NASA Technical Reports Server (NTRS)

Quinn, Cheryl; Walter, Kim E.; Rosekind, Mark (Technical Monitor)

1997-01-01

Adverse weather conditions can put considerable strain on the National Airspace System. Even small decreases in visibility on the airport surface can create delays, hinder safe movement and lead to errors. Studies of Aviation Safety Reporting System (ASRS) surface movement incidents support the need for technologies and procedures to improve ground operations in low-visibility conditions. This study examined 139 ASRS reports of low-visibility surface movement incidents at 10 major U.S. airports. Errors were characterized in terms of incident type, contributing factors and consequences. The incidents in the present sample were comprised of runway transgressions, taxiway excursions and ground conflicts. The primary contributing factors were Airport Layout and Markings, Communication and Distraction. In half the incidents the controller issued a new clearance or the flight crew took an evasive action and in the remaining half, no recovery attempt was made because the error was detected after the fact. By gaining a better understanding the factors that affect crew navigation in low visibility and the types of errors that are likely to occur, it will be possible to develop more robust technologies to aid pilots in the ground taxi task. Implications for crew training and procedure development for low-visibility ground taxi are also discussed.

Step On It! - Workplace cardiovascular risk assessment of New York City yellow taxi drivers

PubMed Central

Gany, Francesca; Bari, Sehrish; Gill, Pavan; Ramirez, Julia; Ayash, Claudia; Loeb, Rebecca; Aragones, Abraham; Leng, Jennifer

2015-01-01

Background Multiple factors associated with taxi driving can increase the risk of cardiovascular disease (CVD) in taxi drivers. Methods This paper describes the results of Step On It!, which assessed CVD risk factors among New York City taxi drivers at John F. Kennedy International Airport. Drivers completed an intake questionnaire and free screenings for blood pressure, glucose and body mass index (BMI). Results 466 drivers participated. 9% had random plasma glucose values >200 mg/dl. 77% had elevated BMIs. Immigrants who lived in the U.S. for >10 years had 2.5 times the odds (CI: 1.1–5.9) of having high blood pressure compared to newer immigrants. Discussion Abnormalities documented in this study were significant, especially for immigrants with greater duration of residence in the U.S., and underscore the potential for elevated CVD risk in this vulnerable population, and the need to address this risk through frameworks that utilize multiple levels of intervention. PMID:25680879

Relationship of Near-Crash/Crash Risk to Time Spent on a Cell Phone While Driving.

PubMed

Farmer, Charles M; Klauer, Sheila G; McClafferty, Julie A; Guo, Feng

2015-01-01

The objective of this study was to examine in a naturalistic driving setting the dose-response relationship between cell phone usage while driving and risk of a crash or near crash. How is the increasing use of cell phones by drivers associated with overall near-crash/crash risk (i.e., during driving times both on and off the phone)? Day-to-day driving behavior of 105 volunteer subjects was monitored over a period of 1 year. A random sample was selected comprised of 4 trips from each month that each driver was in the study, and in-vehicle video was used to classify driver behavior. The proportion of driving time spent using a cell phone was estimated for each 3-month period and correlated with overall crash and near-crash rates for each period. Thus, it was possible to test whether changes in an individual driver's cell phone use over time were associated with changes in overall near-crash/crash risk. Drivers in the study spent 11.7% of their driving time interacting with a cell phone, primarily talking on the phone (6.5%) or simply holding the phone in their hand or lap (3.7%). The risk of a near-crash/crash event was approximately 17% higher when the driver was interacting with a cell phone, due primarily to actions of reaching for/answering/dialing, which nearly triples risk (relative risk = 2.84). However, the amount of driving time spent interacting with a cell phone did not affect a driver's overall near-crash/crash risk. Vehicle speeds within 6 s of the beginning of each call on average were 5-6 mph lower than speeds at other times. Results of this naturalistic driving study are consistent with the observation that increasing cell phone use in the general driving population has not led to increased crash rates. Although cell phone use can be distracting and crashes have occurred during this distraction, overall crash rates appear unaffected by changes in the rate of cell phone use, even for individual drivers. Drivers compensate somewhat for the distraction

Pre-crash scenarios at road junctions: A clustering method for car crash data.

PubMed

Nitsche, Philippe; Thomas, Pete; Stuetz, Rainer; Welsh, Ruth

2017-10-01

Given the recent advancements in autonomous driving functions, one of the main challenges is safe and efficient operation in complex traffic situations such as road junctions. There is a need for comprehensive testing, either in virtual simulation environments or on real-world test tracks. This paper presents a novel data analysis method including the preparation, analysis and visualization of car crash data, to identify the critical pre-crash scenarios at T- and four-legged junctions as a basis for testing the safety of automated driving systems. The presented method employs k-medoids to cluster historical junction crash data into distinct partitions and then applies the association rules algorithm to each cluster to specify the driving scenarios in more detail. The dataset used consists of 1056 junction crashes in the UK, which were exported from the in-depth "On-the-Spot" database. The study resulted in thirteen crash clusters for T-junctions, and six crash clusters for crossroads. Association rules revealed common crash characteristics, which were the basis for the scenario descriptions. The results support existing findings on road junction accidents and provide benchmark situations for safety performance tests in order to reduce the possible number parameter combinations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhancing taxi performance under low visibility : are moving maps enough?

DOT National Transportation Integrated Search

1997-09-01

We report the results of an experiment evaluating the separate and combined effects of a 3-D perspective moving map and newly developed Head-Up Display symbology on taxi performance in low visibility. Nine commercial airline pilots completed a series...

Late-Night Shared-Ride Taxi Transit in Ann Arbor, MI

DOT National Transportation Integrated Search

1984-10-01

The Ann Arbor Transportation Authority introduced Night Ride, a late-night shared-ride taxi transit service, in mid-March 1982. The service was provided through a contract with a local taxicab company and funded through a demonstration grant from the...

The xylanase inhibitor TAXI-III counteracts the necrotic activity of a Fusarium graminearum xylanase in vitro and in durum wheat transgenic plants.

PubMed

Moscetti, Ilaria; Faoro, Franco; Moro, Stefano; Sabbadin, Davide; Sella, Luca; Favaron, Francesco; D'Ovidio, Renato

2015-08-01

The xylanase inhibitor TAXI-III has been proven to delay Fusarium head blight (FHB) symptoms caused by Fusarium graminearum in transgenic durum wheat plants. To elucidate the molecular mechanism underlying the capacity of the TAXI-III transgenic plants to limit FHB symptoms, we treated wheat tissues with the xylanase FGSG_03624, hitherto shown to induce cell death and hydrogen peroxide accumulation. Experiments performed on lemmas of flowering wheat spikes and wheat cell suspension cultures demonstrated that pre-incubation of xylanase FGSG_03624 with TAXI-III significantly decreased cell death. Most interestingly, a reduced cell death relative to control non-transgenic plants was also obtained by treating, with the same xylanase, lemmas of TAXI-III transgenic plants. Molecular modelling studies predicted an interaction between the TAXI-III residue H395 and residues E122 and E214 belonging to the active site of xylanase FGSG_03624. These results provide, for the first time, clear indications in vitro and in planta that a xylanase inhibitor can prevent the necrotic activity of a xylanase, and suggest that the reduced FHB symptoms on transgenic TAXI-III plants may be a result not only of the direct inhibition of xylanase activity secreted by the pathogen, but also of the capacity of TAXI-III to avoid host cell death. © 2014 BSPP AND JOHN WILEY & SONS LTD.

The prevalence of fatigue and associated health and safety risk factors among taxi drivers in Singapore

PubMed Central

Lim, See Ming; Chia, Sin Eng

2015-01-01

INTRODUCTION Driver fatigue is one of the biggest health and safety concerns within the road transport sector. This study aimed to determine the prevalence of fatigue among taxi drivers in Singapore, to better understand the general working and health conditions of this group of people, and to determine the risk factors associated with fatigued driving. METHODS A total of 340 taxi drivers were randomly selected for participation in a self-administered questionnaire survey, which included height and weight measurements. The response rate was 68.2%. The survey consisted of four main categories: personal particulars; social habits; work patterns; and sleep profile. The Epworth Sleepiness Scale was used to estimate the level of daytime sleepiness and fatigue. Multiple logistic regression analysis was used to estimate the adjusted odd ratios and 95% confidence intervals associated with risk factors related to fatigue among taxi drivers. RESULTS A high proportion of taxi drivers were obese and had self-reported hypertension, diabetes mellitus and high cholesterol. Driver fatigue was associated with very poor/poor self-rating of quality of sleep, having an additional part-time job, drinking three or more caffeinated drinks daily, and driving more than 10 hours a day. CONCLUSION We hope that the findings of the present study will improve awareness of the work and health conditions of taxi drivers, and contribute toward efforts to achieve a healthier workforce. A lower prevalence of fatigued driving may lead to lower risks of road traffic accidents, decreased economic loss, increased productivity, and safer roads for all. PMID:25532512

The prevalence of fatigue and associated health and safety risk factors among taxi drivers in Singapore.

PubMed

Lim, See Ming; Chia, Sin Eng

2015-02-01

Driver fatigue is one of the biggest health and safety concerns within the road transport sector. This study aimed to find out the prevalence of fatigue among taxi drivers in Singapore, to better understand the general working and health conditions of this group of people and to determine the risk factors associated with fatigued driving. A total of 340 taxi drivers were randomly selected for participation in this self-administered questionnaire survey, with height and weight measurements. The response rate was 68.2%. The survey consisted of four main categories: personal particulars; social habits; work patterns and sleep profile; and Epworth Sleepiness Scale, which was used to estimate the level of daytime sleepiness and fatigue. Multiple logistic regression analysis was used to estimate the adjusted odd ratios and 95% confidence intervals associated with the risk factors related to fatigue among the taxi drivers. A high proportion of the taxi drivers were obese and had self-reported hypertension, diabetes mellitus and high cholesterol. Driver fatigue was associated with very poor/poor self-rating of the quality of sleep, having an additional part-time job, drinking three or more caffeinated drinks daily, and driving more than 10 hours a day. We hope that the findings of the present study will improve the awareness regarding the work and health conditions of taxi drivers, and contribute toward the effort to achieve a healthier workforce. A lower prevalence of fatigued driving will lead to lower risks of road traffic accidents, decreased economic loss, increased productivity, and safer roads for all.

Overloading among crash-involved vehicles in China: identification of factors associated with overloading and crash severity.

PubMed

Zhang, Guangnan; Li, Yanyan; King, Mark J; Zhong, Qiaoting

2018-03-21

Motor vehicle overloading is correlated with the possibility of road crash occurrence and severity. Although overloading of motor vehicles is pervasive in developing nations, few empirical analyses have been performed on factors that might influence the occurrence of overloading. This study aims to address this shortcoming by seeking evidence from several years of crash data from Guangdong province, China. Data on overloading and other factors are extracted for crash-involved vehicles from traffic crash records for 2006-2010 provided by the Traffic Management Bureau in Guangdong province. Logistic regression is applied to identify risk factors for overloading in crash-involved vehicles and within these crashes to identify factors contributing to greater crash severity. Driver, vehicle, road and environmental characteristics and violation types are considered in the regression models. In addition to the basic logistic models, association analysis is employed to identify the potential interactions among different risk factors during fitting the logistic models of overloading and severity. Crash-involved vehicles driven by males from rural households and in an unsafe condition are more likely to be overloaded and to be involved in higher severity overloaded vehicle crashes. If overloaded vehicles speed, the risk of severe traffic crash casualties increases. Young drivers (aged under 25 years) in mountainous areas are more likely to be involved in higher severity overloaded vehicle crashes. This study identifies several factors associated with overloading in crash-involved vehicles and with higher severity overloading crashes and provides an important reference for future research on those specific risk factors. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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

Compliance and enforcement of a partial smoking ban in Lisbon taxis: an exploratory cross-sectional study

PubMed Central

2013-01-01

Background Research evaluating enforcement and compliance with smoking partial bans is rather scarce, especially in countries with relative weak tobacco control policies, such as Portugal. There is also scarce evidence on specific high risk groups such as vehicle workers. In January 2008, Portugal implemented a partial ban, followed by poor enforcement. The purpose of this study was to explore the effectiveness of a partial smoking ban in a pro-smoking environment, specifically transportation by taxi in the city of Lisbon. Ban effectiveness was generally defined by ban awareness and support, compliance and enforcement. Methods Exploratory cross-sectional study; purposive sampling in selected Lisbon streets. Structured interviews were conducted by trained researchers while using taxi services (January 2009-December 2010). Participants: 250 taxi drivers (98.8% participation rate). Chi-square, McNemar, Man Whitney tests and multiple logistic regression were performed. Results Of the participants, 249 were male; median age was 53.0 years; 43.6% were current smokers. Most participants (82.8%) approved comprehensive bans; 84.8% reported that clients still asked to smoke in their taxis; 16.8% allowed clients to smoke. Prior to the ban this value was 76.9% (p < 0.001). The major reason for not allowing smoking was the legal ban and associated fines (71.2%). Of the smokers, 66.1% admitted smoking in their taxi. Stale smoke smells were detected in 37.6% of the cars. None of the taxi drivers did ever receive a fine for non-compliance. Heavy smoking, night-shift and allowing smoking prior the ban predicted non-compliance. Conclusions Despite the strong ban support observed, high smoking prevalence and poor enforcement contribute to low compliance. The findings also suggest low compliance among night-shift and vehicle workers. This study clearly demonstrates that a partial and poorly-enforced ban is vulnerable to breaches, and highlights the need for clear and strong

Comprehensive and human capital crash costs by maximum police-reported injury severity within selected crash types.

PubMed

Zaloshnja, Eduard; Miller, Ted; Council, Forrest; Persaud, Bhagwant

2004-01-01

This paper presents estimates for both the economic and comprehensive costs per crash for three police-coded severity groupings within 16 selected crash types and within two speed limit categories (or=50 mph). The economic costs are hard dollar costs. The comprehensive costs include economic costs and quality of life losses. We merged previously developed costs per victim keyed on the Abbreviated Injury Scale (AIS) into US crash data files that scored injuries in both the AIS and police-coded severity scales to produce per crash estimates. The most costly crashes were non-intersection fatal/disabling injury crashes on a road with a speed limit of 50 miles per hour or higher where multiple vehicles crashed head-on or a single vehicle struck a human (over 1.69 and $1.16 million per crash, respectively). The annual cost of police-reported run-off-road collisions, which include both rollovers and object impacts, represented 34% of total costs.

Comprehensive and Human Capital Crash Costs by Maximum Police-Reported Injury Severity Within Selected Crash Types

PubMed Central

Zaloshnja, Eduard; Miller, Ted; Council, Forrest; Persaud, Bhagwant

2004-01-01

This paper presents estimates for both the economic and comprehensive costs per crash for three police-coded severity groupings within 16 selected crash types and within two speed limit categories (<=45 and >=50 mph). The economic costs are hard dollar costs. The comprehensive costs include economic costs and quality of life losses. We merged previously developed costs per victim keyed on the Abbreviated Injury Scale (AIS) into US crash data files that scored injuries in both the AIS and police-coded severity scales to produce per crash estimates. The most costly crashes were non-intersection fatal/disabling injury crashes on a road with a speed limit of 50 miles per hour or higher where multiple vehicles crashed head-on or a single vehicle struck a human (over 1.69 and $1.16 million per crash, respectively). The annual cost of police-reported run-off-road collisions, which include both rollovers and object impacts, represented 34% of total costs. PMID:15319129

Crash countermeasure and mobility effects.

