Electrochemistry in hollow-channel paper analytical devices.

PubMed

Renault, Christophe; Anderson, Morgan J; Crooks, Richard M

2014-03-26

In the present article we provide a detailed analysis of fundamental electrochemical processes in a new class of paper-based analytical devices (PADs) having hollow channels (HCs). Voltammetry and amperometry were applied under flow and no flow conditions yielding reproducible electrochemical signals that can be described by classical electrochemical theory as well as finite-element simulations. The results shown here provide new and quantitative insights into the flow within HC-PADs. The interesting new result is that despite their remarkable simplicity these HC-PADs exhibit electrochemical and hydrodynamic behavior similar to that of traditional microelectrochemical devices.

Self-organized phenomena of pedestrian counterflow through a wide bottleneck in a channel

NASA Astrophysics Data System (ADS)

Dong, Li-Yun; Lan, Dong-Kai; Li, Xiang

2016-09-01

The pedestrian counterflow through a bottleneck in a channel shows a variety of flow patterns due to self-organization. In order to reveal the underlying mechanism, a cellular automaton model was proposed by incorporating the floor field and the view field which reflects the global information of the studied area and local interactions with others. The presented model can well reproduce typical collective behaviors, such as lane formation. Numerical simulations were performed in the case of a wide bottleneck and typical flow patterns at different density ranges were identified as rarefied flow, laminar flow, interrupted bidirectional flow, oscillatory flow, intermittent flow, and choked flow. The effects of several parameters, such as the size of view field and the width of opening, on the bottleneck flow are also analyzed in detail. The view field plays a vital role in reproducing self-organized phenomena of pedestrian. Numerical results showed that the presented model can capture key characteristics of bottleneck flows. Project supported by the National Basic Research Program of China (Grant No. 2012CB725404) and the National Natural Science Foundation of China (Grant Nos. 11172164 and 11572184).

Road User Behaviors At Pedestrian Hybrid Beacons

DOT National Transportation Integrated Search

2016-06-01

The pedestrian hybrid beacon (PHB) has shown great potential for improving pedestrian safety and driver yielding. However, questions remain regarding under what roadway conditions such as crossing distance (i.e., number of lanes) and posted speed ...

Distraction and pedestrian safety: how talking on the phone, texting, and listening to music impact crossing the street.

PubMed

Schwebel, David C; Stavrinos, Despina; Byington, Katherine W; Davis, Tiffany; O'Neal, Elizabeth E; de Jong, Desiree

2012-03-01

As use of handheld multimedia devices has exploded globally, safety experts have begun to consider the impact of distraction while talking, text-messaging, or listening to music on traffic safety. This study was designed to test how talking on the phone, texting, and listening to music may influence pedestrian safety. 138 college students crossed an interactive, semi-immersive virtual pedestrian street. They were randomly assigned to one of four groups: crossing while talking on the phone, crossing while texting, crossing while listening to a personal music device, or crossing while undistracted. Participants distracted by music or texting were more likely to be hit by a vehicle in the virtual pedestrian environment than were undistracted participants. Participants in all three distracted groups were more likely to look away from the street environment (and look toward other places, such as their telephone or music device) than were undistracted participants. Findings were maintained after controlling for demographics, walking frequency, and media use frequency. Distraction from multimedia devices has a small but meaningful impact on college students' pedestrian safety. Future research should consider the cognitive demands of pedestrian safety, and how those processes may be impacted by distraction. Policymakers might consider ways to protect distracted pedestrians from harm and to reduce the number of individuals crossing streets while distracted. Copyright © 2011 Elsevier Ltd. All rights reserved.

Distraction and Pedestrian Safety: How Talking on the Phone, Texting, and Listening to Music Impact Crossing the Street

PubMed Central

Schwebel, David C.; Stavrinos, Despina; Byington, Katherine W.; Davis, Tiffany; O’Neal, Elizabeth E.; de Jong, Desiree

2011-01-01

As use of handheld multimedia devices has exploded globally, safety experts have begun to consider the impact of distraction while talking, text-messaging, or listening to music on traffic safety. This study was designed to test how talking on the phone, texting, and listening to music may influence pedestrian safety. 138 college students crossed an interactive, semi-immersive virtual pedestrian street. They were randomly assigned to one of four groups: crossing while talking on the phone, crossing while texting, crossing while listening to a personal music device, or crossing while undistracted. Participants distracted by music or texting were more likely to be hit by a vehicle in the virtual pedestrian environment than were undistracted participants. Participants in all three distracted groups were more likely to look away from the street environment (and look toward other places, such as their telephone or music device) than were undistracted participants. Findings were maintained after controlling for demographics, walking frequency, and media use frequency. Distraction from multimedia devices has a small but meaningful impact on college students’ pedestrian safety. Future research should consider the cognitive demands of pedestrian safety, and how those processes may be impacted by distraction. Policymakers might consider ways to protect distracted pedestrians from harm and to reduce the number of individuals crossing streets while distracted. PMID:22269509

Influencing Factors on Conflicts of Turning Vehicles and Pedestrians at Intersections

DOT National Transportation Integrated Search

2015-09-30

Vehicle drivers are expected to yield to pedestrians when there are conflicts, however drivers may fail to see pedestrians and react to pedestrians when they are influenced by various factors such as the surrounding traffic, intersection geometric, v...

Evaluation of alternative pedestrian control devices.

DOT National Transportation Integrated Search

2012-03-01

A literature review, field study of Rectangular Rapid Flashing Beacon (RRFB) installations in Oregon, and a static survey : on the sequencing of the Pedestrian Hybrid Beacon (PHB) were completed. : The field study conducted in this project was design...

Empirical Behavioral Models to Support Alternative Tools for the Analysis of Mixed-Priority Pedestrian-Vehicle Interaction in a Highway Capacity Context

PubMed Central

Rouphail, Nagui M.

2011-01-01

This paper presents behavioral-based models for describing pedestrian gap acceptance at unsignalized crosswalks in a mixed-priority environment, where some drivers yield and some pedestrians cross in gaps. Logistic regression models are developed to predict the probability of pedestrian crossings as a function of vehicle dynamics, pedestrian assertiveness, and other factors. In combination with prior work on probabilistic yielding models, the results can be incorporated in a simulation environment, where they can more fully describe the interaction of these two modes. The approach is intended to supplement HCM analytical procedure for locations where significant interaction occurs between drivers and pedestrians, including modern roundabouts. PMID:21643488

32 CFR 636.26 - Pedestrian's rights and duties.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.26 Pedestrian's rights and duties. (a) Pedestrians will obey all traffic control devices and regulations, unless directed to do otherwise by the Military Police. (b) When traffic-control...

Pedestrian Safety Treatments for Signalized Intersections : Training Course Development

DOT National Transportation Integrated Search

2017-11-01

When drivers make left turns during a permissive turn phase, they must yield to pedestrians as well as oncoming through vehicles. Left-turning drivers sometimes overlook pedestrians in the crosswalk while watching the opposing intersection approach. ...

Features of pedestrian behavior in car-to-pedestrian contact situations in near-miss incidents in Japan.

PubMed

Matsui, Yasuhiro; Hitosugi, Masahito; Doi, Tsutomu; Oikawa, Shoko; Takahashi, Kunio; Ando, Kenichi

2013-01-01

The objective of this study is to evaluate the severe conditions between car-to-pedestrian near-miss situations using pedestrian time-to-vehicle (pedestrian TTV) which is the time when the pedestrian would reach the forward moving car line. Since the information available from the real-world accidents was limited, the authors focused on the near-miss situations captured by driving recorders installed in passenger cars. In their previous study, the authors found there were some similarities between accidents and near-miss incidents. It was made clear that the situations in pedestrians' accidents could be estimated from the near-miss incident data which included motion pictures capturing pedestrian behaviors. In their previous study, the vehicle time-to-collision (vehicle TTC) was investigated from the near-miss incident data. The authors analyzed data for 101 near-miss car-to-pedestrian incident events in which pedestrians were crossing the roads in front of a forward-moving car at an intersection or on a straight road. Using a video of near-miss car-to-pedestrian incidents captured by drive recorders and collected by the Society of Automotive Engineers of Japan (J-SAE) from 2005 to 2009, the pedestrian TTV was calculated. Based on the calculated pedestrian TTV, one of the severe conditions between car-to-pedestrian near-miss situations was evaluated for pedestrians who emerged from behind an obstruction such as a building, a parked vehicle and a moving vehicle. Focusing on the cases of the pedestrians who emerged from behind an obstruction, the averages of the vehicle TTC and pedestrian TTV were 1.31 and 1.05 seconds, respectively, and did not demonstrate a significant difference. Since the averages of the vehicle TTC and pedestrian TTV were similar, there would be a higher possibility of the contact between a car and pedestrian if the driver and pedestrian were not paying any attention. The authors propose that a moving speed of a pedestrian surrogate "dummy

Development of guidelines for pedestrian safety treatments at signalized intersections.

DOT National Transportation Integrated Search

2012-01-01

For intersections with a permissive or protected-permissive left-turn mode, pedestrians cross during the : permissive period. This operation requires the left-turn driver to yield to both opposing vehicles and : pedestrians, prior to accepting a gap ...

Oriented regions grouping based candidate proposal for infrared pedestrian detection

NASA Astrophysics Data System (ADS)

Wang, Jiangtao; Zhang, Jingai; Li, Huaijiang

2018-04-01

Effectively and accurately locating the positions of pedestrian candidates in image is a key task for the infrared pedestrian detection system. In this work, a novel similarity measuring metric is designed. Based on the selective search scheme, the developed similarity measuring metric is utilized to yield the possible locations for pedestrian candidate. Besides this, corresponding diversification strategies are also provided according to the characteristics of the infrared thermal imaging system. Experimental results indicate that the presented scheme can achieve more efficient outputs than the traditional selective search methodology for the infrared pedestrian detection task.

Experiential Exposure to Texting and Walking in Virtual Reality: A Randomized Trial to Reduce Distracted Pedestrian Behavior

PubMed Central

Schwebel, David C.; McClure, Leslie A.; Porter, Bryan E.

2017-01-01

intervention compared to a control campus not exposed to the intervention. Discussion The intervention created some change in self-reported intentions and thoughts but did not create significant behavior change on the campus exposed to it. Further efforts to develop interventions that will yield a reduction in distracted pedestrian behavior are needed. PMID:28279843

Experiential exposure to texting and walking in virtual reality: A randomized trial to reduce distracted pedestrian behavior.

PubMed

Schwebel, David C; McClure, Leslie A; Porter, Bryan E

2017-05-01

exposed to the intervention. The intervention created some change in self-reported intentions and thoughts but did not create significant behavior change on the campus exposed to it. Further efforts to develop interventions that will yield a reduction in distracted pedestrian behavior are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Development of Statewide Guidelines for Implementing Leading Pedestrian Intervals in Florida

DOT National Transportation Integrated Search

2017-12-01

Pedestrian safety is an ongoing major concern throughout the United States and is one of the highest priorities for the Florida Department of Transportation (FDOT). Vehicles often fail to yield to pedestrians at intersections, especially when pedestr...

Severity of child pedestrian injuries due to bonnet-type-vehicle collision.

PubMed

Hitosugi, Masahito; Kawato, Hitoshi; Gomei, Sayaka; Mizuno, Koji; Tokudome, Shogo

2013-10-01

The aim of this study was to clarify the pattern of child pedestrian injury, injury severity, and its relation to collision velocity in bonnet-type-vehicle collision. In-depth data were retrospectively collected from the Institute for Traffic Accident Research and Data Analysis on pedestrians younger than 13 years old with any bodily injuries from collisions with bonnet-type vehicles between 1993 and 2004. Forty-seven patients from 43 collisions with a mean age of 6.9 ± 2.5 years were included in the study. Injury severity was not significantly different between patients who were hit by the front of the vehicle and those who were hit by the side of the vehicle. In front collisions, impact with the vehicle was associated with significantly higher Abbreviated Injury Scale (AIS) scores than those for impact with the road, especially for the lower extremities (mean: 1.2 vs 0.2, P < 0.001). Injury severity of the lower extremities and collision velocity were examined. The estimated collision velocity of the vehicle was not significantly different between patients with lower extremity AIS scores of 0 or 1 and those of 2 or 3. Some pediatric pedestrians suffer from collisions with bonnet-type vehicles without lower extremity fractures owing to the characteristics of child pedestrians. Providing injury prevention programs for children in communities and schools, developing active safety devices in the vehicle, and modifying the vehicle body to a pediatric pedestrian-friendly structure may increase pedestrian protection. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

Energy conversion device with support member having pore channels

DOEpatents

Routkevitch, Dmitri [Longmont, CO; Wind, Rikard A [Johnstown, CO

2014-01-07

Energy devices such as energy conversion devices and energy storage devices and methods for the manufacture of such devices. The devices include a support member having an array of pore channels having a small average pore channel diameter and having a pore channel length. Material layers that may include energy conversion materials and conductive materials are coaxially disposed within the pore channels to form material rods having a relatively small cross-section and a relatively long length. By varying the structure of the materials in the pore channels, various energy devices can be fabricated, such as photovoltaic (PV) devices, radiation detectors, capacitors, batteries and the like.

Influence of children pedestrian behaviour on pedestrian space usage

NASA Astrophysics Data System (ADS)

Makalew, F. P.; Adisasmita, S. A.; Wunas, S.; Hamid, S.

2017-11-01

School children pedestrian behaviour can be seen along their journey to and from school. Pedestrian spaces used by children are places available in urban and rural areas including streets with and without pedestrian pathways. Samples data are collected from 23 elementary schools in urban and rural areas in North Sulawesi, Indonesia in the form of video records and photos taken. The aim of this research is to analyse children pedestrian behaviour and its influence on the space usage on pedestrian areas. Method of analysis is a comparative study on urban and rural areas. Results of this research are types of behaviour, factors that influence the behaviour, physical condition of pedestrian areas and space usage by children. The behaviours are duck-line walking, running, playing, walking backward and walking with bare foot in which running is the main behaviour. These behaviours are influenced by factors including following friends and responding to acts. There are similarities and differences between pedestrian space usage in urban and rural areas. Space use by children pedestrian demonstrates the way pedestrian areas should be planned. Space usage by children pedestrian indicates that there is a need of evaluation of the space available considering pedestrian children behaviour.

High-visibility enforcement on driver compliance with pedestrian right-of-way laws.

DOT National Transportation Integrated Search

2013-08-01

This study developed and evaluated strategies to increase driver yielding to pedestrians on a citywide basis using high-visibility pedestrian right-of-way enforcement. After a site recruitment process, Gainesville, Florida, participated in the projec...

Vehicle-pedestrian collisions - Aspects regarding pedestrian kinematics, dynamics and biomechanics

NASA Astrophysics Data System (ADS)

Petrescu, L.; Petrescu, Al

2017-10-01

Vehicle-pedestrian collisions result in a substantial number of pedestrian fatalities and injuries worldwide. Concern continues to limit and reduce the tragic consequences suffered by pedestrians involved in road accidents, caused the vehicle-pedestrian accident reconstruction become an important area and distinctly outlined in the reconstruction of road incidents involving vehicle. This paper analyzes the dynamics of vehicle-pedestrian impact influence over pedestrian biomechanics, which is directly connected with the severity of injury after contact with the vehicle profile and with the place where the pedestrian is projected. The main goal of this paper is to highlight some features of reconstruction of road accidents involving pedestrian, looking at the kinematics and dynamics of pedestrian impact for a better understanding of the phenomena that occur. The study on the dynamics and biomechanics of the pedestrian hit by the vehicle is useful in order to understand how the injuries, including the lethal ones, are generated in the collision, what is essential in road accidents reconstruction.

Kinematic responses and injuries of pedestrian in car-pedestrian collisions

NASA Astrophysics Data System (ADS)

Teng, T. L.; Liang, C. C.; Hsu, C. Y.; Tai, S. F.

2017-10-01

How to protect pedestrians and reduce the collision injury has gradually become the new field of automotive safety research and focus in the world. Many engineering studies have appeared and their purpose is trying to reduce the pedestrian injuries caused by traffic accident. The physical model involving impactor model and full scale pedestrian model are costly when taking the impact test. This study constructs a vehicle-pedestrian collision model by using the MADYMO. To verify the accuracy of the proposed vehicle-pedestrian collision model, the experimental data are used in the pedestrian model test. The proposed model also will be applied to analyze the kinematic responses and injuries of pedestrian in collisions in this study. The modeled results can help assess the pedestrian friendliness of vehicles and assist in the future development of pedestrian friendliness vehicle technologies.

Preventing child pedestrian injury: pedestrian education or traffic calming?

PubMed

Roberts, I; Ashton, T; Dunn, R; Lee-Joe, T

1994-06-01

The traditional approach to the prevention of child pedestrian injuries in New Zealand is pedestrian education. However, none of the programs currently being implemented in New Zealand have ever been shown to reduce injury rates. The allocation of scarce resources to pedestrian education must therefore be questioned. In this paper we estimate the number of serious child pedestrian injuries which might be prevented if the resources allocated to pedestrian education were allocated instead to environmental approaches, in particular, to traffic calming. It is estimated that approximately 18 hospitalisations of child pedestrians could be prevented each year under this alternative resource allocation, disregarding any other benefits of traffic calming. These results emphasise the need to consider the potential sacrifices involved in the allocation of scarce resources to child pedestrian education.

Effect of gate skirts on pedestrian behavior at highway-rail grade crossings

DOT National Transportation Integrated Search

2013-12-31

The Federal Railroad Administration was interested in evaluating one type of pedestrian safety device, commonly known as gate skirts, that consists of a secondary horizontal hanging gate under the existing pedestrian gate to better block access to th...

The risk of pedestrian collisions with peripheral visual field loss.

PubMed

Peli, Eli; Apfelbaum, Henry; Berson, Eliot L; Goldstein, Robert B

2016-12-01

Patients with peripheral field loss complain of colliding with other pedestrians in open-space environments such as shopping malls. Field expansion devices (e.g., prisms) can create artificial peripheral islands of vision. We investigated the visual angle at which these islands can be most effective for avoiding pedestrian collisions, by modeling the collision risk density as a function of bearing angle of pedestrians relative to the patient. Pedestrians at all possible locations were assumed to be moving in all directions with equal probability within a reasonable range of walking speeds. The risk density was found to be highly anisotropic. It peaked at ≈45° eccentricity. Increasing pedestrian speed range shifted the risk to higher eccentricities. The risk density is independent of time to collision. The model results were compared to the binocular residual peripheral island locations of 42 patients with forms of retinitis pigmentosa. The natural residual island prevalence also peaked nasally at about 45° but temporally at about 75°. This asymmetry resulted in a complementary coverage of the binocular field of view. Natural residual binocular island eccentricities seem well matched to the collision-risk density function, optimizing detection of other walking pedestrians (nasally) and of faster hazards (temporally). Field expansion prism devices will be most effective if they can create artificial peripheral islands at about 45° eccentricities. The collision risk and residual island findings raise interesting questions about normal visual development.

High process yield rates of thermoplastic nanofluidic devices using a hybrid thermal assembly technique.

PubMed

Uba, Franklin I; Hu, Bo; Weerakoon-Ratnayake, Kumuditha; Oliver-Calixte, Nyote; Soper, Steven A

2015-02-21

Over the past decade, thermoplastics have been used as alternative substrates to glass and Si for microfluidic devices because of the diverse and robust fabrication protocols available for thermoplastics that can generate high production rates of the desired structures at low cost and with high replication fidelity, the extensive array of physiochemical properties they possess, and the simple surface activation strategies that can be employed to tune their surface chemistry appropriate for the intended application. While the advantages of polymer microfluidics are currently being realized, the evolution of thermoplastic-based nanofluidic devices is fraught with challenges. One challenge is assembly of the device, which consists of sealing a cover plate to the patterned fluidic substrate. Typically, channel collapse or substrate dissolution occurs during assembly making the device inoperable resulting in low process yield rates. In this work, we report a low temperature hybrid assembly approach for the generation of functional thermoplastic nanofluidic devices with high process yield rates (>90%) and with a short total assembly time (16 min). The approach involves thermally sealing a high T(g) (glass transition temperature) substrate containing the nanofluidic structures to a cover plate possessing a lower T(g). Nanofluidic devices with critical feature sizes ranging between 25-250 nm were fabricated in a thermoplastic substrate (T(g) = 104 °C) and sealed with a cover plate (T(g) = 75 °C) at a temperature significantly below the T(g) of the substrate. Results obtained from sealing tests revealed that the integrity of the nanochannels remained intact after assembly and devices were useful for fluorescence imaging at high signal-to-noise ratios. The functionality of the assembled devices was demonstrated by studying the stretching and translocation dynamics of dsDNA in the enclosed thermoplastic nanofluidic channels.

Pedestrians

DOT National Transportation Integrated Search

2008-01-01

In 2008, 4,378 pedestrians were killed in traffic crashes in the United States a decrease of 16 percent from the 5,228 pedestrians killed in 1998. On average, a pedestrian is killed in a traffic crash every 120 minutes and injured in a traffic cr...

Reducing Conflicts between Motor Vehicles and Pedestrians: The Separate and Combined Effects of Pavement Markings and a Sign Prompt

ERIC Educational Resources Information Center

Huybers, Sherry; Van Houten, Ron; Malenfant, J.E. Louis

2004-01-01

The effects of a symbolic "yield here to pedestrians" sign and advance yield pavement markings on pedestrian/motor vehicle conflicts, motorists' yielding behavior, and the distance motorists' yield in advance of crosswalks were evaluated at multilane crosswalks at uncontrolled T intersections. In Experiment 1, the sign, when used alone, reduced…

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Winkelmann, Joseph P. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface is a state machine, such as an ASIC, that operates independent of a processor in communicating with the bus controller and data channels.

Comparison of Driver Yielding for Three Rapid-flashing Patterns Used with Pedestrian Crossing Signs

DOT National Transportation Integrated Search

2015-05-01

Flashing traffic control devices can help draw drivers attention to the traffic control device and to the area around the device. An example of a device that has resulted in significant improvements in increasing driver yielding to crossing pedest...

Device for modular input high-speed multi-channel digitizing of electrical data

DOEpatents

VanDeusen, A.L.; Crist, C.E.

1995-09-26

A multi-channel high-speed digitizer module converts a plurality of analog signals to digital signals (digitizing) and stores the signals in a memory device. The analog input channels are digitized simultaneously at high speed with a relatively large number of on-board memory data points per channel. The module provides an automated calibration based upon a single voltage reference source. Low signal noise at such a high density and sample rate is accomplished by ensuring the A/D converters are clocked at the same point in the noise cycle each time so that synchronous noise sampling occurs. This sampling process, in conjunction with an automated calibration, yields signal noise levels well below the noise level present on the analog reference voltages. 1 fig.

Device for modular input high-speed multi-channel digitizing of electrical data

DOEpatents

VanDeusen, Alan L.; Crist, Charles E.