DOT National Transportation Integrated Search

2012-04-19

The Michigan Department of Transportation (MDOT) has undertaken several initiatives to reduce crashes on its roadway network. In 2009, there were 2,201 reported crashes involving pedestrians and 866 reported crashes involving bicyclists in Michigan. ...

An investigation of the speeding-related crash designation through crash narrative reviews sampled via logistic regression.

PubMed

Fitzpatrick, Cole D; Rakasi, Saritha; Knodler, Michael A

2017-01-01

Speed is one of the most important factors in traffic safety as higher speeds are linked to increased crash risk and higher injury severities. Nearly a third of fatal crashes in the United States are designated as "speeding-related", which is defined as either "the driver behavior of exceeding the posted speed limit or driving too fast for conditions." While many studies have utilized the speeding-related designation in safety analyses, no studies have examined the underlying accuracy of this designation. Herein, we investigate the speeding-related crash designation through the development of a series of logistic regression models that were derived from the established speeding-related crash typologies and validated using a blind review, by multiple researchers, of 604 crash narratives. The developed logistic regression model accurately identified crashes which were not originally designated as speeding-related but had crash narratives that suggested speeding as a causative factor. Only 53.4% of crashes designated as speeding-related contained narratives which described speeding as a causative factor. Further investigation of these crashes revealed that the driver contributing code (DCC) of "driving too fast for conditions" was being used in three separate situations. Additionally, this DCC was also incorrectly used when "exceeding the posted speed limit" would likely have been a more appropriate designation. Finally, it was determined that the responding officer only utilized one DCC in 82% of crashes not designated as speeding-related but contained a narrative indicating speed as a contributing causal factor. The use of logistic regression models based upon speeding-related crash typologies offers a promising method by which all possible speeding-related crashes could be identified. Published by Elsevier Ltd.

Quantifying the impact of adaptive traffic control systems on crash frequency and severity: Evidence from Oakland County, Michigan.

PubMed

Fink, Joshua; Kwigizile, Valerian; Oh, Jun-Seok

2016-06-01

Despite seeing widespread usage worldwide, adaptive traffic control systems have experienced relatively little use in the United States. Of the systems used, the Sydney Coordinated Adaptive Traffic System (SCATS) is the most popular in America. Safety benefits of these systems are not as well understood nor as commonly documented. This study investigates the safety benefits of adaptive traffic control systems by using the large SCATS-based system in Oakland County, MI known as FAST-TRAC. This study uses data from FAST-TRAC-controlled intersections in Oakland County and compares a wide variety of geometric, traffic, and crash characteristics to similar intersections in metropolitan areas elsewhere in Michigan. Data from 498 signalized intersections are used to conduct a cross-sectional analysis. Negative binomial models are used to estimate models for three dependent crash variables. Multinomial logit models are used to estimate an injury severity model. A variable tracking the presence of FAST-TRAC controllers at intersections is used in all models to determine if a SCATS-based system has an impact on crash occurrences or crash severity. Estimates show that the presence of SCATS-based controllers at intersections is likely to reduce angle crashes by up to 19.3%. Severity results show a statistically significant increase in non-serious injuries, but not a significant reduction in incapacitating injuries or fatal accidents. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

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

Taxi Regulatory Revision in San Diego, California : Background and Implementation

DOT National Transportation Integrated Search

1981-07-01

Starting in January, 1979, the San Diego City Council revised its paratransit regulations and began issuing 6 new taxi permits per month. As of July, 1979, the ratio of new permit issuance was increased to 15 per month. Effective August 1, 1979, the ...

Traffic crash statistics report, 2005

DOT National Transportation Integrated Search

2006-01-01

The information contained in this Traffic Crash Statistics booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form : crash report when investigating: : Motor vehic...

Large truck crash facts 2005

DOT National Transportation Integrated Search

2007-02-01

This annual edition of Large Truck Crash Facts contains descriptive statistics about fatal, injury, and property damage only crashes involving large trucks in 2005. Selected crash statistics on passenger vehicles are also presented for comparison pur...

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

Data needs for tree removal crash modification factors on Arizona state highways.

DOT National Transportation Integrated Search

2016-07-01

The Arizona Department of Transportation (ADOT) Roadway Departure Safety Implementation Plan (RDSIP) has : identified tree removal as a feasible countermeasure to reduce roadway departure crash frequency or severity. : Previous ADOT work has identifi...

14 CFR 25.491 - Taxi, takeoff and landing roll.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Taxi, takeoff and landing roll. 25.491..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the...

14 CFR 25.491 - Taxi, takeoff and landing roll.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Taxi, takeoff and landing roll. 25.491..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the...

Motor vehicle-bicycle crashes in Beijing: irregular maneuvers, crash patterns, and injury severity.

PubMed

Yan, Xinping; Ma, Ming; Huang, Helai; Abdel-Aty, Mohamed; Wu, Chaozhong

2011-09-01

This research presents a comprehensive analysis of motor vehicle-bicycle crashes using 4 years of reported crash data (2004-2007) in Beijing. The interrelationship of irregular maneuvers, crash patterns and bicyclist injury severity are investigated by controlling for a variety of risk factors related to bicyclist demographics, roadway geometric design, road environment, etc. Results show that different irregular maneuvers are correlated with a number of risk factors at different roadway locations such as the bicyclist age and gender, weather and traffic condition. Furthermore, angle collisions are the leading pattern of motor vehicle-bicycle crashes, and different irregular maneuvers may lead to some specific crash patterns such as head-on or rear-end crashes. Orthokinetic scrape is more likely to result in running over bicyclists, which may lead to more severe injury. Moreover, bicyclist injury severity level could be elevated by specific crash patterns and risk factors including head-on and angle collisions, occurrence of running over bicyclists, night without streetlight, roads without median/division, higher speed limit, heavy vehicle involvement and older bicyclists. This study suggests installation of median, division between roadway and bikeway, and improvement of illumination on road segments. Reduced speed limit is also recommended at roadway locations with high bicycle traffic volume. Furthermore, it may be necessary to develop safety campaigns aimed at male, teenage and older bicyclists. Copyright © 2011 Elsevier Ltd. All rights reserved.

Labeling Residential Community Characteristics from Collective Activity Patterns Using Taxi Trip Data

NASA Astrophysics Data System (ADS)

Zhou, Y.; Fang, Z.

2017-09-01

There existing a significant social and spatial differentiation in the residential communities in urban city. People live in different places have different socioeconomic background, resulting in various geographically activity patterns. This paper aims to label the characteristics of residential communities in a city using collective activity patterns derived from taxi trip data. Specifically, we first present a method to allocate the O/D (Origin/Destination) points of taxi trips to the land use parcels where the activities taken place in. Then several indices are employed to describe the collective activity patterns, including both activity intensity, travel distance, travel time, and activity space of residents by taking account of the geographical distribution of all O/Ds of the taxi trip related to that residential community. Followed by that, an agglomerative hierarchical clustering algorithm is introduced to cluster the residential communities with similar activity patterns. In the case study of Wuhan, the residential communities are clearly divided into eight clusters, which could be labelled as ordinary communities, privileged communities, old isolated communities, suburban communities, and so on. In this paper, we provide a new perspective to label the land use under same type from people's mobility patterns with the support of big trajectory data.

Crashes of sightseeing helicopter tours in Hawaii.

PubMed

Haaland, Wren L; Shanahan, Dennis F; Baker, Susan P

2009-07-01

Crashes of sightseeing helicopter flights in Hawaii and the resulting tourist deaths prompted the FAA to issue regulations in 1994 specific to air tours in Hawaii. Research was undertaken to examine the effect of the 1994 Rule and to describe the circumstances of such crashes. From National Transportation Safety Board data, 59 crashes of helicopter air tour flights in Hawaii during 1981-2008 were identified; crash investigation reports were read and coded. Crashes in 1995-2008 were compared with those in 1981-1994. The 1994 Rule was followed by a 47% decrease in the crash rate, from 3.4 to 1.8/100,000 flight hours. The number of crashes into the ocean decreased from eight before the Rule to one afterwards. VFR-IMC crashes increased from 5 to 32% of crashes. There were 46 tourists and 9 pilots who died in 16 fatal crashes. Aircraft malfunctions, primarily due to poor maintenance, precipitated 34 (58%) of the crashes and persisted throughout the 28-yr period. Pilot errors were apparent in 23 crashes (39%). Flight from visual to instrument conditions occurred in two cases before the Rule and seven cases after. Terrain unsuitable for landing was cited in 37 crashes (63%). Decreases occurred in the overall number and rate of crashes and in ocean crash landings. The increase in VFR-IMC crashes may be related to the requirement that tour helicopters fly at least 1500 ft. above terrain. Attention is still needed to maintenance, pilot training, and restricting flights to operating areas and conditions that enable safe emergency landings.

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. Published by Elsevier Ltd.

Fuel Consumption and Emissions from Airport Taxi Operations

NASA Technical Reports Server (NTRS)

Jung, Yoon

2010-01-01

Developed a method to calculate fuel consumption and emissions of phases of taxi operations. Results at DFW showed that up to 18% of fuel can be saved by eliminating stop-and-go situations. Developed an energy efficient and environmentally friendly surface concept: Spot and Runway Departure Advisory (SARDA) tool. The SARDA tool has been identified as a potential candidate for a technology transfer to the FAA.

Analysis of Driver Evasive Maneuvering Prior to Intersection Crashes Using Event Data Recorders.

PubMed

Scanlon, John M; Kusano, Kristofer D; Gabler, Hampton C

2015-01-01

Intersection crashes account for over 4,500 fatalities in the United States each year. Intersection Advanced Driver Assistance Systems (I-ADAS) are emerging vehicle-based active safety systems that have the potential to help drivers safely navigate across intersections and prevent intersection crashes and injuries. The performance of an I-ADAS is expected to be highly dependent upon driver evasive maneuvering prior to an intersection crash. Little has been published, however, on the detailed evasive kinematics followed by drivers prior to real-world intersection crashes. The objective of this study was to characterize the frequency, timing, and kinematics of driver evasive maneuvers prior to intersection crashes. Event data recorders (EDRs) downloaded from vehicles involved in intersection crashes were investigated as part of NASS-CDS years 2001 to 2013. A total of 135 EDRs with precrash vehicle speed and braking application were downloaded to investigate evasive braking. A smaller subset of 59 EDRs that collected vehicle yaw rate was additionally analyzed to investigate evasive steering. Each vehicle was assigned to one of 3 precrash movement classifiers (traveling through the intersection, completely stopped, or rolling stop) based on the vehicle's calculated acceleration and observed velocity profile. To ensure that any significant steering input observed was an attempted evasive maneuver, the analysis excluded vehicles at intersections that were turning, driving on a curved road, or performing a lane change. Braking application at the last EDR-recorded time point was assumed to indicate evasive braking. A vehicle yaw rate greater than 4° per second was assumed to indicate an evasive steering maneuver. Drivers executed crash avoidance maneuvers in four-fifths of intersection crashes. A more detailed analysis of evasive braking frequency by precrash maneuver revealed that drivers performing complete or rolling stops (61.3%) braked less often than drivers

Statistical analysis of vehicle crashes in Mississippi based on crash data from 2010 to 2014.

DOT National Transportation Integrated Search

2017-08-15

Traffic crash data from 2010 to 2014 were collected by Mississippi Department of Transportation (MDOT) and extracted for the study. Three tasks were conducted in this study: (1) geographic distribution of crashes; (2) descriptive statistics of crash ...

New Jersey Crash Record Geocoding : Improving the State's Crash Database to Enhance Data‐Driven Decisions

DOT National Transportation Integrated Search

2010-06-01

The New Jersey Crash Record Geocoding Initiative was designed as a provisional measure to address missing crash locations. The purpose of the initiative was twofold. Primarily, students worked to locate crashes that had no location information after ...

Design Reference Missions (DRM): Integrated ODM 'Air-Taxi' Mission Features

NASA Technical Reports Server (NTRS)

Kloesel, Kurt; Starr, Ginn; Saltzman, John A.

2017-01-01

Design Reference Missions (DRM): Integrated ODM Air-Taxi Mission Features, Hybrid Electric Integrated System Testbed (HEIST) flight control. Structural Health, Energy Storage, Electric Components, Loss of Control, Degraded Systems, System Health, Real-Time IO Operator Geo-Fencing, Regional Noise Abatement and Trusted Autonomy Inter-operability.

2004 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2005-07-01

2004 Facts and Figures - 784 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of two lives lost each day on Wisconsin trafficways. - 55,258 persons were injured in 38,451 reported injury crashes and 714 fatal crashes...

Safe speed limits for a safe system: The relationship between speed limit and fatal crash rate for different crash types.

PubMed

Doecke, Sam D; Kloeden, Craig N; Dutschke, Jeffrey K; Baldock, Matthew R J

2018-05-19

The objective of this article is to provide empirical evidence for safe speed limits that will meet the objectives of the Safe System by examining the relationship between speed limit and injury severity for different crash types, using police-reported crash data. Police-reported crashes from 2 Australian jurisdictions were used to calculate a fatal crash rate by speed limit and crash type. Example safe speed limits were defined using threshold risk levels. A positive exponential relationship between speed limit and fatality rate was found. For an example fatality rate threshold of 1 in 100 crashes it was found that safe speed limits are 40 km/h for pedestrian crashes; 50 km/h for head-on crashes; 60 km/h for hit fixed object crashes; 80 km/h for right angle, right turn, and left road/rollover crashes; and 110 km/h or more for rear-end crashes. The positive exponential relationship between speed limit and fatal crash rate is consistent with prior research into speed and crash risk. The results indicate that speed zones of 100 km/h or more only meet the objectives of the Safe System, with regard to fatal crashes, where all crash types except rear-end crashes are exceedingly rare, such as on a high standard restricted access highway with a safe roadside design.

2010 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2011-01-01

562 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of just over one life lost each day on Wisconsin traffic arteries. : 40,889 persons were injured in 29,380 reported injury crashes and 517 fatal crashes. 3,845, or...

The October 2014 United States Treasury bond flash crash and the contributory effect of mini flash crashes

PubMed Central

Levine, Zachary S.; Floridi, Luciano

2017-01-01

We investigate the causal uncertainty surrounding the flash crash in the U.S. Treasury bond market on October 15, 2014, and the unresolved concern that no clear link has been identified between the start of the flash crash at 9:33 and the opening of the U.S. equity market at 9:30. We consider the contributory effect of mini flash crashes in equity markets, and find that the number of equity mini flash crashes in the three-minute window between market open and the Treasury Flash Crash was 2.6 times larger than the number experienced in any other three-minute window in the prior ten weekdays. We argue that (a) this statistically significant finding suggests that mini flash crashes in equity markets both predicted and contributed to the October 2014 U.S. Treasury Bond Flash Crash, and (b) mini-flash crashes are important phenomena with negative externalities that deserve much greater scholarly attention. PMID:29091931

Spatial analysis to identify high risk areas for traffic crashes resulting in death of pedestrians in Tehran

PubMed Central

Moradi, Ali; Soori, Hamid; Kavousi, Amir; Eshghabadi, Farshid; Jamshidi, Ensiyeh; Zeini, Salahdien

2016-01-01

Background: More than 20% of deaths from traffic crashes are related to pedestrians. This figure in Tehran, the capital of Iran, reaches to 40%. This study aimed to determine the high-risk areas and spatially analyze the traffic crashes, causing death to pedestrians in Tehran. Methods: Mapping was used to display the distribution of the crashes. Determining the distribution pattern of crashes and the hot spots/ low-risk areas were done, using Moran’s I index and Getis-Ord G, respectively. Results: A total of 198 crashes were studied; 92 of which, (46.4%) occurred in 2013 to 2014 and other 106 cases (63.6%) occurred in 2014 to 2015. The highest and the lowest frequency of crashes was related to January (26 cases) and June (10 cases), respectively. One hundred fifty- eight cases (79.8%) of crashes occurred in Tehran highways. Moran’s index showed that the studied traffic crashes had a cluster distribution (p<0.001). Getis- Ord General G index indicated that the distribution of hot and cold spots of the studied crashes was statistically significant (p<0.001). Conclusion: The majority of traffic crashes causing death to pedestrians occurred in highways located in the main entrances and exits of Tehran. Given the important role of environmental factors in the occurrence of traffic crashes related to pedestrians, identification of these factors requires more studies with casual inferences. PMID:28210615

Wrong-way driving crashes: A random-parameters ordered probit analysis of injury severity.