1995-09-26

A multi-channel high-speed digitizer module converts a plurality of analog signals to digital signals (digitizing) and stores the signals in a memory device. The analog input channels are digitized simultaneously at high speed with a relatively large number of on-board memory data points per channel. The module provides an automated calibration based upon a single voltage reference source. Low signal noise at such a high density and sample rate is accomplished by ensuring the A/D converters are clocked at the same point in the noise cycle each time so that synchronous noise sampling occurs. This sampling process, in conjunction with an automated calibration, yields signal noise levels well below the noise level present on the analog reference voltages.

Moisture vapor transport channels for the improved attachment of a medical device to the human body.

PubMed

Cunningham, David D; Lowery, Michael G

2004-06-01

Attachment of a small, medical device to the human body for an extended period of time in an ambulatory setting requires the careful consideration of the physical form of the device and the physiological constraints limiting the time a device will stay on the skin. Factors such as the size of the device, the area of the device available for attachment to the skin, and the occlusive nature of the materials in the device are likely to affect adhesion. Here, plastic acrylic disks, 25 mm in diameter, containing a crisscross pattern of air-filled channels were tested on the forearm and abdomen using a moderately aggressive, unsupported, pressure-sensitive transfer adhesive in a pilot human clinical study. After vigorous exercise, droplets of moisture were observed in the channels followed by evaporation of the droplets over time. Disks without channels remained attached to the skin for about a day and a half, while disks containing 450 microm deep channels remained on the skin about three times longer. Little difference was found when the channel-to-channel spacing was increased from 1.3 to 1.6 mm, however 230 microm deep channels were less effective than 450 microm deep channels. Overall, the moisture vapor transport channels appear capable of reducing the moisture content of the outermost stratum corneum layer of the skin, increasing the strength of the stratum corneum, and increasing the time a device remains attached to the skin. The median trial-to-trial relative standard deviation of 45% observed in the pilot study can be used to design appropriately powered studies for the comparison of different device designs.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor)

2007-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. In some embodiments, network device interfaces associated with different data channels coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

Pedestrian signalization and the risk of pedestrian-motor vehicle collisions in Lima, Peru

PubMed Central

Quistberg, D. Alex; Koepsell, Thomas D.; Boyle, Linda Ng; Miranda, J. Jaime; Johnston, Brian D.; Ebel, Beth E.

2014-01-01

Safe walking environments are essential for protecting pedestrians and promoting physical activity. In Peru, pedestrians comprise of over three-quarters of road fatality victims. Pedestrian signalization plays an important role managing pedestrian and vehicle traffic and may help improve pedestrian safety. We examined the relationship between pedestrian-motor vehicle collisions and the presence of visible traffic signals, pedestrian signals, and signal timing to determine whether these countermeasures improved pedestrian safety. A matched case-control design was used where the units of study were crossing locations. We randomly sampled 97 control-matched collisions (weighted N=1134) at intersections occurring from October, 2010 to January, 2011 in Lima. Each case-control pair was matched on proximity, street classification, and number of lanes. Sites were visited between February, 2011 and September, 2011. Each analysis accounted for sampling weight and matching and was adjusted for vehicle and pedestrian traffic flow, crossing width, and mean vehicle speed. Collisions were more common where a phased pedestrian signal (green or red-lit signal) was present compared to no signalization (odds ratio [OR] 8.88, 95% Confidence Interval [CI] 1.32–59.6). A longer pedestrian-specific signal duration was associated with collision risk (OR 5.31, 95% CI 1.02–9.60 per 15-second interval). Collisions occurred more commonly in the presence of any signalization visible to pedestrians or pedestrian-specific signalization, though these associations were not statistically significant. Signalization efforts were not associated with lower risk for pedestrians; rather, they were associated with an increased risk of pedestrian-vehicle collisions. PMID:24821630

Pedestrian signalization and the risk of pedestrian-motor vehicle collisions in Lima, Peru.

PubMed

Quistberg, D Alex; Koepsell, Thomas D; Boyle, Linda Ng; Miranda, J Jaime; Johnston, Brian D; Ebel, Beth E

2014-09-01

Safe walking environments are essential for protecting pedestrians and promoting physical activity. In Peru, pedestrians comprise over three-quarters of road fatality victims. Pedestrian signalization plays an important role managing pedestrian and vehicle traffic and may help improve pedestrian safety. We examined the relationship between pedestrian-motor vehicle collisions and the presence of visible traffic signals, pedestrian signals, and signal timing to determine whether these countermeasures improved pedestrian safety. A matched case-control design was used where the units of study were crossing locations. We randomly sampled 97 control-matched collisions (weighted N=1134) at intersections occurring from October, 2010 to January, 2011 in Lima. Each case-control pair was matched on proximity, street classification, and number of lanes. Sites were visited between February, 2011 and September, 2011. Each analysis accounted for sampling weight and matching and was adjusted for vehicle and pedestrian traffic flow, crossing width, and mean vehicle speed. Collisions were more common where a phased pedestrian signal (green or red-light signal) was present compared to no signalization (odds ratio [OR] 8.88, 95% Confidence Interval [CI] 1.32-59.6). A longer pedestrian-specific signal duration was associated with collision risk (OR 5.31, 95% CI 1.02-9.60 per 15-s interval). Collisions occurred more commonly in the presence of any signalization visible to pedestrians or pedestrian-specific signalization, though these associations were not statistically significant. Signalization efforts were not associated with lower risk for pedestrians; rather, they were associated with an increased risk of pedestrian-vehicle collisions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relationship between pedestrian headform tests and injury and fatality rates in vehicle-to-pedestrian crashes in the United States.

PubMed

Mueller, Becky; Farmer, Charles; Jermakian, Jessica; Zuby, David

2013-11-01

Pedestrian protection evaluations have been developed to encourage vehicle front-end designs that mitigate the consequences of vehicle-to-pedestrian crashes. The European New Car Assessment Program (Euro NCAP) evaluates pedestrian head protection with impacts against vehicle hood, windshield, and A-pillars. The Global Technical Regulation No. 9 (GTR 9), being evaluated for U.S. regulation, limits head protection evaluations to impacts against vehicle hoods. The objective of this study was to compare results from pedestrian head impact testing to the real-world rates of fatal and incapacitating injuries in U.S. pedestrian crashes. Data from police reported pedestrian crashes in 14 states were used to calculate real-world fatal and in- capacitating injury rates for seven 2002-07 small cars. Rates were 2.17-4.04 per 100 pedestrians struck for fatal injuries and 10.45-15.35 for incapacitating injuries. Euro NCAP style pedestrian headform tests were conducted against windshield, A-pillar, and hoods of the study vehicles. When compared with pedestrian injury rates, the vehicles' Euro NCAP scores, ranging 5-10 points, showed strong negative correlations (-0.6) to injury rates, though none were statistically significant. Data from the headform impacts for each of the study vehicles were used to calculate that vehicle's predicted serious injury risk. The predicted risks from both the Euro NCAP and GTR 9 test zones showed high positive correlations with the pedestrian fatal and incapacitating injury rates, though few were statistically significant. Whether vehicle stiffness is evaluated on all components of vehicle front ends (Euro NCAP) or is limited to hoods (GTR 9), softer vehicle components correspond to a lower risk of fatality.

Pedestrian injury causation study (pedestrian accident typing)

DOT National Transportation Integrated Search

1982-08-01

A new computerized pedestrian accident typing procedure was tested on 1,997 cases from the Pedestrian Injury Causation Study (PICS). Two coding procedures were used to determine the effects of quantity and quality of information on accident typing ac...

Comprehensive study to reduce pedestrian crashes in Florida : [summary].

DOT National Transportation Integrated Search

2013-12-01

Pedestrian crashes are a major safety : concern in Florida, with about one in : every ve traf c fatalities involving a : pedestrian. Recently, researchers at : Florida International University studied : ways to improve pedestrian safety on : F...

Analysis of the mechanism of injury in non-fatal vehicle-to-pedestrian and vehicle-to-bicyclist frontal crashes in Sweden.

PubMed

Öman, Mikael; Fredriksson, Rikard; Bylund, Per-Olof; Björnstig, Ulf

2016-12-01

The aim of this paper is to analyse and compare injuries and injury sources in pedestrian and bicyclist non-fatal real-life frontal passengercar crashes, considering in what way pedestrian injury mitigation systems also might be adequate for bicyclists. Data from 203 non-fatal vehicle-to-pedestrian and vehicle-to-bicyclist crashes from 1997 through 2006 in a city in northern Sweden were analysed by use of the hospitals injury data base in addition to interviews with the injured. In vehicle-to-pedestrian crashes (n = 103) head and neck injuries were in general due to hitting the windscreen frame, while in vehicle-to-bicycle crashes (n = 100) head and neck injuries were typically sustained by ground impact. Abdominal, pelvic and thoracic injuries in pedestrians and thoracic injuries in bicyclists were in general caused by impacting the bonnet. In vehicle-to-pedestrian crashes, energy reducing airbags at critical impact points with low yielding ability on the car, as the bonnet and the windscreen frame, might reduce injuries. As vehicle-to-bicyclist crashes occurred mostly in good lighting conditions and visibility and the ground impact causing almost four times as many injuries as an impact to the different regions of the car, crash avoidance systems as well as separating bicyclists from motor traffic, may contribute to mitigate these injuries.

Network device interface for digitally interfacing data channels to a controller a via network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. In one embodiment, the bus controller transmits messages to the network device interface containing a plurality of bits having a value defined by a transition between first and second states in the bits. The network device interface determines timing of the data sequence of the message and uses the determined timing to communicate with the bus controller.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

2005-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor); Grant, Robert L. (Inventor)

2004-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

Plasma channel optical pumping device and method

DOEpatents

Judd, O.P.

1983-06-28

A device and method are disclosed for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an electrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature blackbody radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device. 5 figs.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor); Konz, Daniel W. (Inventor)

2009-01-01

A communications system and method are provided for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. Network device interfaces associated with different data channels can coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

Light use study for vertical channelization devices

DOT National Transportation Integrated Search

2003-05-01

Although the Manual on Uniform Traffic Control Devices (MUTCD) does not require the use of warning lights on channelization devices, the Arizona Department of Transportation (ADOT) has historically required their use on all traffic control devices us...

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

PubMed Central

Kraemer, John D; Benton, Connor S

2015-01-01

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

Study design and analysis of automobile bumper for pedestrian safety

NASA Astrophysics Data System (ADS)

Kulkarni, Akash; Vora, Rushabh; Ravi, K.

2017-11-01

This paper aims to design and analyse the bumper beam structure, in order to ensure the protection of the pedestrians along with the occupants inside the vehicle. The concern shown towards the pedestrian safety is because, each year about 2,70,000 pedestrians are killed in road accidents that accounts to 22% of the total deaths. From the literature review, it was inferred that the mounting position of bumper and material selection play a crucial role in maximising the pedestrian safety. Hence in this paper, the effects of bumper mounting position and the bumper beam material have been studied, with reference to an explicit dynamic collision involving with a dummy human lower leg set-up. The acceptance of a particular mounting position/material was based on the fact that the maximum stress and deformation induced were less than the yield limits of the human leg form structure (representing the skin, femur and tibia).

Conditions that Influence Drivers' Yielding Behavior for Uncontrolled Crossings

ERIC Educational Resources Information Center

Bourquin, Eugene; Emerson, Robert Wall; Sauerburger, Dona

2011-01-01

Pedestrians with visual impairments need to cross streets where traffic signals and traffic signage are not present. This study examined the influences of several interventions, including a pedestrian's use of a mobility cane, on the behavior of drivers when they were expected to yield to a pedestrian crossing at an uncontrolled crossing.…

Pilot Study: A Pediatric Pedestrian Safety Curriculum for Preschool Children.

PubMed

Bovis, Stephanie E; Harden, Taijha; Hotz, Gillian

2016-01-01

To evaluate and implement the WalkSafe Pre-Kindergarten Pedestrian Safety Curriculum. A quasi-experimental pretest-posttest design without a control group was used to measure children's pedestrian safety knowledge. Knowledge assessments consisting of multiple-choice and short-answer questions were administered pre- and post-curriculum implementation by classroom teachers. Knowledge assessments gauged prekindergarten students' knowledge of pedestrian safety activities prior to safety curriculum implementation and, again, after the students received the curriculum. A total of 605 children (aged 3- to 5-year) from 38 prekindergarten classrooms in 16 randomly selected elementary schools participated in the pedestrian safety education pilot program. Subjects were of multiethnic and diverse backgrounds from the Miami-Dade County Public School District. Of the 605 educated subjects, 454 children completed both pre- and posttests. A statistically significant difference was found between pretest knowledge (M = 5.49, SD = 1.54) and posttest knowledge (M = 6.64, SD = 1.35) assessment scores across all 454 subjects, t(452) = -16.22, p < .001, 95% CI [-1.29, -1.01]. Previous studies have shown that classroom-based training of children as young as 4 years old can yield significant improvements in traffic safety knowledge. The statistical findings of the WalkSafe Pre-Kindergarten Pedestrian Safety Curriculum revealed statistically significant improvements in pedestrian safety knowledge of these young children. Future research efforts will focus on longitudinal behavioral changes in these students and an increase in pedestrian safety behaviors (e.g., utilization of crosswalks or sidewalks).

Autonomous pedestrian localization technique using CMOS camera sensors

NASA Astrophysics Data System (ADS)

Chun, Chanwoo

2014-09-01

We present a pedestrian localization technique that does not need infrastructure. The proposed angle-only measurement method needs specially manufactured shoes. Each shoe has two CMOS cameras and two markers such as LEDs attached on the inward side. The line of sight (LOS) angles towards the two markers on the forward shoe are measured using the two cameras on the other rear shoe. Our simulation results shows that a pedestrian walking down in a shopping mall wearing this device can be accurately guided to the front of a destination store located 100m away, if the floor plan of the mall is available.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted into digital signals and transmitted back to the controller. In one embodiment, the bus controller sends commands and data a defined bit rate, and the network device interface senses this bit rate and sends data back to the bus controller using the defined bit rate.

Crosswalk markings and the risk of pedestrian-motor vehicle collisions in older pedestrians.

PubMed

Koepsell, Thomas; McCloskey, Lon; Wolf, Marsha; Moudon, Anne Vernez; Buchner, David; Kraus, Jess; Patterson, Matthew

2002-11-06

Motor vehicles struck and killed 4739 pedestrians in the United States in the year 2000. Older pedestrians are at especially high risk. To determine whether crosswalk markings at urban intersections influence the risk of injury to older pedestrians. Case-control study in which the units of study were crossing locations. Six cities in Washington and California, with case accrual from February 1995 through January 1999. A total of 282 case sites were street-crossing locations at an intersection where a pedestrian aged 65 years or older had been struck by a motor vehicle while crossing the street; 564 control sites were other nearby crossings that were matched to case sites based on street classification. Trained observers recorded environmental characteristics, vehicular traffic flow and speed, and pedestrian use at each site on the same day of the week and time of day as when the case event had occurred. Risk of pedestrian-motor vehicle collision involving an older pedestrian. After adjusting for pedestrian flow, vehicle flow, crossing length, and signalization, risk of a pedestrian-motor vehicle collision was 2.1-fold greater (95% confidence interval, 1.1-4.0) at sites with a marked crosswalk. Almost all of the excess risk was due to 3.6-fold (95% confidence interval, 1.7-7.9) higher risk associated with marked crosswalks at sites with no traffic signal or stop sign. Crosswalk markings appear associated with increased risk of pedestrian-motor vehicle collision to older pedestrians at sites where no signal or stop sign is present to halt traffic.

Pedestrian injuries due to mobile phone use in public places.

PubMed

Nasar, Jack L; Troyer, Derek

2013-08-01

Research shows that pedestrians, similar to drivers, experience reduced situation awareness, distracted attention and unsafe behavior when talking or texting on their mobile phones. The present study centered on injuries related to mobile phone use among pedestrians. It used data from the US Consumer Product Safety Commission on injuries in hospital emergency rooms from 2004 through 2010. It found that mobile-phone related injuries among pedestrians increased relative to total pedestrian injuries, and paralleled the increase in injuries for drivers, and in 2010 exceeded those for drivers. Pedestrian injuries related to mobile-phone use were higher for males and for people under 31 years old. Using a mobile phone while walking puts pedestrians at risk of accident, injury or death. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of pedestrian age and gender on spatial and temporal distribution of pedestrian crashes.

PubMed

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

2018-01-02

Every year, about 1.24 million people are killed in traffic crashes worldwide and more than 22% of these deaths are pedestrians. Therefore, pedestrian safety has become a significant traffic safety issue worldwide. In order to develop effective and targeted safety programs, the location- and time-specific influences on vehicle-pedestrian crashes must be assessed. The main purpose of this research is to explore the influence of pedestrian age and gender on the temporal and spatial distribution of vehicle-pedestrian crashes to identify the hotspots and hot times. Data for all vehicle-pedestrian crashes on public roadways in the Melbourne metropolitan area from 2004 to 2013 are used in this research. Spatial autocorrelation is applied in examining the vehicle-pedestrian crashes in geographic information systems (GIS) to identify any dependency between time and location of these crashes. Spider plots and kernel density estimation (KDE) are then used to determine the temporal and spatial patterns of vehicle-pedestrian crashes for different age groups and genders. Temporal analysis shows that pedestrian age has a significant influence on the temporal distribution of vehicle-pedestrian crashes. Furthermore, men and women have different crash patterns. In addition, results of the spatial analysis shows that areas with high risk of vehicle-pedestrian crashes can vary during different times of the day for different age groups and genders. For example, for those between ages 18 and 65, most vehicle-pedestrian crashes occur in the central business district (CBD) during the day, but between 7:00 p.m. and 6:00 a.m., crashes among this age group occur mostly around hotels, clubs, and bars. This research reveals that temporal and spatial distributions of vehicle-pedestrian crashes vary for different pedestrian age groups and genders. Therefore, specific safety measures should be in place during high crash times at different locations for different age groups and genders to

Rapid detection and identification of pedestrian impacts using a distributed sensor network

NASA Astrophysics Data System (ADS)

Kim, Andrew C.; Chang, Fu-Kuo

2005-05-01

Pedestrian fatalities from automobile accidents often occur as a result of head injuries suffered from impacts with an automobile front end. Active pedestrian protection systems with proper pedestrian recognition algorithms can protect pedestrians from such head trauma. An investigation was conducted to assess the feasibility of using a network of piezoelectric sensors mounted on the front bumper beam of an automobile to discriminate between impacts with "pedestrian" and "non-pedestrian" objects. This information would be used to activate a safety device (e.g., external airbag or pop-up hood) to provide protection for the vulnerable pedestrian. An analytical foundation for the object-bumper impact problem will be presented, as well as the classical beam impact theory. The mechanical waves that propagate in the structure from an external impact contain a wealth of information about the specifics of a particular impact -- object mass, size, impact speed, etc. -- but most notably the object stiffness, which identifies the impacted object. Using the frequency content of the sensor signals, it can be shown that impacts with a "pedestrian" object of varying size, weight, and speed can be easily differentiated from impacts with other "non-pedestrian" objects. Simulation results will illustrate this phenomenon, and experimental tests will verify the results. A comprehensive series of impact tests were performed for validation, using both a stationary front bumper with a drop-pendulum impactor and a moving car with stationary impact objects. Results from both tests will be presented.

An on-board pedestrian detection and warning system with features of side pedestrian

NASA Astrophysics Data System (ADS)

Cheng, Ruzhong; Zhao, Yong; Wong, ChupChung; Chan, KwokPo; Xu, Jiayao; Wang, Xin'an

2012-01-01

Automotive Active Safety(AAS) is the main branch of intelligence automobile study and pedestrian detection is the key problem of AAS, because it is related with the casualties of most vehicle accidents. For on-board pedestrian detection algorithms, the main problem is to balance efficiency and accuracy to make the on-board system available in real scenes, so an on-board pedestrian detection and warning system with the algorithm considered the features of side pedestrian is proposed. The system includes two modules, pedestrian detecting and warning module. Haar feature and a cascade of stage classifiers trained by Adaboost are first applied, and then HOG feature and SVM classifier are used to refine false positives. To make these time-consuming algorithms available in real-time use, a divide-window method together with operator context scanning(OCS) method are applied to increase efficiency. To merge the velocity information of the automotive, the distance of the detected pedestrian is also obtained, so the system could judge if there is a potential danger for the pedestrian in the front. With a new dataset captured in urban environment with side pedestrians on zebra, the embedded system and its algorithm perform an on-board available result on side pedestrian detection.

Investigating the risk factors associated with pedestrian injury severity in Illinois.

PubMed

Pour-Rouholamin, Mahdi; Zhou, Huaguo

2016-06-01

Pedestrians are known as the most vulnerable road users, which means their needs and safety require specific attention in strategic plans. Given the fact that pedestrians are more prone to higher injury severity levels compared to other road users, this study aims to investigate the risk factors associated with various levels of injury severity that pedestrians experience in Illinois. Ordered-response models are used to analyze single-vehicle, single-pedestrian crash data from 2010 to 2013 in Illinois. As a measure of net change in the effect of significant variables, average direct pseudo-elasticities are calculated that can be further used to prioritize safety countermeasures. A model comparison using AIC and BIC is also provided to compare the performance of the studied ordered-response models. The results recognized many variables associated with severe injuries: older pedestrians (more than 65years old), pedestrians not wearing contrasting clothing, adult drivers (16-24), drunk drivers, time of day (20:00 to 05:00), divided highways, multilane highways, darkness, and heavy vehicles. On the other hand, crossing the street at crosswalks, older drivers (more than 65years old), urban areas, and presence of traffic control devices (signal and sign) are associated with decreased probability of severe injuries. The comparison between three proposed ordered-response models shows that the partial proportional odds (PPO) model outperforms the conventional ordered (proportional odds-PO) model and generalized ordered logit model (GOLM). Based on the findings, stricter rules to address DUI driving is suggested. Educational programs need to focus on older pedestrians given the increasing number of older people in Illinois in the upcoming years. Pedestrians should be educated to use pedestrian crosswalks and contrasting clothing at night. In terms of engineering countermeasures, installation of crosswalks where pedestrian activity is high seems a promising practice

Quantitative analysis of pedestrian safety at uncontrolled multi-lane mid-block crosswalks in China.