PubMed

Jalayer, Mohammad; Shabanpour, Ramin; Pour-Rouholamin, Mahdi; Golshani, Nima; Zhou, Huaguo

2018-04-23

In the context of traffic safety, whenever a motorized road user moves against the proper flow of vehicle movement on physically divided highways or access ramps, this is referred to as wrong-way driving (WWD). WWD is notorious for its severity rather than frequency. Based on data from the U.S. National Highway Traffic Safety Administration, an average of 355 deaths occur in the U.S. each year due to WWD. This total translates to 1.34 fatalities per fatal WWD crashes, whereas the same rate for other crash types is 1.10. Given these sobering statistics, WWD crashes, and specifically their severity, must be meticulously analyzed using the appropriate tools to develop sound and effective countermeasures. The objectives of this study were to use a random-parameters ordered probit model to determine the features that best describe WWD crashes and to evaluate the severity of injuries in WWD crashes. This approach takes into account unobserved effects that may be associated with roadway, environmental, vehicle, crash, and driver characteristics. To that end and given the rareness of WWD events, 15 years of crash data from the states of Alabama and Illinois were obtained and compiled. Based on this data, a series of contributing factors including responsible driver characteristics, temporal variables, vehicle characteristics, and crash variables are determined, and their impacts on the severity of injuries are explored. An elasticity analysis was also performed to accurately quantify the effect of significant variables on injury severity outcomes. According to the obtained results, factors such as driver age, driver condition, roadway surface conditions, and lighting conditions significantly contribute to the injury severity of WWD crashes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Multivariate poisson lognormal modeling of crashes by type and severity on rural two lane highways.

PubMed

Wang, Kai; Ivan, John N; Ravishanker, Nalini; Jackson, Eric

2017-02-01

In an effort to improve traffic safety, there has been considerable interest in estimating crash prediction models and identifying factors contributing to crashes. To account for crash frequency variations among crash types and severities, crash prediction models have been estimated by type and severity. The univariate crash count models have been used by researchers to estimate crashes by crash type or severity, in which the crash counts by type or severity are assumed to be independent of one another and modelled separately. When considering crash types and severities simultaneously, this may neglect the potential correlations between crash counts due to the presence of shared unobserved factors across crash types or severities for a specific roadway intersection or segment, and might lead to biased parameter estimation and reduce model accuracy. The focus on this study is to estimate crashes by both crash type and crash severity using the Integrated Nested Laplace Approximation (INLA) Multivariate Poisson Lognormal (MVPLN) model, and identify the different effects of contributing factors on different crash type and severity counts on rural two-lane highways. The INLA MVPLN model can simultaneously model crash counts by crash type and crash severity by accounting for the potential correlations among them and significantly decreases the computational time compared with a fully Bayesian fitting of the MVPLN model using Markov Chain Monte Carlo (MCMC) method. This paper describes estimation of MVPLN models for three-way stop controlled (3ST) intersections, four-way stop controlled (4ST) intersections, four-way signalized (4SG) intersections, and roadway segments on rural two-lane highways. Annual Average Daily traffic (AADT) and variables describing roadway conditions (including presence of lighting, presence of left-turn/right-turn lane, lane width and shoulder width) were used as predictors. A Univariate Poisson Lognormal (UPLN) was estimated by crash type and

Spatially referenced crash data system for application to commercial motor vehicle crashes.

DOT National Transportation Integrated Search

2003-05-01

The Maryland Spatial Analysis of Crashes (MSAC) project involves the design of a : prototype of a geographic information system (GIS) for the State of Maryland that has : the capability of providing online crash information and statistical informatio...

Turing-Hopf bifurcations in a predator-prey model with herd behavior, quadratic mortality and prey-taxis

NASA Astrophysics Data System (ADS)

Liu, Xia; Zhang, Tonghua; Meng, Xinzhu; Zhang, Tongqian

2018-04-01

In this paper, we propose a predator-prey model with herd behavior and prey-taxis. Then, we analyze the stability and bifurcation of the positive equilibrium of the model subject to the homogeneous Neumann boundary condition. By using an abstract bifurcation theory and taking prey-tactic sensitivity coefficient as the bifurcation parameter, we obtain a branch of stable nonconstant solutions bifurcating from the positive equilibrium. Our results show that prey-taxis can yield the occurrence of spatial patterns.

Taxi Regulatory Revision in Oakland and Berkeley, California : Two Case Studies

DOT National Transportation Integrated Search

1983-06-01

A case study was performed of regulatory changes pertaining to taxicabs in Oakland and neighboring Berkeley, CA. In Oakland rates were approximately doubled and limits on the number of taxi permits removed. Companies were allowed to levy a per-trip s...

Visual exploration of big spatio-temporal urban data: a study of New York City taxi trips.

PubMed

Ferreira, Nivan; Poco, Jorge; Vo, Huy T; Freire, Juliana; Silva, Cláudio T

2013-12-01

As increasing volumes of urban data are captured and become available, new opportunities arise for data-driven analysis that can lead to improvements in the lives of citizens through evidence-based decision making and policies. In this paper, we focus on a particularly important urban data set: taxi trips. Taxis are valuable sensors and information associated with taxi trips can provide unprecedented insight into many different aspects of city life, from economic activity and human behavior to mobility patterns. But analyzing these data presents many challenges. The data are complex, containing geographical and temporal components in addition to multiple variables associated with each trip. Consequently, it is hard to specify exploratory queries and to perform comparative analyses (e.g., compare different regions over time). This problem is compounded due to the size of the data-there are on average 500,000 taxi trips each day in NYC. We propose a new model that allows users to visually query taxi trips. Besides standard analytics queries, the model supports origin-destination queries that enable the study of mobility across the city. We show that this model is able to express a wide range of spatio-temporal queries, and it is also flexible in that not only can queries be composed but also different aggregations and visual representations can be applied, allowing users to explore and compare results. We have built a scalable system that implements this model which supports interactive response times; makes use of an adaptive level-of-detail rendering strategy to generate clutter-free visualization for large results; and shows hidden details to the users in a summary through the use of overlay heat maps. We present a series of case studies motivated by traffic engineers and economists that show how our model and system enable domain experts to perform tasks that were previously unattainable for them.

Reporting on cyclist crashes in Australian newspapers.

PubMed

Boufous, Soufiane; Aboss, Ahmad; Montgomery, Victoria

2016-10-01

To assess information on cyclist crashes reported in Australian newspapers. The Factiva news archive was searched for articles on cyclist crashes published in major Australian newspapers between 2010 and 2013. Information on the circumstances of cyclist crashes were extracted and coded. A total of 160 cyclist crashes were covered by 198 newspaper articles, with 44% of crashes resulting in cyclist fatalities. Crashes reported by more than one newspaper were more likely to involve public figures or protracted court cases. Individual characteristics of cyclists as well as the location of the crash were reported for more than 80% of crashes. The road user at fault was reported for more than half of crashes. In contrast, information on helmet use, alcohol and cycling lanes was mentioned for only about 10% of crashes. Fewer than one in five articles mentioned prevention strategies including education campaigns, legislative and infrastructure changes. Australian newspapers tend to focus on the most dramatic and more 'newsworthy' aspects of cyclist crashes. Cycling advocates need to work with journalists to improve the quality of this coverage. Better communication between cycling advocates and journalists is likely to have a positive impact on the safety and the uptake of cycling in the community. © 2016 Public Health Association of Australia.

Risk-Exposure Density and Mileage Bias in Crash Risk for Older Drivers

PubMed Central

Rolison, Jonathan J; Moutari, Salissou

2018-01-01

Abstract Crash rates per mile indicate a high risk of vehicle crash in older drivers. A reliance on mileage alone may underestimate the risk exposure of older drivers because they tend to avoid highways and travel more on nonfreeways (e.g., urban roads), which present greater hazards. We introduce risk-exposure density as an index of exposure that incorporates mileage, frequency of travel, and travel duration. Population-wide driver fatalities in the United States during 2002–2012 were assessed according to driver age range (in years: 16–20, 21–29, 30–39, 40–49, 50–59, 60–69, ≥70) and sex. Mileage, frequency, and duration of travel per person were used to assess risk exposure. Mileage-based fatal crash risk increased greatly among male (relative risk (RR) = 1.73; 95% CI: 1.62, 1.83) and female (RR = 2.08; 95% CI: 1.97, 2.19) drivers from ages 60–69 years to ages ≥70 years. Adjusting for their density of risk exposure, fatal crash risk increased only slightly from ages 60–69 years to ages ≥70 years among male (RR = 1.09; 95% CI: 1.03, 1.15) and female (RR = 1.22; 95% CI: 1.16, 1.29) drivers. While ubiquitous in epidemiologic research, mileage-based assessments can produce misleading accounts of driver risk. Risk-exposure density incorporates multiple components of travel and reduces bias caused by any single indicator of risk exposure. PMID:28605422

Patterns of severe injury in pediatric car crash victims: Crash Injury Research Engineering Network database.

PubMed

Brown, J Kristine; Jing, Yuezhou; Wang, Stewart; Ehrlich, Peter F

2006-02-01

Motor vehicle crashes (MVCs) account for 50% of pediatric trauma. Safety improvements are typically tested with child crash dummies using an in vitro model. The Crash Injury Research Engineering Network (CIREN) provides an in vivo validation process. Previous research suggest that children in lateral crashes or front-seat locations have higher Injury Severity Scale scores and lower Glasgow Coma Scale scores than those in frontal-impact crashes. However, specific injury patterns and crash characteristics have not been characterized. Data were collected from the CIREN multidisciplinary crash reconstruction network (10 pediatric trauma centers). Injuries were examined with regard to crash direction (frontal/lateral), restraint use, seat location, and change in velocity at impact (DeltaV). Injuries were limited to Abbreviated Injury Scale (AIS) scores of 3 or higher and included head, thoracic, abdominal, pelvic, spine, and long bone (orthopedic) injuries. Standard age groupings (0-4, 5-9, 10-14, and 15-18 years) were used. Statistical analyses used Fisher's Exact test and multiple logistic regressions. Four hundred seventeen MVCs with 2500 injuries were analyzed (males = 219, females = 198). Controlling for DeltaV and age, children in lateral-impact crashes (n = 232) were significantly more likely to suffer severe injuries to the head and thorax as compared with children in frontal crashes (n = 185), who were more likely to suffer severe spine and orthopedic injuries. Children in a front-seat (n = 236) vs those in a back-seat (n = 169) position had more injuries to the thoracic (27% vs 17%), abdominal (21% vs 13%), pelvic (11% vs 1%), and orthopedic (28% vs 10%) regions (P < .05 for all). Seat belts were protective for pelvic (5% vs 12% unbelted) and orthopedic (15% vs 40%) injuries (odds ratio = 3, P < .01 for both). A reproducible pattern of injury is noted for children involved in lateral-impact crashes characterized by head and chest injuries. The Injury Severity

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ambulance operations, firefighting or seasonal operations); 7 Companies proposing to provide scheduled... conduct such operations under their air taxi registration; such companies must first be found fit, willing... Region Headquarters (AAL-230), 222 West 7th Avenue, Box 14, Anchorage, Alaska 99513. ...

Occupational and Personal Determinants of Musculoskeletal Disorders among Urban Taxi Drivers in Ghana

PubMed Central

Abledu, J. K.; Offei, E. B.; Abledu, G. K.

2014-01-01

Background. There is a lack of epidemiological data on musculoskeletal disorders (MSDs) among occupational drivers in Ghana. The present study seeks to estimate the prevalence, body distribution, and occupational and personal determinants of MSDs in a sample of taxi drivers in the Accra Metropolis of Ghana. Methods. A total of 210 participants were enrolled in this cross-sectional study. All the participants were evaluated by using a semistructured questionnaire and the standardized Nordic Musculoskeletal Disorder Questionnaire. Results. The estimated prevalence of MSDs was 70.5%. The prevalence of the various MSD domains was as follows: lower back pain (34.3%), upper back pain (16.7%), neck pain (15.2%), shoulder pain (11.0%), knee pain (10.0%), hip/thigh pain (2.9%), elbow pain (4.8%), ankle/feet pain (2.4%), and wrist/hand pain (1.9%). Multiple logistic regression analysis of the data showed that participants who were employee drivers, drove taxi more than 12 hours per day or at least 5 days per week, perceived their job as stressful, and were dissatisfied with their job were at a greater risk of developing MSDs. Conclusions. These findings call for preventive strategies and safety guidelines in order to reduce the incidence of MSDs among urban taxi drivers in Ghana. PMID:27379297

Health status, job stress and work-related injury among Los Angeles taxi drivers.

PubMed

Wang, Pin-Chieh; Delp, Linda

2014-01-01

Taxi drivers work long hours for low wages and report hypertension, weight gain, and musculoskeletal pain associated with the sedentary nature of their job, stressful working conditions, and poor dietary habits. They also experience a high work-related fatality rate. The objective of this study is to examine the association of taxi drivers' health status and level of job stress with work-related injury and determine if a potential interaction exists. A survey of 309 Los Angeles taxi drivers provides basic data on health status, job stress, and work-related injuries. We further analyzed the data using a Modified Poisson regression approach with a robust error variance to estimate the relative risk (RR) and the 95% confidence intervals (CI) of work-related injuries. Focus group results supplemented and helped interpret the quantitative data. The joint effect of good health and low job stress was associated with a large reduction in the incidence of injuries, consistent with the hypothesis that health status and stress levels modify each other on the risk of work-related injury. These results suggest that the combination of stress reduction and health management programs together with changes in the stressful conditions of the job may provide targeted avenues to prevent injuries.

Occupational and Personal Determinants of Musculoskeletal Disorders among Urban Taxi Drivers in Ghana.

PubMed

Abledu, J K; Offei, E B; Abledu, G K

2014-01-01

Background. There is a lack of epidemiological data on musculoskeletal disorders (MSDs) among occupational drivers in Ghana. The present study seeks to estimate the prevalence, body distribution, and occupational and personal determinants of MSDs in a sample of taxi drivers in the Accra Metropolis of Ghana. Methods. A total of 210 participants were enrolled in this cross-sectional study. All the participants were evaluated by using a semistructured questionnaire and the standardized Nordic Musculoskeletal Disorder Questionnaire. Results. The estimated prevalence of MSDs was 70.5%. The prevalence of the various MSD domains was as follows: lower back pain (34.3%), upper back pain (16.7%), neck pain (15.2%), shoulder pain (11.0%), knee pain (10.0%), hip/thigh pain (2.9%), elbow pain (4.8%), ankle/feet pain (2.4%), and wrist/hand pain (1.9%). Multiple logistic regression analysis of the data showed that participants who were employee drivers, drove taxi more than 12 hours per day or at least 5 days per week, perceived their job as stressful, and were dissatisfied with their job were at a greater risk of developing MSDs. Conclusions. These findings call for preventive strategies and safety guidelines in order to reduce the incidence of MSDs among urban taxi drivers in Ghana.