PubMed

Zhang, Cunbao; Zhou, Bin; Chen, Guojun; Chen, Feng

2017-11-01

A lot of pedestrian-vehicle crashes at mid-block crosswalks severely threaten pedestrian's safety around the world. The situations are even worse in China due to low yielding rate of vehicles at crosswalks. In order to quantitatively analyze pedestrian's safety at multi-lane mid-block crosswalks, the number of pedestrian-vehicle conflicts was utilized to evaluate pedestrian's accident risk. Five mid-block crosswalks (Wuhan, China) were videoed to collect data of traffic situation and pedestrian-vehicle conflicts, and the quantity and spatial distribution of pedestrian-vehicle conflicts at multi-lane mid-block crosswalk were analyzed according to lane-based post-encroachment time(LPET). Statistical results indicate that conflicts are mainly concentrated in lane3 and lane6. Percentage of conflict of each lane numbered from 1 to 6 respectively are 4.1%, 13.1%, 19.8%, 8.4%, 19.0%, 28.1%. Conflict rate under different crossing strategies are also counted. Moreover, an order probit (OP) model of pedestrian-vehicle conflict analysis (PVCA) was built to find out the contributions corresponding to those factors (such as traffic volume, vehicle speed, pedestrian crossing behavior, pedestrian refuge, etc.) to pedestrian-vehicle conflicts. The results show that: pedestrian refuge have positive effects on pedestrian safety; on the other hand, high vehicle speed, high traffic volume, rolling gap crossing pattern, and larger pedestrian platoon have negative effects on pedestrian safety. Based on our field observation and PVCA model, the number of conflicts will rise by 2% while the traffic volume increases 200 pcu/h; similarly, if the vehicle speed increases 5km/h, the number of conflicts will rise by 12% accordingly. The research results could be used to evaluate pedestrian safety at multi-lane mid-block crosswalks, and useful to improve pedestrian safety by means of pedestrian safety education, pedestrian refuge setting, vehicle speed limiting, and so on. Copyright © 2017

Impact of social and technological distraction on pedestrian crossing behaviour: an observational study

PubMed Central

Thompson, Leah L; Rivara, Frederick P; Ayyagari, Rajiv C; Ebel, Beth E

2013-01-01

Objectives The objective of the present work was to study the impact of technological and social distraction on cautionary behaviours and crossing times in pedestrians. Methods Pedestrians were observed at 20 high-risk intersections during 1 of 3 randomly assigned time windows in 2012. Observers recorded demographic and behavioural information, including use of a mobile device (talking on the phone, text messaging, or listening to music). We examined the association between distraction and crossing behaviours, adjusting for age and gender. All multivariate analyses were conducted with random effect logistic regression (binary outcomes) and random effect linear regression (continuous outcomes), accounting for clustering by site. Results Observers recorded crossing behaviours for 1102 pedestrians. Nearly one-third (29.8%) of all pedestrians performed a distracting activity while crossing. Distractions included listening to music (11.2%), text messaging (7.3%) and using a handheld phone (6.2%). Text messaging, mobile phone use and talking with a companion increased crossing time. Texting pedestrians took 1.87 additional seconds (18.0%) to cross the average intersection (3.4 lanes), compared to undistracted pedestrians. Texting pedestrians were 3.9 times more likely than undistracted pedestrians to display at least 1 unsafe crossing behaviour (disobeying the lights, crossing mid-intersection, or failing to look both ways). Pedestrians listening to music walked more than half a second (0.54) faster across the average intersection than undistracted pedestrians. Conclusions Distracting activity is common among pedestrians, even while crossing intersections. Technological and social distractions increase crossing times, with text messaging associated with the highest risk. Our findings suggest the need for intervention studies to reduce risk of pedestrian injury. PMID:23243104

Effects of mobile Internet use on college student pedestrian injury risk.

PubMed

Byington, Katherine W; Schwebel, David C

2013-03-01

College-age individuals have the highest incidence of pedestrian injuries of any age cohort. One factor that might contribute to elevated pedestrian injuries among this age group is injuries incurred while crossing streets distracted by mobile devices. Examine whether young adult pedestrian safety is compromised while crossing a virtual pedestrian street while distracted using the Internet on a mobile "smartphone." A within-subjects design was implemented with 92 young adults. Participants crossed a virtual pedestrian street 20 times, half the time while undistracted and half while completing an email-driven "scavenger hunt" to answer mundane questions using mobile Internet on their cell phones. Six measures of pedestrian behavior were assessed during crossings. Participants also reported typical patterns of street crossing and mobile Internet use. Participants reported using mobile Internet with great frequency in daily life, including while walking across streets. In the virtual street environment, pedestrian behavior was greatly altered and generally more risky when participants were distracted by Internet use. While distracted, participants waited longer to cross the street (F=42.37), missed more safe opportunities to cross (F=42.63), took longer to initiate crossing when a safe gap was available (F=53.03), looked left and right less often (F=124.68), spent more time looking away from the road (F=1959.78), and were more likely to be hit or almost hit by an oncoming vehicle (F=29.54; all ps<0.01). Results were retained after controlling for randomized order; participant gender, age, and ethnicity; and both pedestrian habits and mobile Internet experience. Pedestrian behavior was influenced, and generally considerably riskier, when participants were simultaneously using mobile Internet and crossing the street than when crossing the street with no distraction. This finding reinforces the need for increased awareness concerning the risks of distracted pedestrian

Effects of Mobile Internet Use On College Student Pedestrian Injury Risk

PubMed Central

Byington, Katherine W.; Schwebel, David C.

2012-01-01

Background College-age individuals have the highest incidence of pedestrian injuries of any age cohort. One factor that might contribute to elevated pedestrian injuries among this age group is injuries incurred while crossing streets distracted by mobile devices. Objectives Examine whether young adult pedestrian safety is compromised while crossing a virtual pedestrian street while distracted using the internet on a mobile “smartphone.” Method A within-subjects design was implemented with 92 young adults. Participants crossed a virtual pedestrian street 20 times, half the time while undistracted and half while completing an email-driven “scavenger hunt” to answer mundane questions using mobile internet on their cell phones. Six measures of pedestrian behavior were assessed during crossings. Participants also reported typical patterns of street crossing and mobile internet use. Results Participants reported using mobile internet with great frequency in daily life, including while walking across streets. In the virtual street environment, pedestrian behavior was greatly altered and generally more risky when participants were distracted by internet use. While distracted, participants waited longer to cross the street (F = 42.37), missed more safe opportunities to cross (F = 42.63), took longer to initiate crossing when a safe gap was available (F = 53.03), looked left and right less often (F = 124.68), spent more time looking away from the road (F = 1959.78), and were more likely to be hit or almost hit by an oncoming vehicle (F = 29.54; all ps< 0.01). Results were retained after controlling for randomized order; participant gender, age, and ethnicity; and both pedestrian habits and mobile internet experience. Conclusion Pedestrian behavior was influenced, and generally considerably riskier, when participants were simultaneously using mobile internet and crossing the street than when crossing the street with no distraction. This finding reinforces the need for

Impact of access management practices to pedestrian safety.

DOT National Transportation Integrated Search

2017-03-31

This study focused on the impact of access management practices to the safety of pedestrians. Some : of the access management practices considered to impact pedestrian safety included limiting direct : access to and from major streets, locating signa...

Device-independent tests of quantum channels

NASA Astrophysics Data System (ADS)

Dall'Arno, Michele; Brandsen, Sarah; Buscemi, Francesco

2017-03-01

We develop a device-independent framework for testing quantum channels. That is, we falsify a hypothesis about a quantum channel based only on an observed set of input-output correlations. Formally, the problem consists of characterizing the set of input-output correlations compatible with any arbitrary given quantum channel. For binary (i.e. two input symbols, two output symbols) correlations, we show that extremal correlations are always achieved by orthogonal encodings and measurements, irrespective of whether or not the channel preserves commutativity. We further provide a full, closed-form characterization of the sets of binary correlations in the case of: (i) any dihedrally covariant qubit channel (such as any Pauli and amplitude-damping channels) and (ii) any universally-covariant commutativity-preserving channel in an arbitrary dimension (such as any erasure, depolarizing, universal cloning and universal transposition channels).

Device-independent tests of quantum channels.

PubMed

Dall'Arno, Michele; Brandsen, Sarah; Buscemi, Francesco

2017-03-01

We develop a device-independent framework for testing quantum channels. That is, we falsify a hypothesis about a quantum channel based only on an observed set of input-output correlations. Formally, the problem consists of characterizing the set of input-output correlations compatible with any arbitrary given quantum channel. For binary (i.e. two input symbols, two output symbols) correlations, we show that extremal correlations are always achieved by orthogonal encodings and measurements, irrespective of whether or not the channel preserves commutativity. We further provide a full, closed-form characterization of the sets of binary correlations in the case of: (i) any dihedrally covariant qubit channel (such as any Pauli and amplitude-damping channels) and (ii) any universally-covariant commutativity-preserving channel in an arbitrary dimension (such as any erasure, depolarizing, universal cloning and universal transposition channels).

Comprehensive study to reduce pedestrian crashes in Florida.

DOT National Transportation Integrated Search

2013-12-01

Pedestrian crashes are a major traffic safety concern in Florida. This project aims to improve pedestrian safety on : Floridas state roads by identifying crash patterns and contributing factors at both the statewide and site-specific : level and p...

Evaluating Countermeasures to Improve Pedestrian and Bicycle Safety

DOT National Transportation Integrated Search

2018-11-01

Pedestrian crashes have reached an alarming level in the U.S. Different factors could contribute to the occurrence of these crashes at an intersection, including driver errors, the type of maneuver, and pedestrian behaviors. All these factors highlig...

Pedestrian safety action plan.

DOT National Transportation Integrated Search

2009-06-01

In 2005, Arizona ranked 5th among states in pedestrian fatalities per 100,000 residents, with 164 : pedestrian fatalities on Arizonas roadwaysa nearly 30 percent increase from 2003 levels. To reduce : the number of pedestrian crashes in Arizona...

A rapid method for identifying and characterizing structural impacts using distributed sensors: An application for automotive pedestrian protection

NASA Astrophysics Data System (ADS)

Kim, Andrew C.

This research is motivated by recent activity to improve automotive safety, especially for pedestrians. In many parts of the world today, injuries and fatalities from road accidents are a significant problem. Safety features such as seat restraints and air bags provide considerable levels of protection for car occupants; however, no such protective measures currently exist for pedestrians. Drawing upon the success and effectiveness of occupant air bag systems, current research aims to develop similar devices for pedestrians. These active pedestrian protection systems deploy a safety feature such as an external air bag when a pedestrian is hit by a vehicle. Contact with the front bumper induces a body rotation that may result in a violent head collision. The deployable safety device provides a cushioning surface for the vulnerable pedestrian during impact. The challenge of such a system is an effective sensory unit that can rapidly and correctly discriminate pedestrian impacts from non-pedestrian ones. The fast kinematics of the automobile-pedestrian impact leaves a minimal amount of time for signal processing and computation. This research study focuses on a discrimination scheme that satisfies both the time and accuracy requirements for a proposed sensory system for pedestrian protection. A unique methodology was developed to identify structural impacts using dominant frequency features extracted from sensory data. Contact sensors mounted on the front bumper of an automobile measure the strain response from an impact event. The dominant frequencies obtained from these sensor signals are greatly influenced by the impact object's properties and can be used to discriminate between different objects. Extensive tests were conducted to gather sensor data and validate the proposed methodology and impact discrimination algorithm. Results of the impact tests indicate that the approach is sound, and the sensory system effectively identifies "pedestrian" impacts within a

Coarse-to-fine deep neural network for fast pedestrian detection

NASA Astrophysics Data System (ADS)

Li, Yaobin; Yang, Xinmei; Cao, Lijun

2017-11-01

Pedestrian detection belongs to a category of object detection is a key issue in the field of video surveillance and automatic driving. Although recent object detection methods, such as Fast/Faster RCNN, have achieved excellent performance, it is difficult to meet real-time requirements and limits the application in real scenarios. A coarse-to-fine deep neural network for fast pedestrian detection is proposed in this paper. Two-stage approach is presented to realize fine trade-off between accuracy and speed. In the coarse stage, we train a fast deep convolution neural network to generate most pedestrian candidates at the cost of a number of false positives. The detector can cover the majority of scales, sizes, and occlusions of pedestrians. After that, a classification network is introduced to refine the pedestrian candidates generated from the previous stage. Refining through classification network, most of false detections will be excluded easily and the final pedestrian predictions with bounding box and confidence score are produced. Competitive results have been achieved on INRIA dataset in terms of accuracy, especially the method can achieve real-time detection that is faster than the previous leading methods. The effectiveness of coarse-to-fine approach to detect pedestrians is verified, and the accuracy and stability are also improved.

[Pedestrian head injury biomechanics and damage mechanism. Pedestrian protection automotive regulation assessment].

PubMed

Arregui-Dalmases, Carlos; Rebollo-Soria, M Carmen; Sanchez-Molina, David; Velazquez-Ameijide, Juan; Teijeira Alvarez

Pedestrian-vehicle collisions are a leading cause of death among motor vehicle accidents. Recently, pedestrian injury research has been increased, mostly due to the implementation of European and Japanese regulations. This research presents an analysis of the main head injury vehicle sources and injury mechanisms observed in the field, posteriorly the data are compared with the current pedestrian regulations. The analysis has been performed through an epidemiologic transversal and descriptive study, using the Pedestrian Crash Data Study (PCDS) involving 552 pedestrians, sustaining a total of 4.500 documented injuries. According to this research, the hood surface is responsible for only 15,1% of all the head injuries. On the other hand, the windshield glazing is responsible for 41,8%. In case of sedan vehicles the head impact location exceeds what is expected in the current regulation, and therefore no countermeasures are applied. From all the head injuries sustained by the pedestrians just 20% have the linear acceleration as isolated injury mechanism, 40% of the injuries are due to rotational acceleration. In this research, the importance of the rotational acceleration as injury mechanism, in case of pedestrian-vehicle collision is highlighted. In the current pedestrian regulation just the linear acceleration is addressed in the main injury criteria used for head injury prediction. Copyright © 2016 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

Risky behaviors associated with pediatric pedestrians and bicyclists struck by motor vehicles.

PubMed

Glass, Nina E; Frangos, Spiros G; Simon, Ronald J; Bholat, Omar S; Todd, S Rob; Wilson, Chad; Jacko, Sally; Slaughter, Dekeya; Foltin, George; Levine, Deborah A

2014-06-01

Road safety constitutes a crisis with important health and economic impacts. In 2010, 11,000 pedestrians and 3500 bicyclists were injured by motor vehicles in New York City (NYC). Motor vehicle injuries represent the second leading cause of injury-related deaths in NYC children aged 5 to 14 years. To better target injury prevention strategies, we evaluated demographics, behaviors, environmental factors, injuries, and outcomes of pediatric pedestrians and bicyclists struck by motor vehicles in NYC. Pediatric data were extracted from a prospectively collected database of pedestrians and bicyclists struck by motor vehicles and treated at a level I regional trauma center between December 2008 and June 2011. Patients, guardians, and first responders were interviewed and medical records were reviewed. Institutional review board approval was granted and verbal consent was obtained. Of the 1457 patients, 168 (12%) were younger than 18 years. Compared with injured adults, children were more likely to be in male sex (69% vs 53%), to have minor injuries (83% vs 73% for injury severity scores of <9), and to be discharged without admission (69% vs 67%). Midblock crossings were more common in children pedestrians than in adults (37% vs 19%), often despite supervision (48%). Electronic device use among teenagers aged 13 to 17 years was nearly 3 times that of adults (28% vs 11%). Risky behaviors are common among pediatric pedestrians and bicyclists injured by motor vehicles. Road safety education and prevention strategies must stress compliance with traffic laws, readdress the importance of supervision, and reinforce avoidance of common distractors including electronic devices.

Measuring pedestrian volumes and conflicts. Volume 1, Pedestrian volume sampling

DOT National Transportation Integrated Search

1987-12-01

This final report presents the findings, conclusions, and recommendations of the study conducted to develop a model to predict pedestrian volumes using small sampling schemes. This research produced four pedestrian volume prediction models (i.e., 1-,...

Teaching Pedestrian Skills to Individuals with Developmental Disabilities

ERIC Educational Resources Information Center

Batu, Sema; Ergenekon, Yasemin; Erbas, Dilek; Akmanoglu, Nurgul

2004-01-01

The purpose of the present study was to examine the effectiveness of most to least prompting on teaching pedestrian skills to individuals with developmental disabilities. Five individuals with developmental disabilities were taught three different pedestrian skills, all related to crossing the streets, using simulation activities on a road model…

Safer passenger car front shapes for pedestrians: A computational approach to reduce overall pedestrian injury risk in realistic impact scenarios.

PubMed

Li, Guibing; Yang, Jikuang; Simms, Ciaran

2017-03-01

Vehicle front shape has a significant influence on pedestrian injuries and the optimal design for overall pedestrian protection remains an elusive goal, especially considering the variability of vehicle-to-pedestrian accident scenarios. Therefore this study aims to develop and evaluate an efficient framework for vehicle front shape optimization for pedestrian protection accounting for the broad range of real world impact scenarios and their distributions in recent accident data. Firstly, a framework for vehicle front shape optimization for pedestrian protection was developed based on coupling of multi-body simulations and a genetic algorithm. This framework was then applied for optimizing passenger car front shape for pedestrian protection, and its predictions were evaluated using accident data and kinematic analyses. The results indicate that the optimization shows a good convergence and predictions of the optimization framework are corroborated when compared to the available accident data, and the optimization framework can distinguish 'good' and 'poor' vehicle front shapes for pedestrian safety. Thus, it is feasible and reliable to use the optimization framework for vehicle front shape optimization for reducing overall pedestrian injury risk. The results also show the importance of considering the broad range of impact scenarios in vehicle front shape optimization. A safe passenger car for overall pedestrian protection should have a wide and flat bumper (covering pedestrians' legs from the lower leg up to the shaft of the upper leg with generally even contacts), a bonnet leading edge height around 750mm, a short bonnet (<800mm) with a shallow or steep angle (either >17° or <12°) and a shallow windscreen (≤30°). Sensitivity studies based on simulations at the population level indicate that the demands for a safe passenger car front shape for head and leg protection are generally consistent, but partially conflict with pelvis protection. In particular, both

Real-Time pedestrian detection : layered object recognition system for pedestrian collision sensing.

DOT National Transportation Integrated Search

2010-01-01

In 2005 alone, 64,000 pedestrians were injured and 4,882 were killed in the United States, with pedestrians accounting for 11 percent of all traffic fatalities and 2 percent of injuries. The focus of "Layered Object Recognition System for Pedestrian ...

Detection of the toughest: Pedestrian injury risk as a smooth function of age.

PubMed

Niebuhr, Tobias; Junge, Mirko

2017-07-04

Though it is common to refer to age-specific groups (e.g., children, adults, elderly), smooth trends conditional on age are mainly ignored in the literature. The present study examines the pedestrian injury risk in full-frontal pedestrian-to-passenger car accidents and incorporates age-in addition to collision speed and injury severity-as a plug-in parameter. Recent work introduced a model for pedestrian injury risk functions using explicit formulae with easily interpretable model parameters. This model is expanded by pedestrian age as another model parameter. Using the German In-Depth Accident Study (GIDAS) to obtain age-specific risk proportions, the model parameters are fitted to the raw data and then smoothed by broken-line regression. The approach supplies explicit probabilities for pedestrian injury risk conditional on pedestrian age, collision speed, and injury severity under investigation. All results yield consistency to each other in the sense that risks for more severe injuries are less probable than those for less severe injuries. As a side product, the approach indicates specific ages at which the risk behavior fundamentally changes. These threshold values can be interpreted as the most robust ages for pedestrians. The obtained age-wise risk functions can be aggregated and adapted to any population. The presented approach is formulated in such general terms that in can be directly used for other data sets or additional parameters; for example, the pedestrian's sex. Thus far, no other study using age as a plug-in parameter can be found.

Dynamical coupled-channels study of {pi}N{yields}{pi}{pi}N reactions

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

Kamano, H.; Julia-Diaz, B.; Department d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona E-08028 Barcelona

As a step toward performing a complete coupled-channels analysis of the world data of {pi}N,{gamma}*N{yields}{pi}N,{eta}N,{pi}{pi}N reactions, the {pi}N{yields}{pi}{pi}N reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C 76, 065201 (2007). The channels included are {pi}N,{eta}N, and {pi}{pi}N which has {pi}{delta},{rho}N, and {sigma}N resonant components. The nonresonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16 bare excited nucleon (N*) states that are dressed by the nonresonant interactions as constrained by the unitarity condition. The data of total cross sectionsmore » and {pi}N and {pi}{pi} invariant mass distributions of {pi}{sup +}p{yields}{pi}{sup +}{pi}{sup +}n,{pi}{sup +}{pi}{sup 0}p and {pi}{sup -}p{yields}{pi}{sup +}{pi}{sup -}n,{pi}{sup -}{pi}{sup 0}p,{pi}{sup 0}{pi}{sup 0}n reactions from threshold to the invariant mass W=2 GeV can be described to a very large extent. We show the importance of the coupled-channels effects and the strong interference among the contributions from the {pi}{delta},{sigma}N, and {rho}N channels. The large interference between the resonant and nonresonant amplitudes is also demonstrated. Possible future developments are discussed.« less

Effect of cell phone distraction on pediatric pedestrian injury risk.

PubMed

Stavrinos, Despina; Byington, Katherine W; Schwebel, David C

2009-02-01

Early adolescents are using cell phones with increasing frequency. Cell phones are known to distract motor vehicle drivers to the point that their safety is jeopardized, but it is unclear if cell phones might also distract child pedestrians. This study was designed to examine the influence of talking on a cell phone for pediatric pedestrian injury risk. Seventy-seven children aged 10 to 11 years old completed simulated road crossings in an immersive, interactive virtual pedestrian environment. In a within-subjects design, children crossed the virtual street 6 times while undistracted and 6 times while distracted by a cell phone conversation with an unfamiliar research assistant. Participants also completed several other experimental tasks hypothesized to predict the impact of distraction while crossing the street and talking on a cell phone. Children's pedestrian safety was compromised when distracted by a cell phone conversation. While distracted, children were less attentive to traffic; left less safe time between their crossing and the next arriving vehicle; experienced more collisions and close calls with oncoming traffic; and waited longer before beginning to cross the street. Analyses testing experience using a cell phone and experience as a pedestrian yielded few significant results, suggesting that distraction on the cell phone might affect children's pedestrian safety no matter what their experience level. There was some indication that younger children and children who are less attentive and more oppositional may be slightly more susceptible to distraction while talking on the cell phone than older, more attentive, and less oppositional children. Our results suggest that cell phones distract preadolescent children while crossing streets.

Application of demographic analysis to pedestrian safety : final report.

DOT National Transportation Integrated Search

2017-04-01

In recent years, many departments of transportation in the US have invested additional resources to enhance : pedestrian safety. However, there is still a need to effectively and systematically address the pedestrian experience : in low-income areas....

Two-ply channels for faster wicking in paper-based microfluidic devices.

PubMed

Camplisson, Conor K; Schilling, Kevin M; Pedrotti, William L; Stone, Howard A; Martinez, Andres W

2015-12-07

This article describes the development of porous two-ply channels for paper-based microfluidic devices that wick fluids significantly faster than conventional, porous, single-ply channels. The two-ply channels were made by stacking two single-ply channels on top of each other and were fabricated entirely out of paper, wax and toner using two commercially available printers, a convection oven and a thermal laminator. The wicking in paper-based channels was studied and modeled using a modified Lucas-Washburn equation to account for the effect of evaporation, and a paper-based titration device incorporating two-ply channels was demonstrated.

Traffic safety facts 1998 : pedestrians

DOT National Transportation Integrated Search

1999-01-01

In 1998, 5,220 pedestrians were killed in traffic crashes in the United States - a decrease of 24 percent from the 6,870 pedestrians killed in 1988. On average, a pedestrian is killed in a traffic crash every 101 minutes. There were 69,000 pedestrian...