Crash avoidance potential of four large truck technologies.

PubMed

Jermakian, Jessica S

2012-11-01

The objective of this paper was to estimate the maximum potential large truck crash reductions in the United States associated with each of four crash avoidance technologies: side view assist, forward collision warning/mitigation, lane departure warning/prevention, and vehicle stability control. Estimates accounted for limitations of current systems. Crash records were extracted from the 2004-08 files of the National Automotive Sampling System General Estimates System (NASS GES) and the Fatality Analysis Reporting System (FARS). Crash descriptors such as location of damage on the vehicle, road characteristics, time of day, and precrash maneuvers were reviewed to determine whether the information or action provided by each technology potentially could have prevented the crash. Of the four technologies, side view assist had the greatest potential for preventing large truck crashes of any severity; the technology is potentially applicable to 39,000 crashes in the United States each year, including 2000 serious and moderate injury crashes and 79 fatal crashes. Vehicle stability control is another promising technology, with the potential to prevent or mitigate up to 31,000 crashes per year including more serious crashes--up to 7000 moderate-to-serious injury crashes and 439 fatal crashes per year. Vehicle stability control could prevent or mitigate up to 20 and 11 percent of moderate-to-serious injury and fatal large truck crashes, respectively. Forward collision warning has the potential to prevent as many as 31,000 crashes per year, including 3000 serious and moderate injury crashes and 115 fatal crashes. Finally, 10,000 large truck crashes annually were relevant to lane departure warning/prevention systems. Of these, 1000 involved serious and moderate injuries and 247 involved fatal injuries. There is great potential effectiveness for truck-based crash avoidance systems. However, it is yet to be determined how drivers will interact with the systems. Actual

Not just a rural occurrence: differences in agricultural equipment crash characteristics by rural-urban crash site and proximity to town.

PubMed

Harland, Karisa K; Greenan, Mitchell; Ramirez, Marizen

2014-09-01

Although approximately one-third of agricultural equipment-related crashes occur near town, these crashes are thought to be a rural problem. This analysis examines differences between agricultural equipment-related crashes by their urban-rural distribution and distance from a town. Agricultural equipment crashes were collected from nine Midwest Departments of Transportation (2005-2008). Crash zip code was assigned as urban or rural (large, small and isolated) using Rural-Urban Commuting Areas. Crash proximity to a town was estimated with ArcGIS. Multivariable logistic regression was used to estimate the odds of crashing in an urban versus rural zip codes and across rural gradients. ANOVA analysis estimated mean distance (miles) from a crash site to a town. Over four years, 4444 crashes involved agricultural equipment. About 30% of crashes occurred in urban zip codes. Urban crashes were more likely to be non-collisions (aOR=1.69[1.24-2.30]), involve ≥2 vehicles (2 vehicles: aOR=1.58[1.14-2.20], 3+ vehicles: aOR=1.68[0.98-2.88]), occur in a town (aOR=2.06[1.73-2.45]) and within one mile of a town (aOR=1.65[1.40-1.95]) than rural crashes. The proportion of crashes within a town differed significantly across rural gradients (P<0.0001). Small rural crashes, compared to isolated rural crashes, were 1.98 (95%CI[1.28-3.06]) times more likely to be non-collisions. The distance from the crash to town differed significantly by the urban-rural distribution (P<0.0001). Crashes with agricultural equipment are unexpectedly common in urban areas and near towns and cities. Education among all roadway users, increased visibility of agricultural equipment and the development of complete rural roads are needed to increase road safety and prevent agricultural equipment-related crashes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neighborhood Influences on Vehicle-Pedestrian Crash Severity.

PubMed

Toran Pour, Alireza; Moridpour, Sara; Tay, Richard; Rajabifard, Abbas

2017-12-01

Socioeconomic factors are known to be contributing factors for vehicle-pedestrian crashes. Although several studies have examined the socioeconomic factors related to the location of the crashes, limited studies have considered the socioeconomic factors of the neighborhood where the road users live in vehicle-pedestrian crash modelling. This research aims to identify the socioeconomic factors related to both the neighborhoods where the road users live and where crashes occur that have an influence on vehicle-pedestrian crash severity. Data on vehicle-pedestrian crashes that occurred at mid-blocks in Melbourne, Australia, was analyzed. Neighborhood factors associated with road users' residents and location of crash were investigated using boosted regression tree (BRT). Furthermore, partial dependence plots were applied to illustrate the interactions between these factors. We found that socioeconomic factors accounted for 60% of the 20 top contributing factors to vehicle-pedestrian crashes. This research reveals that socioeconomic factors of the neighborhoods where the road users live and where the crashes occur are important in determining the severity of the crashes, with the former having a greater influence. Hence, road safety countermeasures, especially those focussing on the road users, should be targeted at these high-risk neighborhoods.

Occupant-to-occupant contact injury in motor vehicle crashes.

PubMed

Viano, David C; Parenteau, Chantal S

2017-10-03

This is a descriptive study of the frequency and risk of occupant-to-occupant contact injury by crash type and occupant age. It focused on rear impacts because of a recent Senate inquiry. 1994-2013 NASS-CDS data were used to investigate the effects of occupant-to-occupant contact on the risk of serious-to-fatal injury (Abbreviated Injury Scale [AIS] 3+) by crash type and age group. NASS-CDS in-depth cases were analyzed to identify crash circumstances for AIS 3+ occupant-to-occupant contact injury in rear crashes. Serious injury (AIS 3+) due to occupant-to-occupant contact was uncommon. It represented only 0.84% of all AIS 3+ injury for all age groups. The overall risk of AIS 3+ occupant-to-occupant contact injury was 0.042 ± 0.007%. The highest incidence was in side impacts (69.8%) followed by rollovers (22.9%). Occupant-to-occupant contact injury risk was lower in rear impacts than in other crash types, at 0.0078 ± 0.0054%. The highest risk of AIS 3+ injury with occupant-to-occupant was for the <9-year-old age group when compared to other age groups for all crash types. The risk was 0.051 ± 0.026%, representing 2.69% of all AIS 3+ injury in the <9-year-old age group. Only 4.2% of AIS 3+ occupant-to-occupant contact injury occurred to children <9 years old in rear impacts. The corresponding injury risk was lowest in rear impacts, at 0.014 ± 0.014%%, when compared to other crash types. The analysis of in-depth NASS-CDS cases of occupant-to-occupant contact injury in children< 9 years old involved in rear impacts identified very severe collisions in older model vehicles with deformation of the occupant compartment and yielding front seats as main factors for the contact injury. Front seat occupants injuring rear-seated children was not identified in the in-depth NASS-CDS cases. AIS 3+ occupant-to-occupant contact injury occurs primarily in side impacts and rollovers. Most contact injury is to adults (89.4% incidence). Occupant-to-occupant contact injury to

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

Validity of using linked hospital and police traffic crash records to analyse motorcycle injury crash characteristics.

PubMed

Wilson, Suzanne J; Begg, Dorothy J; Samaranayaka, Ari

2012-11-01

Linking hospital discharge and police traffic crash records has been used to provide information on causes and outcomes for hospitalised traffic crash cases. Motorcyclists are particularly vulnerable to injury in a traffic crash, but no published linkage studies have reported in detail on this road user group. The present study examined motorcycle traffic crash injury cases in New Zealand in 2000-2004 by probabilistically linking national hospital discharge records with police traffic crash reports. Injury cases had to have spent at least one night in hospital before being discharged and were defined as serious or moderate based on their International Classification of Disease Injury Severity Scores (ICISS). Despite a robust linkage process, only 46% of cases could be linked to a police record; 60% of the serious injuries and 41% of the moderate. The low linkage was most likely due to under-reporting of crashes to or by the police. While moderate injury cases were expected to be under-reported, the level of under-reporting of cases with serious threat-to-life injuries is concerning. To assess whether the linked dataset could provide valid information on the crash circumstances and injury outcomes of hospitalised motorcycle crash cases, the characteristics of the linked and unlinked hospital discharge cases were compared using chi-square tests and multivariate logistic regression. Serious injury cases were less likely to be linked if only one vehicle was involved, or the injured riders and passengers were younger than 20 years or spent less than one week in hospital. For moderate injury cases, there were also differences in linkage by injured body region and crash month. While these discrepancies need to taken into consideration when interpreting results, the linked hospital-police dataset has the potential to provide insights into motorcycle crash circumstances and outcomes not otherwise obtainable. Copyright © 2011 Elsevier Ltd. All rights reserved.

Analysis of Pedalcyclist Crashes

DOT National Transportation Integrated Search

2002-11-01

This report analyzes the problem of pedalcyclist crashes in the United States to support the development and assessment of effective pedalcyclist crash avoidance systems as part of the U.S. Department of Transportation's Intelligent Vehicle Initiativ...

Bicycling crashes on streetcar (tram) or train tracks: mixed methods to identify prevention measures.

PubMed

Teschke, Kay; Dennis, Jessica; Reynolds, Conor C O; Winters, Meghan; Harris, M Anne

2016-07-22

Streetcar or train tracks in urban areas are difficult for bicyclists to negotiate and are a cause of crashes and injuries. This study used mixed methods to identify measures to prevent such crashes, by examining track-related crashes that resulted in injuries to cyclists, and obtaining information from the local transit agency and bike shops. We compared personal, trip, and route infrastructure characteristics of 87 crashes directly involving streetcar or train tracks to 189 crashes in other circumstances in Toronto, Canada. We complemented this with engineering information about the rail systems, interviews of personnel at seven bike shops about advice they provide to customers, and width measurements of tires on commonly sold bikes. In our study, 32 % of injured cyclists had crashes that directly involved tracks. The vast majority resulted from the bike tire being caught in the rail flangeway (gap in the road surface alongside rails), often when cyclists made unplanned maneuvers to avoid a collision. Track crashes were more common on major city streets with parked cars and no bike infrastructure, with left turns at intersections, with hybrid, racing and city bikes, among less experienced and less frequent bicyclists, and among women. Commonly sold bikes typically had tire widths narrower than the smallest track flangeways. There were no track crashes in route sections where streetcars and trains had dedicated rights of way. Given our results, prevention efforts might be directed at individual knowledge, bicycle tires, or route design, but their potential for success is likely to differ. Although it may be possible to reach a broader audience with continued advice about how to avoid track crashes, the persistence and frequency of these crashes and their unpredictable circumstances indicates that other solutions are needed. Using tires wider than streetcar or train flangeways could prevent some crashes, though there are other considerations that lead many

Traffic-law enforcement and risk of death from motor-vehicle crashes: case-crossover study.

PubMed

Redelmeier, Donald A; Tibshirani, Robert J; Evans, Leonard

2003-06-28

Driving offences and traffic deaths are common in countries with high rates of motor-vehicle use. We tested whether traffic convictions, because of their direct effect on the recipient, might be associated with a reduced risk of fatal motor-vehicle crashes. We identified licensed drivers in Ontario, Canada, who had been involved in fatal crashes in the past 11 years. We used the case-crossover design to analyse the protective effect of recent convictions on individual drivers. 8975 licensed drivers had fatal crashes during the study period. 21501 driving convictions were recorded for all drivers from the date of obtaining a full licence to the date of fatal crash, equivalent to about one conviction per driver every 5 years. The risk of a fatal crash in the month after a conviction was about 35% lower than in a comparable month with no conviction for the same driver (95% CI 20-45, p=0.0002). The benefit lessened substantially by 2 months and was not significant by 3-4 months. The benefit was not altered by age, previous convictions, and other personal characteristics; was greater for speeding violations with penalty points than speeding violations without points; was no different for crashes of differing severity; and was not seen in drivers whose licences were suspended. Traffic-law enforcement effectively reduces the frequency of fatal motor-vehicle crashes in countries with high rates of motor-vehicle use. Inconsistent enforcement, therefore, may contribute to thousands of deaths each year worldwide.

Using event-triggered naturalistic data to examine the prevalence of teen driver distractions in rear-end crashes.

PubMed

Carney, Cher; Harland, Karisa K; McGehee, Daniel V

2016-06-01

While teen driver distraction is cited as a leading cause of crashes, especially rear-end crashes, little information is available regarding its true prevalence. The majority of distraction studies rely on data derived from police reports, which provide limited information regarding driver distraction. This study examined over 400 teen driver rear-end crashes captured by in-vehicle event recorders. A secondary data analysis was conducted, paying specific attention to driver behaviors, eyes-off-road time, and response times to lead-vehicle braking. Among teens in moderate to severe rear-end crashes, over 75% of drivers were observed engaging in a potentially distracting behavior. The most frequently seen driver behaviors were cell phone use, attending to a location outside the vehicle, and attending to passengers. Drivers using a cell phone had a significantly longer response time than drivers not engaged in any behaviors, while those attending to passengers did not. Additionally, in about 50% of the rear-end crashes where the driver was operating/looking at a phone (e.g., texting), the driver showed no driver response (i.e., braking or steering input) before impact, compared to 10% of crashes where the driver was attending to a passenger. The high frequency of attending to passengers and use of a cell phone leading up to a crash, compounded with the associated risks, underlines the importance of continued investigation in these areas. Parents and teens must be educated regarding the frequency of and the potential effects of distractions. Additional enforcement may be necessary if Graduated Driver Licensing (GDL) programs are to be effective. Systems that alert distracted teens could also be especially helpful in reducing rear-end collisions. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

IIHS side crash test ratings and occupant death risk in real-world crashes.

PubMed

Teoh, Eric R; Lund, Adrian K

2011-10-01

To evaluate how well the Insurance Institute for Highway Safety (IIHS) side crash test ratings predict real-world occupant death risk in side-impact crashes. The IIHS has been evaluating passenger vehicle side crashworthiness since 2003. In the IIHS side crash test, a vehicle is impacted perpendicularly on the driver's side by a moving deformable barrier simulating a typical sport utility vehicle (SUV) or pickup. Injury ratings are computed for the head/neck, torso, and pelvis/leg, and vehicles are rated based on their ability to protect occupants' heads and resist occupant compartment intrusion. Component ratings are combined into an overall rating of good, acceptable, marginal, or poor. A driver-only rating was recalculated by omitting rear passenger dummy data. Data were extracted from the Fatality Analysis Reporting System (FARS) and National Automotive Sampling System/General Estimates System (NASS/GES) for the years 2000-2009. Analyses were restricted to vehicles with driver side air bags with head and torso protection as standard features. The risk of driver death was computed as the number of drivers killed (FARS) divided by the number involved (NASS/GES) in left-side impacts and was modeled using logistic regression to control for the effects of driver age and gender and vehicle type and curb weight. Death rates per million registered vehicle years were computed for all outboard occupants and compared by overall rating. Based on the driver-only rating, drivers of vehicles rated good were 70 percent less likely to die when involved in left-side crashes than drivers of vehicles rated poor, after controlling for driver and vehicle factors. Compared with vehicles rated poor, driver death risk was 64 percent lower for vehicles rated acceptable and 49 percent lower for vehicles rated marginal. All 3 results were statistically significant. Among components, vehicle structure rating exhibited the strongest relationship with driver death risk. The vehicle

Crash avoidance potential of four passenger vehicle technologies.

PubMed

Jermakian, Jessica S

2011-05-01

The objective was to update estimates of maximum potential crash reductions in the United States associated with each of four crash avoidance technologies: side view assist, forward collision warning/mitigation, lane departure warning/prevention, and adaptive headlights. Compared with previous estimates (Farmer, 2008), estimates in this study attempted to account for known limitations of current systems. Crash records were extracted from the 2004-08 files of the National Automotive Sampling System General Estimates System (NASS GES) and the Fatality Analysis Reporting System (FARS). Crash descriptors such as vehicle damage location, road characteristics, time of day, and precrash maneuvers were reviewed to determine whether the information or action provided by each technology potentially could have prevented or mitigated the crash. Of the four crash avoidance technologies, forward collision warning/mitigation had the greatest potential for preventing crashes of any severity; the technology is potentially applicable to 1.2 million crashes in the United States each year, including 66,000 serious and moderate injury crashes and 879 fatal crashes. Lane departure warning/prevention systems appeared relevant to 179,000 crashes per year. Side view assist and adaptive headlights could prevent 395,000 and 142,000 crashes per year, respectively. Lane departure warning/prevention was relevant to the most fatal crashes, up to 7500 fatal crashes per year. A combination of all four current technologies potentially could prevent or mitigate (without double counting) up to 1,866,000 crashes each year, including 149,000 serious and moderate injury crashes and 10,238 fatal crashes. If forward collision warning were extended to detect objects, pedestrians, and bicyclists, it would be relevant to an additional 3868 unique fatal crashes. There is great potential effectiveness for vehicle-based crash avoidance systems. However, it is yet to be determined how drivers will interact with

A lightweight neighbor-info-based routing protocol for no-base-station taxi-call system.

PubMed

Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

2014-01-01

Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene.

Characteristics and contributory causes related to large truck crashes (phase II) : all crashes.

DOT National Transportation Integrated Search

2012-03-01

Statistics clearly demonstrate that large-truck crashes contribute to a significant percentage of high-severity crashes. It is : therefore important for the highway safety community to identify the characteristics and contributory causes of these typ...

Comparing international crash statistics

DOT National Transportation Integrated Search

1999-12-01

In order to examine national developments in traffic safety, crash statistics from several of the more safety, crash statistics from several of the more United States. Data obtained from the Fatality Analysis Reporting System (FARS) and the Internati...

Crash rates at intersections.

DOT National Transportation Integrated Search

2003-08-01

The objective of this study were to develop a database of intersections, match traffic crashes to these intersections, calculate rates for intersections, and identify intersections with the highest crash rates. A procedure was used to: a) identify in...

Illinois crash facts and statistics, 2002

DOT National Transportation Integrated Search

2002-01-01

This publication, Illinois Traffic Crash Facts : and Statistics for 2002, is designed to provide an : overview of motor vehicle crash experience in : Illinois. In addition to a plethora of crash data, the : publication includes key events in th...

Illinois crash facts and statistics, 2001

DOT National Transportation Integrated Search

2001-01-01

This publication, Illinois Traffic Crash Facts : and Statistics for 2001, is designed to provide an : overview of motor vehicle crash experience in : Illinois. In addition to a plethora of crash data, the : publication includes key events in th...

Illinois crash facts and statistics, 2003

DOT National Transportation Integrated Search

2003-01-01

This publication, Illinois Traffic Crash Facts : and Statistics for 2003, is designed to provide an : overview of motor vehicle crash experience in : Illinois. In addition to a plethora of crash data, the : publication includes key events in th...

Modal analysis of the human neck in vivo as a criterion for crash test dummy evaluation

NASA Astrophysics Data System (ADS)

Willinger, R.; Bourdet, N.; Fischer, R.; Le Gall, F.

2005-10-01

Low speed rear impact remains an acute automative safety problem because of a lack of knowledge of the mechanical behaviour of the human neck early after impact. Poorly validated mathematical models of the human neck or crash test dummy necks make it difficult to optimize automotive seats and head rests. In this study we have constructed an experimental and theoretical modal analysis of the human head-neck system in the sagittal plane. The method has allowed us to identify the mechanical properties of the neck and to validate a mathematical model in the frequency domain. The extracted modal characteristics consist of a first natural frequency at 1.3±0.1 Hz associated with head flexion-extension motion and a second mode at 8±0.7 Hz associated with antero-posterior translation of the head, also called retraction motion. Based on this new validation parameters we have been able to compare the human and crash test dummy frequency response functions and to evaluate their biofidelity. Three head-neck systems of current test dummies dedicated for use in rear-end car crash accident investigations have been evaluated in the frequency domain. We did not consider any to be acceptable, either because of excessive rigidity of their flexion-extension mode or because they poorly reproduce the head translation mode. In addition to dummy evaluation, this study provides new insight into injury mechanisms when a given natural frequency can be linked to a specific neck deformation.

Sleep-related vehicle crashes on low speed roads.

PubMed

Filtness, A J; Armstrong, K A; Watson, A; Smith, S S

2017-02-01

Very little is known about the characteristics of sleep related (SR) crashes occurring on low speed roads compared with current understanding of the role of sleep in crashes occurring on high speed roads e.g. motorways. To address this gap, analyses were undertaken to identify the differences and similarities between (1) SR crashes occurring on roads with low (≤60km/h) and high (≥100km/h) speed limits, and (2) SR crashes and not-SR crashes occurring on roads with low speed limits. Police reports of all crashes occurring on low and high speed roads over a ten year period between 2000 and 2009 were examined for Queensland, Australia. Attending police officers identified all crash attributes, including 'fatigue/fell asleep', which indicates that the police believe the crash to have a causal factor relating to falling asleep, sleepiness due to sleep loss, time of day, or fatigue. Driver or rider involvement in crashes was classified as SR or not-SR. All crash-associated variables were compared using Chi-square tests (Cramer's V=effect size). A series of logistic regression was performed, with driver and crash characteristics as predictors of crash category. A conservative alpha level of 0.001 determined statistical significance. There were 440,855 drivers or riders involved in a crash during this time; 6923 (1.6%) were attributed as SR. SR crashes on low speed roads have similar characteristics to those on high speed roads with young (16-24y) males consistently over represented. SR crashes on low speed roads are noticeably different to not-SR crashes in the same speed zone in that male and young novice drivers are over represented and outcomes are more severe. Of all the SR crashes identified, 41% occurred on low speed roads. SR crashes are not confined to high speed roads. Low speed SR crashes warrant specific investigation because they occur in densely populated areas, exposing a greater number of people to risk and have more severe outcomes than not-SR crashes

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.

Crash cost estimates by maximum police-reported injury severity within selected crash geometrics

DOT National Transportation Integrated Search

2005-10-01

This paper presents estimates for the economic (human capital) and comprehensive costs per crash for six KABCO groupings within 22 selected crash types and within two speed limit categories (=80 km/h (>= 50 mi/h)). The comp...

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

Comparison of crash rates and rear-end striking crashes among novice teens and experienced adults using the SHRP2 Naturalistic Driving Study.

PubMed

Seacrist, Thomas; Belwadi, Aditya; Prabahar, Abhiti; Chamberlain, Samuel; Megariotis, James; Loeb, Helen

2016-09-01

Motor vehicle crashes are the leading cause of death for teens. Previous teen and adult crash rates have been based upon fatal crashes, police-reported crashes, and estimated miles driven. Large-scale naturalistic driving studies offer the opportunity to compute crash rates using a reliable methodology to capture crashes and driving exposure. The Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study contains extensive real-world data on teen and adult driving. This article presents findings on the crash rates of novice teen and experienced adult drivers in naturalistic crashes. A subset from the SHRP2 database consisting of 539 crash events for novice teens (16-19 years, n = 549) and experienced adults (35-54 years, n = 591) was used. Onboard instrumentation such as scene cameras, accelerometers, and Global Positioning System logged time series data at 10 Hz. Scene videos were reviewed for all events to identify rear-end striking crashes. Dynamic variables such as acceleration and velocity were analyzed for rear-end striking events. Number of crashes, crash rates, rear-end striking crash severity, and rear-end striking impact velocity were compared between novice teens and experienced adults. Video review of the SHRP2 crashes identified significantly more crashes (P < 0.01) and rear-end striking crashes (P < 0.01) among the teen group than among the adult group. This yielded crash rates of 30.0 crashes per million miles driven for novice teens compared to 5.3 crashes per million miles driven for experienced adults. The crash rate ratio for teens vs. adults was 5.7. The rear-end striking crash rate was 13.5 and 1.8 per million miles driven for novice teens and experienced adults, respectively. The rear-end striking crash rate ratio for teens vs. adults was 7.5. The rear-end striking crash severity measured by the accelerometers was greater (P < 0.05) for the teen group (1.8 ± 0.9 g; median = 1.6 g) than for the adult group (1.1 ± 0.4 g

1997 New Mexico traffic crash information

DOT National Transportation Integrated Search

1998-06-01

This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1997. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

1995 New Mexico traffic crash information

DOT National Transportation Integrated Search

1996-09-01

This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1995. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

2000 New Mexico traffic crash information

DOT National Transportation Integrated Search

2002-03-01

This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2000. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

2005 New Mexico traffic crash information

DOT National Transportation Integrated Search

2006-11-01

This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2005. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

2001 New Mexico traffic crash information

DOT National Transportation Integrated Search

2003-01-01

This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2001. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

2008 New Mexico traffic crash information

DOT National Transportation Integrated Search

2010-05-01

This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through December, : 2008. It presents crash data in the form of graphs for those who : prefer an impressionistic view and tables for those wh...

1996 New Mexico traffic crash information

DOT National Transportation Integrated Search

1997-06-01

This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1997. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

1998 New Mexico traffic crash information

DOT National Transportation Integrated Search

1999-06-01

This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1998. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

2002 New Mexico traffic crash information

DOT National Transportation Integrated Search

2004-02-01

This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2002. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

Highway crash site management

DOT National Transportation Integrated Search

2003-07-01

Traveler delay is the problem most often associated with highway crashes, but by far the most serious problem is the resulting secondary crashes that occur. Another related issue is the danger posed to response personnel serving the public at the sce...

Indiana crash facts 2000

DOT National Transportation Integrated Search

2000-01-01

The 2000 Crash Facts, a compilation of the approximately 220,000 : crashes that occurred throughout the state of Indiana. The year 2000 established a number of : record-setting lows in the area of traffic safety for our state. Specifically, fatal cra...

Red-Light-Running Crashes' Classification, Comparison, and Risk Analysis Based on General Estimates System (GES) Crash Database.

PubMed

Zhang, Yuting; Yan, Xuedong; Li, Xiaomeng; Wu, Jiawei; Dixit, Vinayak V

2018-06-19

Red-light running (RLR) has been identified as one of the prominent contributing factors involved in signalized intersection crashes. In order to reduce RLR crashes, primarily, a better understanding of RLR behavior and crashes is needed. In this study, three RLR crash types were extracted from the general estimates system (GES), including go-straight (GS) RLR vehicle colliding with go-straight non-RLR vehicle, go-straight RLR vehicle colliding with left-turn (LT) non-RLR vehicle, and left-turn RLR vehicle colliding with go-straight non-RLR vehicle. Then, crash features within each crash type scenario were compared, and risk analyses of GS RLR and LT RLR were also conducted. The results indicated that for the GS RLR driver, the speed limit displayed the highest effects on the percentages of GS RLR collision scenarios. For the LT RLR driver, the number of lanes displayed the highest effects on the percentages of LT RLR collision scenarios. Additionally, the drivers who were older than 50 years, distracted, and had a limited view were more likely to be involved in LT RLR accidents. Furthermore, the speeding drivers were more likely to be involved in GS RLR accidents. These findings could give a comprehensive understanding of RLR crash features and propensities for each RLR crash type.

Development of test scenarios for off-roadway crash countermeasures based on crash statistics

DOT National Transportation Integrated Search

2002-09-01

This report presents the results from an analysis of off-roadway crashes and proposes a set of crash-imminent scenarios to objectively test countermeasure systems for light vehicles (passenger cars, sport utility vehicles, vans, and pickup trucks) ba...

2009 New Mexico traffic crash information

DOT National Transportation Integrated Search

2011-05-01

This edition of New Mexico Traffic Crash Information reviews traffic crash data in New Mexico from January through December, 2009. It presents crash data in the form of graphs for those who prefer an impressionistic view and tables for those who requ...

1999 New Mexico traffic crash information

DOT National Transportation Integrated Search

2001-03-01

This edition of New Mexico Traffic Crash Information reviews traffic crash data in New MExico from January through Decemeber, 1999. It presents crash data in the form of graphs for those who prefer an impressionistic view and tables for those who req...

Illinois crash facts and statistics, 2010

DOT National Transportation Integrated Search

2011-01-01

The number of reported motor vehicle crashes decreased from the previous year to fewer than 290,000 crashes in calendar year 2010. In addition, the number of persons injured in crashes dropped below 89,000 and the number of fatalities on Illinois roa...

2006 New Mexico traffic crash information

DOT National Transportation Integrated Search

2007-10-01

This edition of New Mexico Traffi c Crash Information : reviews traffi c crash data in New Mexico from January : through December, 2006. It presents crash data in the : form of graphs for those who prefer an impressionistic view : and tables for thos...

2007 New Mexico traffic crash information

DOT National Transportation Integrated Search

2009-12-01

This edition of New Mexico Traffi c Crash Information reviews : traffi c crash data in New Mexico from January through December, : 2007. It presents crash data in the form of graphs for those who : prefer an impressionistic view and tables for those ...

Costs of Alcohol-Involved Crashes, United States, 2010

PubMed Central

Zaloshnja, Eduard; Miller, Ted R.; Blincoe, Lawrence J.

2013-01-01

This paper estimates total and unit costs of alcohol-involved crashes in the U.S. in 2010. With methods from earlier studies, we estimated costs per crash survivor by MAIS, body part, and fracture/dislocation involvement. We multiplied them times 2010 crash incidence estimates from NHTSA data sets, with adjustments for underreporting of crashes and their alcohol involvement. The unit costs are lifetime costs discounted at 3%. To develop medical costs, we combined 2008 Health Care Utilization Program national data for hospitalizations and ED visits of crash survivors with prior estimates of post-discharge costs. Productivity losses drew on Current Population Survey and American Time Use Survey data. Quality of life losses came from a 2011 AAAM paper and property damage from insurance data. We built a hybrid incidence file comprised of 2008–2010 and 1984–86 NHTSA crash surveillance data, weighted with 2010 General Estimates System weights. Fatality data came from the 2010 FARS. An estimated 12% of 2010 crashes but only 0.9% of miles driven were alcohol-involved (BAC > .05). Alcohol-involved crashes cost an estimated $125 billion. That is 22.5% of the societal cost of all crashes. Alcohol-attributable crashes accounted for an estimated 22.5% of US auto liability insurance payments. Alcohol-involved crashes cost $0.86 per drink. Above the US BAC limit of .08, crash costs were $8.37 per mile driven; 1 in 788 trips resulted in a crash and 1 in 1,016 trips in an arrest. Unit costs for crash survivors by severity are higher for impaired driving than for other crashes. That suggests national aggregate impaired driving cost estimates in other countries are substantial underestimates if they are based on all-crash unit costs. PMID:24406941

Underreporting, crash severity and fault assignment of minor crashes in China - a study based on self-reported surveys.

PubMed

Yang, Hongtai; Cherry, Christopher R; Su, Fan; Ling, Ziwen; Pannell, Zane; Li, Yanlai; Fu, Zhijian

2018-05-25

Unreported minor crashes have importance as a surrogate for more serious crashes that require infrastructure, education, and enforcement strategies; and they still inflict damages. To study factors that influence underreporting, cause, and severity of minor crashes; a survey was performed in Kunming and Beijing to collect self-reported personal characteristics and crash history data of the three major urban road users in China: automobile drivers, bicycle riders and electric bike (e-bike) riders. Underreporting rates of automobile to automobile, automobile to non-motorized vehicle, and non-motorized vehicle to non-motorized vehicle crashes are 56%, 77% and 94%, respectively. Minor crashes with higher reported injury severity levels are more likely to be reported. E-bike riders without a driver's license are more likely to cause crashes. Licensing and education could be an effective way to reduce their crashes. The party that is not at fault in a crash is more likely to sustain high level of injury.