Traffic safety facts 1999 : pedestrians

DOT National Transportation Integrated Search

2000-01-01

In 1999, 4,906 pedestrians were killed in traffic crashes in the United States - a decrease of 25 percent from the 6,556 pedestrians killed in 1989. On average, a pedestrian is killed in a traffic crash every 107 minutes. There were 85,000 pedestrian...

Traffic safety facts 2000 : pedestrians

DOT National Transportation Integrated Search

2001-01-01

In 2000, 4,739 pedestrians were killed in traffic crashes in the United States - a decrease of 27 percent from the 6,482 pedestrians killed in 1990. On average, a pedestrian is killed in a traffic crash every 111 minutes. There were 78,000 pedestrian...

Traffic safety facts 1998 : pedestrian

DOT National Transportation Integrated Search

1998-01-01

In 1998, 5,220 pedestrians were killed in traffic crashes in the United States - a decrease of 24% from the 6,870 pedestrians killed in 1988. On average, a pedestrian is killed in a traffic crash every 101 minutes. There were 69,000 pedestrians injur...

Pedestrian temporal and spatial gap acceptance at mid-block street crossing in developing world.

PubMed

Pawar, Digvijay S; Patil, Gopal R

2015-02-01

Most of the midblock pedestrian crossings on urban roads in India are uncontrolled; wherein the high degree of discretion in pedestrians' behavior while crossing the traffic stream, has made the situation complex to analyze. Vehicles do not yield to pedestrians, even though the traffic laws give priority to pedestrians over motorized vehicles at unsignalized pedestrian crossings. Therefore, a pedestrian has to decide if an available gap is safe or not for crossing. This paper aims to investigate pedestrian temporal and spatial gap acceptance for midblock street crossings. Field data were collected using video camera at two midblock pedestrian crossings. The data extraction in laboratory resulted in 1107 pedestrian gaps. Available gaps, pedestrians' decision, traffic volume, etc. were extracted from the videos. While crossing a road with multiple lanes, rolling gap acceptance behavior was observed. Using binary logit analysis, six utility models were developed, three each for temporal and spatial gaps. The 50th percentile temporal and spatial gaps ranged from 4.1 to 4.8s and 67 to 79 m respectively, whereas the 85th percentile temporal and spatial gaps ranged from 5 to 5.8s and 82 to 95 m respectively. These gap values were smaller than that reported in the studies in developed countries. The speed of conflicting vehicle was found to be significant in spatial gap but not in temporal gap acceptance. The gap acceptance decision was also found to be affected by the type of conflicting vehicles. The insights from this study can be used for the safety and performance evaluation of uncontrolled midblock street crossings in developing countries. Copyright © 2014 Elsevier Ltd and National Safety Council. All rights reserved.

Spatiotemporal approaches to analyzing pedestrian fatalities: the case of Cali, Colombia.

PubMed

Fox, Lani; Serre, Marc L; Lippmann, Steven J; Rodríguez, Daniel A; Bangdiwala, Shrikant I; Gutiérrez, María Isabel; Escobar, Guido; Villaveces, Andrés

2015-01-01

Injuries among pedestrians are a major public health concern in Colombian cities such as Cali. This is one of the first studies in Latin America to apply Bayesian maximum entropy (BME) methods to visualize and produce fine-scale, highly accurate estimates of citywide pedestrian fatalities. The purpose of this study is to determine the BME method that best estimates pedestrian mortality rates and reduces statistical noise. We further utilized BME methods to identify and differentiate spatial patterns and persistent versus transient pedestrian mortality hotspots. In this multiyear study, geocoded pedestrian mortality data from the Cali Injury Surveillance System (2008 to 2010) and census data were utilized to accurately visualize and estimate pedestrian fatalities. We investigated the effects of temporal and spatial scales, addressing issues arising from the rarity of pedestrian fatality events using 3 BME methods (simple kriging, Poisson kriging, and uniform model Bayesian maximum entropy). To reduce statistical noise while retaining a fine spatial and temporal scale, data were aggregated over 9-month incidence periods and censal sectors. Based on a cross-validation of BME methods, Poisson kriging was selected as the best BME method. Finally, the spatiotemporal and urban built environment characteristics of Cali pedestrian mortality hotspots were linked to intervention measures provided in Mead et al.'s (2014) pedestrian mortality review. The BME space-time analysis in Cali resulted in maps displaying hotspots of high pedestrian fatalities extending over small areas with radii of 0.25 to 1.1 km and temporal durations of 1 month to 3 years. Mapping the spatiotemporal distribution of pedestrian mortality rates identified high-priority areas for prevention strategies. The BME results allow us to identify possible intervention strategies according to the persistence and built environment of the hotspot; for example, through enforcement or long-term environmental

Finding strategies to improve pedestrian safety in rural areas

DOT National Transportation Integrated Search

2001-10-11

This paper is based upon an analysis of collisions involving pedestrians in rural areas and proposes ways of preventing them. Pedestrian and vehicle volumes were counted and crash numbers predicted and compared to outcomes in varying environments. It...

Pedestrian Safety in Road Traffic in Poland

NASA Astrophysics Data System (ADS)

Budzynski, Marcin; Jamroz, Kazimierz; Mackun, Tomasz

2017-10-01

Every third road accident in Poland involves a pedestrian as a participant or, most of the time, a casualty. Pedestrian accidents are usually the result of complex situations and the outcome of a number of factors related to driver and pedestrian behaviour and road infrastructure. Safety depends largely on how well the traffic condition is perceived and on visibility in traffic. The paper presents the results of analyses of methodologies for systematic studies of pedestrian behaviour and pedestrian-driver relations. The effects of the location of the site, type of cross-section and other selected parameters on pedestrian and driver behaviour are demonstrated. The analyses showed that pedestrians are most often put at risk by too long pedestrian crossings, vehicles going too fast around pedestrian crossings, lack of proper sight distance and poorly lit or unlit pedestrian crossings. The reason for such defective infrastructure is that planners, designers, contractors and maintenance services are not receiving any support from design, marking and maintenance regulations for pedestrian traffic. In addition, the Road Traffic Law is not restrictive enough when it comes to drivers’ obligations towards pedestrian safety. Polish design regulations allow long pedestrian crossings up to four lanes in one direction or three lanes in two directions irrespective of traffic control and speed limits. Pedestrian crossings should be kept at a maximum of three lanes. There is nothing in the design regulations about the required driver-pedestrian sight distance. Neither does the Road Traffic Law help engineers with that. It is legal to park vehicles within 10 m of a pedestrian crossing which does not guarantee the necessary sight distance. Drivers must be able to see a pedestrian waiting or stepping onto the crossing from a distance that will help them come to a stop safely. It is safer to follow the principle of providing adequate pedestrian sight distance. Recommendations for

Pedestrian/bicyclist warning devices and signs at CTA rail-highway grade crossings.

DOT National Transportation Integrated Search

2015-12-14

In the last 10 years, contrary to a decrease in the number of train-vehicle collisions at highway-rail grade crossings, the number of pedestrian and bicycle fatalities at highway-rail grade crossings has increased. The objective of this study was to ...

Studies to determine the effectiveness of longitudinal channelizing devices in work zones.

DOT National Transportation Integrated Search

2011-01-01

This report describes the methodology and results of analyses performed to determine whether the following longitudinal : channelizing device (LCD) applications improve the traffic safety and operations of work zones relative to the use of standard :...

Dutch pedestrian safety research review

DOT National Transportation Integrated Search

1999-12-01

This report is one in a series of pedestrian safety synthesis reports prepared for the Federal Highway Administration to document pedestrian safety in other countries. This report reviews recent pedestrian safety research in the Netherlands. It addre...

Evaluating the effect of advance yield markings and symbolic signs on vehicle-pedestrian conflicts at marked midblock crosswalks across multilane roads.

DOT National Transportation Integrated Search

2016-02-01

The Commonwealth of Massachusetts has made walkable communities a priority. Pedestrian safety is key to the success of : this objective. Pedestrians are at high risk when traversing unsignalized, marked crosswalks located either midblock or at Tinter...

Canadian research on pedestrian safety

DOT National Transportation Integrated Search

1999-12-01

This report is one in a series of pedestrian safety synthesis reports prepared for the Federal Highway Administration to document pedestrian safety in other countries. This report reviews Canadian research in six areas of pedestrian safety: (1) Inter...

Pedestrians. Traffic Safety Facts, 2000.

ERIC Educational Resources Information Center

National Highway Traffic Safety Administration (DOT), Washington, DC.

This document provides statistical information on U.S. traffic accidents involving pedestrians. Data tables include: (1) trends in pedestrian and total traffic fatalities, 1990-2000; (2) pedestrians killed and injured, by age group, 2000; (3) non-occupant traffic fatalities, 1990-2000; (4) pedestrian fatalities, by time of day and day of week,…

Traffic Safety Facts, 2001: Pedestrians.

ERIC Educational Resources Information Center

National Highway Traffic Safety Administration (DOT), Washington, DC.

This document provides statistical information on U.S. traffic accidents involving pedestrians. Data tables include: (1) trends in pedestrian and total traffic fatalities, 1991-2001; (2) pedestrians killed and injured, by age group, 2001; (3) non-occupant traffic fatalities, 1991-2001; (4) pedestrian fatalities, by time of day and day of week,…

Evaluating the Effect of Advance Yield Markings and Symbolic Signs on Vehicle-Pedestrian Conflicts at Marked Midblock Crosswalks across Multilane Roads

DOT National Transportation Integrated Search

2016-02-01

The Commonwealth of Massachusetts has made walkable communities a priority. Pedestrian safety is key to the success of this objective. Pedestrians are at high risk when traversing unsignalized, marked crosswalks located either midblock or at T inters...

Development of pedestrian safety based warrants for permissive left-turn control

DOT National Transportation Integrated Search

2010-12-01

At the intersections with permissive only signal control, pedestrians will move at the permissive phase with the parallel through vehicular movement and left-turn vehicles, the left-turn vehicles have to yield to both opposing through vehicles and pe...

[Use and non-use of pedestrian bridges in Mexico City. The pedestrian perspective].

PubMed

Hidalgo-Solórzano, Elisa; Campuzano-Rincón, Julio; Rodríguez-Hernández, Jorge M; Chias-Becerril, Luis; Reséndiz-López, Héctor; Sánchez-Restrepo, Harvey; Baranda-Sepúlveda, Bernardo; Franco-Arias, Claudia; Híjar, Martha

2010-01-01

To analyze the motives for using and not using pedestrian bridges (PB). A cross-sectional survey was conducted of a sample of pedestrian users and non-users of PB; a logistic regression model was used to analyze the motives for use and non-use. The prevalence of non-use was 50.5 % of 813 surveyed pedestrians; the principal reason to use a PB was safety, and not to use it was "laziness". There were significant differences when analyzing the reason of non-use in the age groups 19 to 36 years, adjusted for education and physical characteristics of the PB ([aOR=1.7; 95 % CI=1.06-2.86] and [ORa.1.9; 95 % CI=1.14-3.33], respectively). The results of this study allow us to identify important aspects to consider--from the perspective of the pedestrians--when constructing new PB and improving existing PB to increase use in areas with a high risk of pedestrian injuries.

Simulation of devices mobility to estimate wireless channel quality metrics in 5G networks

NASA Astrophysics Data System (ADS)

Orlov, Yu.; Fedorov, S.; Samuylov, A.; Gaidamaka, Yu.; Molchanov, D.

2017-07-01

The problem of channel quality estimation for devices in a wireless 5G network is formulated. As a performance metrics of interest we choose the signal-to-interference-plus-noise ratio, which depends essentially on the distance between the communicating devices. A model with a plurality of moving devices in a bounded three-dimensional space and a simulation algorithm to determine the distances between the devices for a given motion model are devised.