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 energy...

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 energy...

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 energy...

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 energy...

Effect of electronic stability control on automobile crash risk.

PubMed

Farmer, Charles

2004-12-01

Per vehicle crash involvement rates were compared for otherwise identical vehicle models with and without electronic stability control (ESC) systems. ESC was found to affect single-vehicle crashes to a greater extent than multiple-vehicle crashes, and crashes with fatal injuries to a greater extent than less severe crashes. Based on all police-reported crashes in 7 states over 2 years, ESC reduced single-vehicle crash involvement risk by approximately 41 percent (95 percent confidence limits 3348) and single-vehicle injury crash involvement risk by 41 percent (2752). This translates to an estimated 7 percent reduction in overall crash involvement risk (310) and a 9 percent reduction in overall injury crash involvement risk (314). Based on all fatal crashes in the United States over 3 years, ESC was found to have reduced single-vehicle fatal crash involvement risk by 56 percent (3968). This translates to an estimated 34 percent reduction in overall fatal crash involvement risk (2145).

Effects of enforcement intensity on alcohol impaired driving crashes.

PubMed

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

2014-12-01

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. 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. 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 22-26 communities with complete data. Log-linear regressions were used throughout the study. 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 drivers on the roads surveyed in the

Indiana crash facts 1999

DOT National Transportation Integrated Search

1997-01-01

The 892 fatal crashes in 1999 resulted in 1,021 fatalities. : This equates to a fatality each and every 8 hours : during 1999. The number of fatalities and fatal crashes : represented one of the worst years in the past decade for : Indiana. The 72,...

Macro-level safety analysis of pedestrian crashes in Shanghai, China.

PubMed

Wang, Xuesong; Yang, Junguang; Lee, Chris; Ji, Zhuoran; You, Shikai

2016-11-01

Pedestrian safety has become one of the most important issues in the field of traffic safety. This study aims at investigating the association between pedestrian crash frequency and various predictor variables including roadway, socio-economic, and land-use features. The relationships were modeled using the data from 263 Traffic Analysis Zones (TAZs) within the urban area of Shanghai - the largest city in China. Since spatial correlation exists among the zonal-level data, Bayesian Conditional Autoregressive (CAR) models with seven different spatial weight features (i.e. (a) 0-1 first order, adjacency-based, (b) common boundary-length-based, (c) geometric centroid-distance-based, (d) crash-weighted centroid-distance-based, (e) land use type, adjacency-based, (f) land use intensity, adjacency-based, and (g) geometric centroid-distance-order) were developed to characterize the spatial correlations among TAZs. Model results indicated that the geometric centroid-distance-order spatial weight feature, which was introduced in macro-level safety analysis for the first time, outperformed all the other spatial weight features. Population was used as the surrogate for pedestrian exposure, and had a positive effect on pedestrian crashes. Other significant factors included length of major arterials, length of minor arterials, road density, average intersection spacing, percentage of 3-legged intersections, and area of TAZ. Pedestrian crashes were higher in TAZs with medium land use intensity than in TAZs with low and high land use intensity. Thus, higher priority should be given to TAZs with medium land use intensity to improve pedestrian safety. Overall, these findings can help transportation planners and managers understand the characteristics of pedestrian crashes and improve pedestrian safety. Copyright © 2016 Elsevier Ltd. All rights reserved.

Side Impact Regulatory Trends, Crash Environment and Injury Risk in the USA.

PubMed

Prasad, Priya; Dalmotas, Dainius; Chouinard, Aline

2015-11-01

Light duty vehicles in the US are designed to meet and exceed regulatory standards, self-imposed industry agreements and safety rating tests conducted by NHTSA and IIHS. The evolution of side impact regulation in the US from 1973 to 2015 is discussed in the paper along with two key industry agreements in 2003 affecting design of restraint systems and structures for side impact protection. A combination of all the above influences shows that vehicles in the US are being designed to more demanding and comprehensive requirements than in any other region of the world. The crash environment in the US related to side impacts was defined based on data in the nationally representative crash database NASS. Crash environment factors, including the distribution of cars, light trucks and vans (LTV's), and medium-to-heavy vehicles (MHV's) in the fleet, and the frequency of their interactions with one another in side impacts, were considered. Other factors like, crash severity in terms of closing velocity between two vehicles involved in crash, gender and age of involved drivers in two-vehicle and single vehicle crashes, were also examined. Injury risks in side impacts to drivers and passengers were determined in various circumstances such as near-side, far-side, and single vehicle crashes as a function of crash severity, in terms of estimated closing speed or lateral delta-V. Also injury risks in different pairs of striking and struck cars and LTV's, were estimated. A logistic regression model for studying injury risks in two vehicle crashes was developed. The risk factors included in the model include case and striking vehicles, consisting of cars, SUV's, vans, and pickup trucks, delta-V, damage extent, occupant proximity to the impact side, age and gender of the occupant, and belt use. Results show that car occupants make up the vast majority of serious-to-fatally injured occupants. Injury rates of car occupants in two-vehicle collision are highest when the car is struck by a

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

Crash Position Indicator/Crash Survivable Flight Data Recorder Ejectable versus Nonejectable

DTIC Science & Technology

1983-07-27

for environmental protection. The radio beacon transmitter, antenna, and manual shutoff switch are molded into the airfoil foam. The battery and CSFDR...FWD BATERY LRADIO) BEACON ANTENNA TRANSMITTER SOLID-STATE FLIGHT INCIDENT RECORDER Figure 2 DEPLOYABLE FLIGHT INCIDENT RECORDER/CRASH POSITION LOCATOR...mechanical and thermal environment than do ejectable systems that depart the aircraft and clear the crash and fire. As a result of the more stringent

A logistic model of the effects of roadway, environmental, vehicle, crash and driver characteristics on hit-and-run crashes.

PubMed

Tay, Richard; Rifaat, Shakil Mohammad; Chin, Hoong Chor

2008-07-01

Leaving the scene of a crash without reporting it is an offence in most countries and many studies have been devoted to improving ways to identify hit-and-run vehicles and the drivers involved. However, relatively few studies have been conducted on identifying factors that contribute to the decision to run after the crash. This study identifies the factors that are associated with the likelihood of hit-and-run crashes including driver characteristics, vehicle types, crash characteristics, roadway features and environmental characteristics. Using a logistic regression model to delineate hit-and-run crashes from nonhit-and-run crashes, this study found that drivers were more likely to run when crashes occurred at night, on a bridge and flyover, bend, straight road and near shop houses; involved two vehicles, two-wheel vehicles and vehicles from neighboring countries; and when the driver was a male, minority, and aged between 45 and 69. On the other hand, collisions involving right turn and U-turn maneuvers, and occurring on undivided roads were less likely to be hit-and-run crashes.

1999 Iowa crash facts : a summary of motor vehicle crash statistics on Iowa roadways

DOT National Transportation Integrated Search

1999-01-01

All information concerning Iowa traffic crashes was taken from report forms : provided by investigating officers and drivers involved in crashes. : All statistics are gathered and calculated by the Iowa Department of Transportations Office of Driv...

Pre-crash scenario framework for crash avoidance systems based on vehicle-to-vehicle communications

DOT National Transportation Integrated Search

2011-06-13

This paper prioritizes and statistically describes precrash : scenarios as a basis for the identification of : crash avoidance functions enhanced or enabled by : vehicle-to-vehicle (V2V) communication technology. : Pre-crash scenarios depict vehicle ...

1997 Iowa crash summary : a summary of motor vehicle crash statistics on Iowa roadways

DOT National Transportation Integrated Search

1997-01-01

All information concerning Iowa : traffic crashes was taken from report forms provided by investigating officers and drivers involved in : crashes. : All statistics are gathered and calculated by the Iowa Department of Transportations Office of Dr...

1996 Iowa crash summary : a summary of motor vehicle crash statistics on Iowa roadways

DOT National Transportation Integrated Search

1996-01-01

All information concerning Iowa : traffic crashes was taken from report forms provided by investigating officers and drivers involved in : crashes. : All statistics are gathered and calculated by the Iowa Department of Transportations Office of Dr...

1998 Iowa crash summary : a summary of motor vehicle crash statistics on Iowa roadways

DOT National Transportation Integrated Search

1998-01-01

All information concerning Iowa : traffic crashes was taken from report forms provided by investigating officers and drivers involved in : crashes. : All statistics are gathered and calculated by the Iowa Department of Transportations Office of Dr...

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

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

PubMed

Subaiya, Saleena; Hogg, Euan; Roberts, Ian

2011-02-03

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. 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. 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). 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. CRASH-1: ISRCTN74459797CRASH-2: ISRCTN86750102.

Robust human body model injury prediction in simulated side impact crashes.

PubMed

Golman, Adam J; Danelson, Kerry A; Stitzel, Joel D

2016-01-01

This study developed a parametric methodology to robustly predict occupant injuries sustained in real-world crashes using a finite element (FE) human body model (HBM). One hundred and twenty near-side impact motor vehicle crashes were simulated over a range of parameters using a Toyota RAV4 (bullet vehicle), Ford Taurus (struck vehicle) FE models and a validated human body model (HBM) Total HUman Model for Safety (THUMS). Three bullet vehicle crash parameters (speed, location and angle) and two occupant parameters (seat position and age) were varied using a Latin hypercube design of Experiments. Four injury metrics (head injury criterion, half deflection, thoracic trauma index and pelvic force) were used to calculate injury risk. Rib fracture prediction and lung strain metrics were also analysed. As hypothesized, bullet speed had the greatest effect on each injury measure. Injury risk was reduced when bullet location was further from the B-pillar or when the bullet angle was more oblique. Age had strong correlation to rib fractures frequency and lung strain severity. The injuries from a real-world crash were predicted using two different methods by (1) subsampling the injury predictors from the 12 best crush profile matching simulations and (2) using regression models. Both injury prediction methods successfully predicted the case occupant's low risk for pelvic injury, high risk for thoracic injury, rib fractures and high lung strains with tight confidence intervals. This parametric methodology was successfully used to explore crash parameter interactions and to robustly predict real-world injuries.

Macro-level pedestrian and bicycle crash analysis: Incorporating spatial spillover effects in dual state count models.

PubMed

Cai, Qing; Lee, Jaeyoung; Eluru, Naveen; Abdel-Aty, Mohamed

2016-08-01

This study attempts to explore the viability of dual-state models (i.e., zero-inflated and hurdle models) for traffic analysis zones (TAZs) based pedestrian and bicycle crash frequency analysis. Additionally, spatial spillover effects are explored in the models by employing exogenous variables from neighboring zones. The dual-state models such as zero-inflated negative binomial and hurdle negative binomial models (with and without spatial effects) are compared with the conventional single-state model (i.e., negative binomial). The model comparison for pedestrian and bicycle crashes revealed that the models that considered observed spatial effects perform better than the models that did not consider the observed spatial effects. Across the models with spatial spillover effects, the dual-state models especially zero-inflated negative binomial model offered better performance compared to single-state models. Moreover, the model results clearly highlighted the importance of various traffic, roadway, and sociodemographic characteristics of the TAZ as well as neighboring TAZs on pedestrian and bicycle crash frequency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Small City Transit : El Cajon, California : City-Wide Shared-Ride Taxi Service

DOT National Transportation Integrated Search

1976-03-01

El Cajon, California, is an illustration of a shared ride taxi service. This case study is one of thirteen examples of a transit service in a small community. The background of the community is discussed along with a description of the implementation...

Gasoline prices and their relationship to drunk-driving crashes.

PubMed

Chi, Guangqing; Zhou, Xuan; McClure, Timothy E; Gilbert, Paul A; Cosby, Arthur G; Zhang, Li; Robertson, Angela A; Levinson, David

2011-01-01

This study investigates the relationship between changing gasoline prices and drunk-driving crashes. Specifically, we examine the effects of gasoline prices on drunk-driving crashes in Mississippi by several crash types and demographic groups at the monthly level from 2004 to 2008, a period experiencing great fluctuation in gasoline prices. An exploratory visualization by graphs shows that higher gasoline prices are generally associated with fewer drunk-driving crashes. Higher gasoline prices depress drunk-driving crashes among young and adult drivers, among male and female drivers, and among white and black drivers. Results from negative binomial regression models show that when gas prices are higher, there are fewer drunk-driving crashes, particularly among property-damage-only crashes. When alcohol consumption levels are higher, there are more drunk-driving crashes, particularly fatal and injury crashes. The effects of gasoline prices and alcohol consumption are stronger on drunk-driving crashes than on all crashes. The findings do not vary much across different demographic groups. Overall, gasoline prices have greater effects on less severe crashes and alcohol consumption has greater effects on more severe crashes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Understanding traffic crash under-reporting: Linking police and medical records to individual and crash characteristics.

PubMed

Janstrup, Kira H; Kaplan, Sigal; Hels, Tove; Lauritsen, Jens; Prato, Carlo G

2016-08-17

This study aligns to the body of research dedicated to estimating the underreporting of road crash injuries and adds the perspective of understanding individual and crash factors contributing to the decision to report a crash to the police, the hospital, or both. This study focuses on road crash injuries that occurred in the province of Funen, Denmark, between 2003 and 2007 and were registered in the police, the hospital, or both authorities. Underreporting rates are computed with the capture-recapture method, and the probability for road crash injuries in police records to appear in hospital records (and vice versa) is estimated with joint binary logit models. The capture-recapture analysis shows high underreporting rates of road crash injuries in Denmark and the growth of underreporting not only with the decrease in injury severity but also with the involvement of cyclists (reporting rates of about 14% for serious injuries and 7% for slight injuries) and motorcyclists (reporting rates of about 35% for serious injuries and 10% for slight injuries). Model estimates show that the likelihood of appearing in both data sets is positively related to helmet and seat belt use, number of motor vehicles involved, alcohol involvement, higher speed limit, and females being injured. This study adds significantly to the literature about underreporting by recognizing that understanding the heterogeneity in the reporting rate of road crashes may lead to devising policy measures aimed at increasing the reporting rate by targeting specific road user groups (e.g., males, young road users) or specific situational factors (e.g., slight injuries, arm injuries, leg injuries, weekend).

An efficient parallel sampling technique for Multivariate Poisson-Lognormal model: Analysis with two crash count datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhan, Xianyuan; Aziz, H. M. Abdul; Ukkusuri, Satish V.

Our study investigates the Multivariate Poisson-lognormal (MVPLN) model that jointly models crash frequency and severity accounting for correlations. The ordinary univariate count models analyze crashes of different severity level separately ignoring the correlations among severity levels. The MVPLN model is capable to incorporate the general correlation structure and takes account of the over dispersion in the data that leads to a superior data fitting. But, the traditional estimation approach for MVPLN model is computationally expensive, which often limits the use of MVPLN model in practice. In this work, a parallel sampling scheme is introduced to improve the original Markov Chainmore » Monte Carlo (MCMC) estimation approach of the MVPLN model, which significantly reduces the model estimation time. Two MVPLN models are developed using the pedestrian vehicle crash data collected in New York City from 2002 to 2006, and the highway-injury data from Washington State (5-year data from 1990 to 1994) The Deviance Information Criteria (DIC) is used to evaluate the model fitting. The estimation results show that the MVPLN models provide a superior fit over univariate Poisson-lognormal (PLN), univariate Poisson, and Negative Binomial models. Moreover, the correlations among the latent effects of different severity levels are found significant in both datasets that justifies the importance of jointly modeling crash frequency and severity accounting for correlations.« less

An efficient parallel sampling technique for Multivariate Poisson-Lognormal model: Analysis with two crash count datasets

DOE PAGES

Zhan, Xianyuan; Aziz, H. M. Abdul; Ukkusuri, Satish V.

2015-11-19

Our study investigates the Multivariate Poisson-lognormal (MVPLN) model that jointly models crash frequency and severity accounting for correlations. The ordinary univariate count models analyze crashes of different severity level separately ignoring the correlations among severity levels. The MVPLN model is capable to incorporate the general correlation structure and takes account of the over dispersion in the data that leads to a superior data fitting. But, the traditional estimation approach for MVPLN model is computationally expensive, which often limits the use of MVPLN model in practice. In this work, a parallel sampling scheme is introduced to improve the original Markov Chainmore » Monte Carlo (MCMC) estimation approach of the MVPLN model, which significantly reduces the model estimation time. Two MVPLN models are developed using the pedestrian vehicle crash data collected in New York City from 2002 to 2006, and the highway-injury data from Washington State (5-year data from 1990 to 1994) The Deviance Information Criteria (DIC) is used to evaluate the model fitting. The estimation results show that the MVPLN models provide a superior fit over univariate Poisson-lognormal (PLN), univariate Poisson, and Negative Binomial models. Moreover, the correlations among the latent effects of different severity levels are found significant in both datasets that justifies the importance of jointly modeling crash frequency and severity accounting for correlations.« less

Impact Landing Dynamics Facility Crash Test

NASA Image and Video Library

1975-08-03

Photographed on: 08/03/75. -- By 1972 the Lunar Landing Research Facility was no longer in use for its original purpose. The 400-foot high structure was swiftly modified to allow engineers to study the dynamics of aircraft crashes. "The Impact Dynamics Research Facility is used to conduct crash testing of full-scale aircraft under controlled conditions. The aircraft are swung by cables from an A-frame structure that is approximately 400 ft. long and 230 foot high. The impact runway can be modified to simulate other grand crash environments, such as packed dirt, to meet a specific test requirement." "In 1972, NASA and the FAA embarked on a cooperative effort to develop technology for improved crashworthiness and passenger survivability in general aviation aircraft with little or no increase in weight and acceptable cost. Since then, NASA has "crashed" dozens of GA aircraft by using the lunar excursion module (LEM) facility originally built for the Apollo program." This photograph shows Crash Test No. 7. Crash Test: Test #7

Using medico-legal data to investigate fatal older road user crash circumstances and risk factors.

PubMed

Koppel, Sjaan; Bugeja, Lyndal; Smith, Daisy; Lamb, Ashne; Dwyer, Jeremy; Fitzharris, Michael; Newstead, Stuart; D'Elia, Angelo; Charlton, Judith

2018-02-17

This study used medico-legal data to investigate fatal older road user (ORU, aged 65 years and older) crash circumstances and risk factors relating to 4 key components of the Safe System approach (e.g., roads and roadsides, vehicles, road users, and speeds) to identify areas of priority for targeted prevention activity. The Coroners' Court of Victoria's (CCOV) Surveillance Database was searched to identify and describe the frequency and rate per 100,000 population of fatal ORU crashes in the Australian state of Victoria for 2013-2014. Information relating to the deceased ORU, crash characteristics and circumstances, and risk factors was extracted and analyzed. One hundred and thirty-eight unintentional fatal ORU crashes were identified in the CCOV Surveillance Database. Of these fatal ORU crashes, most involved older drivers (44%), followed by older pedestrians (32%), older passengers (17%), older pedal cyclists (4%), older motorcyclists (1%), and older mobility scooter users (1%). The average annual rate of fatal ORU crashes per 100,000 population was 8.1 (95% confidence interval [CI], 6.0-10.2). In terms of the crash characteristics and circumstances, most fatal ORU crashes involved a counterpart (98%), of which the majority were passenger cars (50%) or fixed/stationary objects (25%), including trees (46%) or embankments (23%). In addition, most fatal ORU crashes occurred close to home (73%), on-road (87%), on roads that were paved (94%), on roads with light traffic volume (37%), and during low-risk conditions: between 12 p.m. and 6 p.m. (44%), on weekdays (80%), during daylight (75%), and under dry/clear conditions (81%). Road user (RU) error was identified by the police and/or the coroner for the majority of fatal crashes (55%), with a significant proportion of deceased ORUs deemed to have failed to yield (54%) or misjudged (41%). RU error was the most significant factor identified in fatal ORU crashes, which suggests that there is a limited capacity of the

Training and Proficiency Testing for Commuter and Air Taxi Pilots - Federal Aviation Administration

DOT National Transportation Integrated Search

1996-10-21

The objective of this audit was to determine whether the Federal Aviation : Administration (FAA) has established procedures and oversight controls to assure : that commuter and air taxi pilots, engaged in passenger-carrying operations, : hold valid p...

Potential for Flexicab Services : Innovative Uses of Taxis and Jitneys for Public Transportation

DOT National Transportation Integrated Search

1975-12-01

Taxis and jitneys can be significant urban transportation resource. Used innovatively to provide public transit services, they can offer mobility in low density areas where mass transit is not feasible, supplement mass transit economically to improve...

Crashes and near-crashes on horizontal curves along rural two-lane highways: Analysis of naturalistic driving data.

PubMed

Wang, Bo; Hallmark, Shauna; Savolainen, Peter; Dong, Jing

2017-12-01

Prior research has shown the probability of a crash occurring on horizontal curves to be significantly higher than on similar tangent segments, and a disproportionally higher number of curve-related crashes occurred in rural areas. Challenges arise when analyzing the safety of horizontal curves due to imprecision in integrating information as to the temporal and spatial characteristics of each crash with specific curves. The second Strategic Highway Research Program(SHRP 2) conducted a large-scale naturalistic driving study (NDS),which provides a unique opportunity to better understand the contributing factors leading to crash or near-crash events. This study utilizes high-resolution behavioral data from the NDS to identify factors associated with 108 safety critical events (i.e., crashes or near-crashes) on rural two-lane curves. A case-control approach is utilized wherein these events are compared to 216 normal, baseline-driving events. The variables examined in this study include driver demographic characteristics, details of the traffic environment and roadway geometry, as well as driver behaviors such as in-vehicle distractions. Logistic regression models are estimated to discern those factors affecting the likelihood of a driver being crash-involved. These factors include high-risk behaviors, such as speeding and visual distractions, as well as curve design elements and other roadway characteristics such as pavement surface conditions. This paper successfully integrated driver behavior, vehicle characteristics, and roadway environments into the same model. Logistic regression model was found to be an effective way to investigate crash risks using naturalistic driving data. This paper revealed a number of contributing factors to crashes on rural two-lane curves, which has important implications in traffic safety policy and curve geometry design. This paper also discussed limitations and lessons learned from working with the SHRP 2 NDS data. It will benefit

A crash-prediction model for multilane roads.

PubMed

Caliendo, Ciro; Guida, Maurizio; Parisi, Alessandra

2007-07-01

Considerable research has been carried out in recent years to establish relationships between crashes and traffic flow, geometric infrastructure characteristics and environmental factors for two-lane rural roads. Crash-prediction models focused on multilane rural roads, however, have rarely been investigated. In addition, most research has paid but little attention to the safety effects of variables such as stopping sight distance and pavement surface characteristics. Moreover, the statistical approaches have generally included Poisson and Negative Binomial regression models, whilst Negative Multinomial regression model has been used to a lesser extent. Finally, as far as the authors are aware, prediction models involving all the above-mentioned factors have still not been developed in Italy for multilane roads, such as motorways. Thus, in this paper crash-prediction models for a four-lane median-divided Italian motorway were set up on the basis of accident data observed during a 5-year monitoring period extending between 1999 and 2003. The Poisson, Negative Binomial and Negative Multinomial regression models, applied separately to tangents and curves, were used to model the frequency of accident occurrence. Model parameters were estimated by the Maximum Likelihood Method, and the Generalized Likelihood Ratio Test was applied to detect the significant variables to be included in the model equation. Goodness-of-fit was measured by means of both the explained fraction of total variation and the explained fraction of systematic variation. The Cumulative Residuals Method was also used to test the adequacy of a regression model throughout the range of each variable. The candidate set of explanatory variables was: length (L), curvature (1/R), annual average daily traffic (AADT), sight distance (SD), side friction coefficient (SFC), longitudinal slope (LS) and the presence of a junction (J). Separate prediction models for total crashes and for fatal and injury crashes

Topological data analysis of financial time series: Landscapes of crashes

NASA Astrophysics Data System (ADS)

Gidea, Marian; Katz, Yuri

2018-02-01

We explore the evolution of daily returns of four major US stock market indices during the technology crash of 2000, and the financial crisis of 2007-2009. Our methodology is based on topological data analysis (TDA). We use persistence homology to detect and quantify topological patterns that appear in multidimensional time series. Using a sliding window, we extract time-dependent point cloud data sets, to which we associate a topological space. We detect transient loops that appear in this space, and we measure their persistence. This is encoded in real-valued functions referred to as a 'persistence landscapes'. We quantify the temporal changes in persistence landscapes via their Lp-norms. We test this procedure on multidimensional time series generated by various non-linear and non-equilibrium models. We find that, in the vicinity of financial meltdowns, the Lp-norms exhibit strong growth prior to the primary peak, which ascends during a crash. Remarkably, the average spectral density at low frequencies of the time series of Lp-norms of the persistence landscapes demonstrates a strong rising trend for 250 trading days prior to either dotcom crash on 03/10/2000, or to the Lehman bankruptcy on 09/15/2008. Our study suggests that TDA provides a new type of econometric analysis, which complements the standard statistical measures. The method can be used to detect early warning signals of imminent market crashes. We believe that this approach can be used beyond the analysis of financial time series presented here.

Omitted variable bias in crash reduction factors.

DOT National Transportation Integrated Search

2015-09-01

Transportation planners and traffic engineers are increasingly turning to crash reduction factors to evaluate changes in road : geometric and design features in order to reduce crashes. Crash reduction factors are typically estimated based on segment...

Development of a real-time crash risk prediction model incorporating the various crash mechanisms across different traffic states.

PubMed

Xu, Chengcheng; Wang, Wei; Liu, Pan; Zhang, Fangwei

2015-01-01

This study aimed to identify the traffic flow variables contributing to crash risks under different traffic states and to develop a real-time crash risk model incorporating the varying crash mechanisms across different traffic states. The crash, traffic, and geometric data were collected on the I-880N freeway in California in 2008 and 2009. This study considered 4 different traffic states in Wu's 4-phase traffic theory. They are free fluid traffic, bunched fluid traffic, bunched congested traffic, and standing congested traffic. Several different statistical methods were used to accomplish the research objective. The preliminary analysis showed that traffic states significantly affected crash likelihood, collision type, and injury severity. Nonlinear canonical correlation analysis (NLCCA) was conducted to identify the underlying phenomena that made certain traffic states more hazardous than others. The results suggested that different traffic states were associated with various collision types and injury severities. The matching of traffic flow characteristics and crash characteristics in NLCCA revealed how traffic states affected traffic safety. The logistic regression analyses showed that the factors contributing to crash risks were quite different across various traffic states. To incorporate the varying crash mechanisms across different traffic states, random parameters logistic regression was used to develop a real-time crash risk model. Bayesian inference based on Markov chain Monte Carlo simulations was used for model estimation. The parameters of traffic flow variables in the model were allowed to vary across different traffic states. Compared with the standard logistic regression model, the proposed model significantly improved the goodness-of-fit and predictive performance. These results can promote a better understanding of the relationship between traffic flow characteristics and crash risks, which is valuable knowledge in the pursuit of improving

Costs of Crashes to Government, United States, 2008

PubMed Central

Miller, Ted R; Bhattacharya, Soma; Zaloshnja, Eduard; Taylor, Dexter; Bahar, Geni; David, Iuliana

2011-01-01

We estimated how much the Federal government and state/local government pay for different kinds of crashes in the United States. Government costs include reductions in an array of public services (emergency, incident management, vocational rehabilitation, coroner court processing of liability litigation), medical payments, social safety net assistance to the injured and their families, and taxes foregone because victims miss work. Government also pays when its employees crash while working and covers fringe benefits for crash-involved employees and their benefit-eligible dependents in non-work hours. We estimated government shares of crash costs by component. We applied those estimates to existing US Department of Transportation estimates of crash costs to society and employers. Government pays an estimated $35 billion annually because of crashes, an estimated 12.6% of the economic cost of crashes (Federal 7.1%, State/local 5.5%). Government bears a higher percentage of the monetary costs of injury crashes than fatal crashes or crashes involving property damage only. Government is increasingly recovering the medical cost of crashes from auto insurers. Nevertheless, medical costs and income and sales tax losses account for 75% of government's crash costs. For State/local government to break even on a 100%-State funded investment in road safety, the intervention would need to have an unrealistically high benefit-cost ratio of 34. Government invests in medical treatment of illness to save lives and improve quality of life. Curing a child's leukemia, for example, is not less costly than leaving that leukemia untreated. Safety should not be held to a different standard. PMID:22105409

Crash probability estimation via quantifying driver hazard perception.

PubMed

Li, Yang; Zheng, Yang; Wang, Jianqiang; Kodaka, Kenji; Li, Keqiang

2018-07-01

Crash probability estimation is an important method to predict the potential reduction of crash probability contributed by forward collision avoidance technologies (FCATs). In this study, we propose a practical approach to estimate crash probability, which combines a field operational test and numerical simulations of a typical rear-end crash model. To consider driver hazard perception characteristics, we define a novel hazard perception measure, called as driver risk response time, by considering both time-to-collision (TTC) and driver braking response to impending collision risk in a near-crash scenario. Also, we establish a driving database under mixed Chinese traffic conditions based on a CMBS (Collision Mitigation Braking Systems)-equipped vehicle. Applying the crash probability estimation in this database, we estimate the potential decrease in crash probability owing to use of CMBS. A comparison of the results with CMBS on and off shows a 13.7% reduction of crash probability in a typical rear-end near-crash scenario with a one-second delay of driver's braking response. These results indicate that CMBS is positive in collision prevention, especially in the case of inattentive drivers or ole drivers. The proposed crash probability estimation offers a practical way for evaluating the safety benefits in the design and testing of FCATs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Illinois crash facts and statistics, 2004-2005

DOT National Transportation Integrated Search

2005-01-01

The 2004-2005 Illinois Crash Facts & Statistics publication : is designed to provide the public with an overview of motor : vehicle crashes that occur in Illinois. This publication not : only consists of crash data but includes information abou...

Large truck and bus crash facts, 2010.

DOT National Transportation Integrated Search

2012-09-01

This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2010. Selected crash statistics on passenger : vehicles are also presen...

Large truck and bus crash facts, 2007.

DOT National Transportation Integrated Search

2009-03-01

This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2007. Selected crash statistics on passenger : vehicles are also presen...

Large truck and bus crash facts, 2011.

DOT National Transportation Integrated Search

2013-10-01

This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2011. Selected crash statistics on passenger : vehicles are also presen...

Large truck and bus crash facts, 2013.

DOT National Transportation Integrated Search

2015-04-01

This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and property damage only crashes involving large trucks and buses in 2013. Selected crash statistics on passenger vehicles are also presented ...

Large truck and bus crash facts, 2009.

DOT National Transportation Integrated Search

2011-10-01

This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2009. Selected crash statistics on passenger : vehicles are also presen...

Large truck and bus crash facts, 2012.

DOT National Transportation Integrated Search

2014-06-01

This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and property damage only crashes involving large trucks and buses in 2012. Selected crash statistics on passenger vehicles are also presented ...

Ohio traffic crash facts, 2003

DOT National Transportation Integrated Search

2004-04-28

Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2003. Data presented herein : represents the crash report forms as submitted ...

Ohio traffic crash facts, 2005

DOT National Transportation Integrated Search

2006-04-01

Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2005. Data presented herein : represents the crash report forms as submitted ...

Ohio traffic crash facts, 2002

DOT National Transportation Integrated Search

2003-12-01

Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2002. Data presented herein : represents the crash report forms as submitted ...

Ohio traffic crash facts, 2004

DOT National Transportation Integrated Search

2005-04-14

Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2004. Data presented herein : represents the crash report forms as submitted ...

Ohio traffic crash facts, 2006

DOT National Transportation Integrated Search

2007-07-01

Information contained in this report represents traffic crash data and supporting information from the Ohio : Integrated Traffic Records System (ITRS) for the calendar year 2006. Data presented herein represents the : crash report forms as submitted ...

Ohio traffic crash facts, 2001

DOT National Transportation Integrated Search

2002-06-05

Information contained in this report represents traffic crash data and supporting information from the Ohio : Integrated Traffic Records System (ITRS) for the calendar year 2001. Data presented herein represents the : crash report forms as submitted ...

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

Pedal error crashes : traffic tech.

DOT National Transportation Integrated Search

2012-04-01

This project examined the prevalence of crashes in which the : driver pressed the accelerator pedal when he or she intended : to press the brake pedal, and the characteristics associated with : these crashes. : Technical literature published between ...

2006 Oregon traffic crash summary

DOT National Transportation Integrated Search

2007-06-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

2007 Oregon traffic crash summary

DOT National Transportation Integrated Search

2008-07-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

2005 Oregon traffic crash summary

DOT National Transportation Integrated Search

2006-06-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

Crash Data Safety Factors Evaluation

DOT National Transportation Integrated Search

2017-11-30

The purpose of this project was to identify annual trends and contributory factors of crashes involving mature drivers, vulnerable road users, fatal and injury crashes involving guiderail, and collisions resulting from vehicle failures. Three years o...

2003 Oregon traffic crash summary

DOT National Transportation Integrated Search

2004-10-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring on city streets, county roads and state highways. The data supports various local, county and state traffic safety programs, engineering and plan...

Traffic crash statistics report, 2001

DOT National Transportation Integrated Search

2002-06-21

This report contains data from the department's crash database, compiled from traffic crash reports completed by state and local law enforcement agencies. While progress has been made in reducing deaths, injuries and economic losses on Florida's high...

Traffic crash statistics report, 1999

DOT National Transportation Integrated Search

2000-05-17

This report contains : data from the Departments crash database, compiled from traffic crash reports completed by : state and local law enforcement agencies. The mission of the Department of Highway Safety : and Motor Vehicles is to make highways ...

Crash reduction factor (CRF) update.

DOT National Transportation Integrated Search

2011-01-01

Recent research conducted by the Federal Highway Administration (FHWA) produced the Desktop Reference for : Crash Reduction Factors, FHWA Report No. FHWA-SA-07-015, published in September 2007. These crash : reduction factors are commonly used by sta...

Developing Louisiana crash reduction factors.

DOT National Transportation Integrated Search

2013-10-01

The Louisiana Strategic Highway Safety Plan is to reach the goal of Destination Zero Death on Louisiana : roadways. This tall order calls for implementing all feasible crash countermeasures. A great number of crash : countermeasures have been identif...

2002 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2003-11-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates for specific sections : of State Highways. This report differs from the State Highway Crash Ra...

GIS-Based crash referencing and analysis system

DOT National Transportation Integrated Search

1999-02-01

One area where a Geographic Information System (GIS) has yet to be extensively applied is in the analysis of crash data. Computerized crash analysis systems in which crash data, roadway inventory data, and traffic operations data can be merged are us...

2003 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2005-04-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates for specific sections of : State Highways. This report differs from the State Highway Crash Ra...

2004 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2005-11-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates and Truck-At-Fault : crash rates for specific sections of State Highways. This report differs ...

2006 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2007-08-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates and Truck-At-Fault : crash rates for specific sections of State Highways. This report differs ...

2005 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2006-01-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates and Truck-At-Fault : crash rates for specific sections of State Highways. This report differs ...

2007 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2008-11-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates and Truck-At-Fault : crash rates for specific sections of State Highways. This report differs ...

Fatal Crash Involvements -- What Are The Odds?

DOT National Transportation Integrated Search

1997-07-01

The risk of being involved in a fatal crash varies considerably depending on : specific crash characteristics, i.e., those of the driver, vehicle and : environment. A generally accepted measure of the risk of a fatal crash is the : ratio between the ...

2008 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2009-10-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its : purpose is to assist readers in computing Motor Carrier crash rates and Truck-At-Fault : crash rates for specific sections of State Highways. This report differs ...

XB-70A during startup and ramp taxi

NASA Technical Reports Server (NTRS)

1968-01-01

The XB-70 was the world's largest experimental aircraft. Capable of flight at speeds of three times the speed of sound (2,000 miles per hour) at altitudes of 70,000 feet, the XB-70 was used to collect in-flight information for use in the design of future supersonic aircraft, military and civilian. This 35-second video shows the startup of the XB-70A airplane engines, the beginning of its taxi to the runway, and a turn on the ramp that shows the unique configuration of this aircraft.

Ohio traffic crash facts, 2000

DOT National Transportation Integrated Search

2001-08-06

Information contained in this report represents traffic crash data and supporting information from the Ohio Integrated Traffic Records System for the calendar year of 2000. Data presented herein represents the crash report forms as submitted to the O...

2002 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2003-09-01

2002 Facts and Figures : 805 persons were killed in Wisconsin motor vehicle traffic crashes (36% involved alcohol, : 34% involved speed, and 18% involved both speed and alcohol). : 57,776 persons were injured in 39,634 reported injury crashes...

1999 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2000-09-01

1999 Facts and Figures : 744 persons were killed in Wisconsin motor vehicle traffic crashes. : (36% involved Alcohol, 27% involved Speed, and 14% involved both Speed and Alcohol). : 61,577 persons were injured in 41,345 reported injury crashe...

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.

2001 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2002-11-01

This is a three-part report. This report differs from the State Highway Crash Rate : Tables in that it contains crash data on motor carrier crashes only, and does not include : data for highway spurs, frontage roads, and the non-add segments of...

2000 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2002-01-01

This is a three-part report. This report differs from the State Highway Crash Rate : Tables in that it contains crash data on motor carrier crashes only, and does not include : data for highway spurs, frontage roads, and the non-add segments of...

1999 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2000-12-01

This is a three-part report. This report differs from the State Highway Crash Rate : Tables in that it contains crash data on motor carrier crashes only, and does not include : data for highway spurs, frontage roads, and the non-add segments of...

2009 Oregon motor carrier crash rate tables

DOT National Transportation Integrated Search

2010-11-01

The State Highway Motor Carrier Crash Rate Tables is a publication in four parts. Its purpose is to assist readers in computing Motor Carrier crash rates and Truck-At-Fault crash rates for specific sections of State Highways. This report differs from...

Analysis of lane change crashes

DOT National Transportation Integrated Search

2003-03-01

This report defines the problem of lane change crashes in the United States (U.S.) based on data from the 1999 National Automotive Sampling System/General Estimates System (GES) crash database of the National Highway Traffic Safety Administration. Th...

Traffic crash statistics report, 2010

DOT National Transportation Integrated Search

2010-01-01

This report is compiled from long form traffic crash reports submitted by state and local law enforcement agencies and the Department aggregates the information for this report. In general, the 2010 crash statistics show a positive trend in decreases...

2009 Oregon traffic crash summary

DOT National Transportation Integrated Search

2010-09-01

The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

2008 Oregon traffic crash summary

DOT National Transportation Integrated Search

2009-09-01

The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

2010 Oregon traffic crash summary

DOT National Transportation Integrated Search

2011-08-01

The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

Traffic crash statistics report, 2008

DOT National Transportation Integrated Search

2009-01-01

This report is compiled from long form traffic crash reports submitted by state and local law enforcement agencies and the Department aggregates the information for this report. In general, the 2008 crash statistics show a positive trend in decreases...

Traffic crash statistics report, 2009

DOT National Transportation Integrated Search

2010-06-23

This report is compiled from long form traffic crash reports submitted by state and local law enforcement agencies. The Department summarizes all the submitted information for this report. in general, the 2009 crash statistics show a positive trend i...

2001 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2002-09-01

2001 Facts and Figures: 764 persons were killed in Wisconsin motor vehicle traffic crashes (40% involved alcohol, 32% involved : speed, and 16% involved both speed and alcohol). : 58,279 persons were injured in 39,358 reported injury crashes and ...

Alternative Fuels Data Center: Happy Cab Fuels Taxi Fleet With CNG

Science.gov Websites

Happy Cab Fuels Taxi Fleet With CNG Find out how a cab company in Omaha, Nebraska, saves money fueling Go Electric in Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels

Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in

Science.gov Websites

electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Columbus, OhioA> Yellow Cab Converts Taxis to Propane in Columbus, Ohio to someone by E-mail how Yellow Cab is overhauling their fleet in Columbus, Ohio, with propane power. For information about

Evaluation of a full-time ride service program : Aspen, Colorado's Tipsy Taxi service

DOT National Transportation Integrated Search

2000-10-01

This report summarizes a study of Aspen, Colorado's Tipsy Taxi ride service program. This service, which provides a free ride home for persons who are too intoxicated to drive, has been in place since December 1983. Funded through donations from the ...

Aircraft Crash Survival Design Guide. Volume 2. Aircraft Crash Environment and Human Tolerance

DTIC Science & Technology

1980-01-01

anthropometry , and crash test dummies, all of which serves as background for the design information presented in the other volumes. .I / V. L...Aeromedical Institute furnished assistance in locat- ing recent information on human tolerance, anthropometry , and crash test dummies. .3 TABLE OF CONTENTS...83 6.1 INTRODUCTION . . . . . . .. ..... 83 6.2 ANTHROPOMETRY . . . . . . 83 6.2.1 Conventional Anthropometric Measurements

Marijuana use and car crash injury.

PubMed

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

2005-05-01

To investigate the relationship between marijuana use prior to driving, habitual marijuana use and car crash injury. Population based case-control study in Auckland, New Zealand. Case vehicles were all cars involved in crashes in which at least one occupant was hospitalized or killed anywhere in the Auckland region, and control vehicles were a random sample of cars driving on Auckland roads. The drivers of 571 case and 588 control vehicles completed a structured interview. Self reported marijuana use in the 3 hours prior to the crash/survey and habitual marijuana use over the previous 12 months were recorded, along with a range of other variables potentially related to crash risk. The main outcome measure was hospitalization or death of a vehicle occupant due to car crash injury. Acute marijuana use was significantly associated with car crash injury, after controlling for the confounders age, gender, ethnicity, education level, passenger carriage, driving exposure and time of day (OR 3.9, 95% CI 1.2-12.9). However, after adjustment for these confounders plus other risky driving at the time of the crash (blood alcohol concentration, seat-belt use, travelling speed and sleepiness score), the effect of acute marijuana intake was no longer significant (OR 0.8, 95% CI 0.2-3.3). There was a strong significant association between habitual use and car crash injury after adjustment for all the above confounders plus acute use prior to driving (OR 9.5, 95% CI 2.8-32.3). This population-based case-control study indicates that habitual use of marijuana is strongly associated with car crash injury. The nature of the relationship between marijuana use and risk-taking is unclear and needs further research. The prevalence of marijuana use in this driving population was low, and acute use was associated with habitual marijuana use, suggesting that intervention strategies may be more effective if they are targeted towards high use groups.

41 CFR 301-10.421 - How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy transportation driver? 301-10.421 Section 301... tip to a taxi, shuttle service, or courtesy transportation driver? An amount which your agency...

41 CFR 301-10.421 - How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy transportation driver? 301-10.421 Section 301... tip to a taxi, shuttle service, or courtesy transportation driver? An amount which your agency...

2005 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2006-11-01

2005 Facts and Figures : 801 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of : over two lives lost each day on Wisconsin traffic arteries. : 53,462 persons were injured in 37,515 reported injury crashes a...

Mitigating Wind Induced Truck Crashes

DOT National Transportation Integrated Search

2009-12-25

Dangerous weather and high wind in particular, is a common contributing factor in truck crashes. High wind speeds have been documented as a perennial cause of truck crashes in Kansas and other Great Plains states. The possibility of reducing such cra...

Fatal single vehicle motorcycle crashes

DOT National Transportation Integrated Search

2001-10-01

More than 38,000 motorcyclists have died in single vehicle motorcycle crashes between 1975 and 1999. Motorcyclist : fatalities in single vehicle crashes decreased each year from 1990 to 1996, reaching a historic low of 937 in 1996 and : again in 1997...

Analysis of crossing path crashes

DOT National Transportation Integrated Search

2001-07-01

This report defines the problem of crossing path crashes in the United States. This crash type involves one moving vehicle that cuts across the path of another when their initial approach comes from either lateral or opposite directions and they typi...

Connected motorcycle crash warning interfaces.

DOT National Transportation Integrated Search

2016-01-15

Crash warning systems have been deployed in the high-end vehicle market segment for some time and are trickling down to additional motor vehicle industry segments each year. The motorcycle segment, however, has no deployed crash warning system to dat...

Developing Louisiana crash reduction factors.

DOT National Transportation Integrated Search

2009-12-01

Approximately 1,000 people lose their lives each year in traffic crashes on : Louisianas roadways, and 50,000 are injured. Traffic crashes cost the : citizens of Louisiana $6.03 billion each year, which accounts for about : $2,104 for every licens...

2000 Wisconsin traffic crash facts

DOT National Transportation Integrated Search

2001-10-01

2000 Facts and Figures: 801 persons were killed in Wisconsin motor vehicle traffic crashes (38% invloved alcohol, 29% involved speed, and 15% involved both speed and alcohol). 63,890 persons were injured in 43, 145 reported injury crashes and 718 fat...

Developing Louisiana crash reduction factors : [tech summary].

DOT National Transportation Integrated Search

2013-10-01

Although, like the rest of the country, Louisiana has made great strides in reducing the number of crashes, particularly : fatal crashes, in recent years, our fatal crash rate of 1.56 is still higher than the national average of 1.10 in 2010. The vis...

Impulsivity and risky decision making among taxi drivers in Hong Kong: An event-related potential study.

PubMed

Cheng, Andy S K; Ting, K H; Liu, Karen P Y; Ba, Yutao

2016-10-01

Taxi drivers play an important role in providing safe and professional public transport services. However, they tend to be more involved than other professional driver groups in accidents caused by deliberate recklessness. This study used an event-related potential (ERP) experiment to examine risk-taking behavior arising from impulsivity by comparing the underlying neural processes of taxi drivers with and without traffic offence records in Hong Kong. A sample of 15 traffic offenders and 15 nonoffenders, matched by sociodemographic characteristics, was recruited. The results show that the offender group demonstrated significantly less negative-going (less negative) feedback-related negativity but more positive-going (more positive) feedback-related P300 when than with their nonoffending counterparts. These findings show that taxi drivers with traffic offence records were less sensitive to the consequences of behavior and more attuned to the magnitude of potential reward. In addition, behavioral data revealed that they were more willing to make risky decisions. All these characteristics pertain to impulsive personality traits. Based on these findings, we can conclude that the offenders in this sample were more impulsive than their nonoffending counterparts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identifying work-related motor vehicle crashes in multiple databases.

PubMed

Thomas, Andrea M; Thygerson, Steven M; Merrill, Ray M; Cook, Lawrence J

2012-01-01