An evidence based method to calculate pedestrian crossing speeds in vehicle collisions (PCSC).

PubMed

Bastien, C; Wellings, R; Burnett, B

2018-06-07

Pedestrian accident reconstruction is necessary to establish cause of death, i.e. establishing vehicle collision speed as well as circumstances leading to the pedestrian being impacted and determining culpability of those involved for subsequent court enquiry. Understanding the complexity of the pedestrian attitude during an accident investigation is necessary to ascertain the causes leading to the tragedy. A generic new method, named Pedestrian Crossing Speed Calculator (PCSC), based on vector algebra, is proposed to compute the pedestrian crossing speed at the moment of impact. PCSC uses vehicle damage and pedestrian anthropometric dimensions to establish a combination of head projection angles against the windscreen; this angle is then compared against the combined velocities angle created from the vehicle and the pedestrian crossing speed at the time of impact. This method has been verified using one accident fatality case in which the exact vehicle and pedestrian crossing speeds were known from Police forensic video analysis. PCSC was then applied on two other accident scenarios and correctly corroborated with the witness statements regarding the pedestrians crossing behaviours. The implications of PCSC could be significant once fully validated against further future accident data, as this method is reversible, allowing the computation of vehicle impact velocity from pedestrian crossing speed as well as verifying witness accounts. Copyright © 2018 Elsevier Ltd. All rights reserved.

An entropy model to measure heterogeneity of pedestrian crowds using self-propelled agents

NASA Astrophysics Data System (ADS)

Rangel-Huerta, A.; Ballinas-Hernández, A. L.; Muñoz-Meléndez, A.

2017-05-01

An entropy model to characterize the heterogeneity of a pedestrian crowd in a counter-flow corridor is presented. Pedestrians are modeled as self-propelled autonomous agents that are able to perform maneuvers to avoid collisions based on a set of simple rules of perception and action. An observer can determine a probability distribution function of the displayed behavior of pedestrians based only on external information. Three types of pedestrian are modeled, relaxed, standard and hurried pedestrians depending on their preferences of turn and non-turn when walking. Thus, using these types of pedestrians two crowds can be simulated: homogeneous and heterogeneous crowds. Heterogeneity is measured in this research based on the entropy in function of time. For that, the entropy of a homogeneous crowd comprising standard pedestrians is used as reference. A number of simulations to measure entropy of pedestrian crowds were conducted by varying different combinations of types of pedestrians, initial simulation conditions of macroscopic flow, as well as density of the crowd. Results from these simulations show that our entropy model is sensitive enough to capture the effect of both the initial simulation conditions about the spatial distribution of pedestrians in a corridor, and the composition of a crowd. Also, a relevant finding is that entropy in function of density presents a phase transition in the critical region.

On-Board Detection of Pedestrian Intentions

PubMed Central

Fang, Zhijie; Vázquez, David

2017-01-01

Avoiding vehicle-to-pedestrian crashes is a critical requirement for nowadays advanced driver assistant systems (ADAS) and future self-driving vehicles. Accordingly, detecting pedestrians from raw sensor data has a history of more than 15 years of research, with vision playing a central role. During the last years, deep learning has boosted the accuracy of image-based pedestrian detectors. However, detection is just the first step towards answering the core question, namely is the vehicle going to crash with a pedestrian provided preventive actions are not taken? Therefore, knowing as soon as possible if a detected pedestrian has the intention of crossing the road ahead of the vehicle is essential for performing safe and comfortable maneuvers that prevent a crash. However, compared to pedestrian detection, there is relatively little literature on detecting pedestrian intentions. This paper aims to contribute along this line by presenting a new vision-based approach which analyzes the pose of a pedestrian along several frames to determine if he or she is going to enter the road or not. We present experiments showing 750 ms of anticipation for pedestrians crossing the road, which at a typical urban driving speed of 50 km/h can provide 15 additional meters (compared to a pure pedestrian detector) for vehicle automatic reactions or to warn the driver. Moreover, in contrast with state-of-the-art methods, our approach is monocular, neither requiring stereo nor optical flow information. PMID:28946632

Alpha Channeling in Open-System Magnetic Devices

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

Fisch, Nathaniel

The Grant DE-SC0000736, Alpha Channeling in Open-System Magnetic Devices, is a continuation of the Grant DE-FG02-06ER54851, Alpha Channeling in Mirror Machines. In publications funded by DE-SC0000736, the grant DE-FG02-06ER54851 was actually credited. The key results obtained under Grant DE-SC0000736, Alpha Channeling in Open-System Magnetic Devices, appear in a series of publications. The earlier effort under DE-FG02- 06ER54851 was the subject of a previous Final Report. The theme of this later effort has been unusual confinement effects, or de-confinement effects, in open-field magnetic confinement devices. First, the possibilities in losing axisymmetry were explored. Then a number of issues in rotating plasmamore » were addressed. Most importantly, a spinoff application to plasma separations was recognized, which also resulted in a provisional patent application. (That provisional patent application, however, was not pursued further.) Alpha channeling entails injecting waves into magnetically confined plasma to release energy from one particular ion while ejecting that ion. The ejection of the ion is actually a concomitant effect in releasing energy from the ion to the wave. In rotating plasma, there is the opportunity to store the energy in a radial electric field rather than in waves. In other words, the ejected alpha particle loses its energy to the radial potential, which in turn produces plasma rotation. This is a very useful effect, since producing radial electric fields by other means are technologically more difficult. In fact, one can heat ions, and then eject them, to produce the desired radial field. In each case, there is a separation effect of different ions, which generalizes the original alpha-channeling concept of separating alpha ash from hydrogen. In a further generalization of the separation concept, a double-well filter represents a new way to produce high-throughput separations of ions, potentially useful for nuclear waste remediation.« less

Fabrication of polyimide based microfluidic channels for biosensor devices

NASA Astrophysics Data System (ADS)

Zulfiqar, Azeem; Pfreundt, Andrea; Svendsen, Winnie Edith; Dimaki, Maria

2015-03-01

The ever-increasing complexity of the fabrication process of Point-of-care (POC) devices, due to high demand of functional versatility, compact size and ease-of-use, emphasizes the need of multifunctional materials that can be used to simplify this process. Polymers, currently in use for the fabrication of the often needed microfluidic channels, have limitations in terms of their physicochemical properties. Therefore, the use of a multipurpose biocompatible material with better resistance to the chemical, thermal and electrical environment, along with capability of forming closed channel microfluidics is inevitable. This paper demonstrates a novel technique of fabricating microfluidic devices using polyimide (PI) which fulfills the aforementioned properties criteria. A fabrication process to pattern microfluidic channels, using partially cured PI, has been developed by using a dry etching method. The etching parameters are optimized and compared to those used for fully cured PI. Moreover, the formation of closed microfluidic channel on wafer level by bonding two partially cured PI layers or a partially cured PI to glass with high bond strength has been demonstrated. The reproducibility in uniformity of PI is also compared to the most commonly used SU8 polymer, which is a near UV sensitive epoxy resin. The potential applications of PI processing are POC and biosensor devices integrated with microelectronics.

Pedestrian/bicyclist warning devices and signs at CTA rail-highway grade crossings.

DOT National Transportation Integrated Search

2015-12-14

The focus of this research was on individuals who utilize legally authorized CTA highway-rail crossings with pedestrian access. While trespassing is a major public safety issue, it is not the focus of this research. : An extensive review of the liter...

Polymer Coatings in 3D-Printed Fluidic Device Channels for Improved Cellular Adherence Prior to Electrical Lysis.

PubMed

Gross, Bethany C; Anderson, Kari B; Meisel, Jayda E; McNitt, Megan I; Spence, Dana M

2015-06-16

This paper describes the design and fabrication of a polyjet-based three-dimensional (3D)-printed fluidic device where poly(dimethylsiloxane) (PDMS) or polystyrene (PS) were used to coat the sides of a fluidic channel within the device to promote adhesion of an immobilized cell layer. The device was designed using computer-aided design software and converted into an .STL file prior to printing. The rigid, transparent material used in the printing process provides an optically transparent path to visualize endothelial cell adherence and supports integration of removable electrodes for electrical cell lysis in a specified portion of the channel (1 mm width × 0.8 mm height × 2 mm length). Through manipulation of channel geometry, a low-voltage power source (500 V max) was used to selectively lyse adhered endothelial cells in a tapered region of the channel. Cell viability was maintained on the device over a 5 day period (98% viable), though cell coverage decreased after day 4 with static media delivery. Optimal lysis potentials were obtained for the two fabricated device geometries, and selective cell clearance was achieved with cell lysis efficiencies of 94 and 96%. The bottleneck of unknown surface properties from proprietary resin use in fabricating 3D-printed materials is overcome through techniques to incorporate PDMS and PS.

Correlation Between Euro NCAP Pedestrian Test Results and Injury Severity in Injury Crashes with Pedestrians and Bicyclists in Sweden.

PubMed

Strandroth, Johan; Sternlund, Simon; Lie, Anders; Tingvall, Claes; Rizzi, Matteo; Kullgren, Anders; Ohlin, Maria; Fredriksson, Rikard

2014-11-01

Pedestrians and bicyclists account for a significant share of deaths and serious injuries in the road transport system. The protection of pedestrians in car-to-pedestrian crashes has therefore been addressed by friendlier car fronts and since 1997, the European New Car Assessment Program (Euro NCAP) has assessed the level of protection for most car models available in Europe. In the current study, Euro NCAP pedestrian scoring was compared with real-life injury outcomes in car-to-pedestrian and car-tobicyclist crashes occurring in Sweden. Approximately 1200 injured pedestrians and 2000 injured bicyclists were included in the study. Groups of cars with low, medium and high pedestrian scores were compared with respect to pedestrian injury severity on the Maximum Abbreviated Injury Scale (MAIS)-level and risk of permanent medical impairment (RPMI). Significant injury reductions to both pedestrians and bicyclists were found between low and high performing cars. For pedestrians, the reduction of MAIS2+, MAIS3+, RPMI1+ and RPMI10+ ranged from 20-56% and was significant on all levels except for MAIS3+ injuries. Pedestrian head injuries had the highest reduction, 80-90% depending on level of medical impairment. For bicyclist, an injury reduction was only observed between medium and high performing cars. Significant injury reductions were found for all body regions. It was also found that cars fitted with autonomous emergency braking including pedestrian detection might have a 60-70% lower crash involvement than expected. Based on these results, it was recommended that pedestrian protection are implemented on a global scale to provide protection for vulnerable road users worldwide.

Improving Pedestrian Safety at Signalized Intersections

DOT National Transportation Integrated Search

2012-06-01

Our research investigated methods and technologies to make signalized intersections safer for pedestrians using the capabilities : of accessible pedestrian systems. Our research focused on three technologies: acoustic beaconing, passive pedestrian de...

How do children learn to cross the street? The process of pedestrian safety training

PubMed Central

Schwebel, David C.; Shen, Jiabin; McClure, Leslie A.

2016-01-01

Objective Pedestrian injuries are a leading cause of child death, and may be reduced by training children to cross streets more safely. Such training is most effective when children receive repeated practice at the complex cognitive-perceptual task of judging moving traffic and selecting safe crossing gaps, but there is limited data on how much practice is required for children to reach adult levels of functioning. Using existing data, we examined how children’s pedestrian skill changed over the course of six pedestrian safety training sessions, each comprised of 45 crossings within a virtual pedestrian environment. Methods As part of a randomized controlled trial on pedestrian safety training, 59 children ages 7-8 crossed the street within a semi-immersive virtual pedestrian environment 270 times over a 3-week period (6 sessions of 45 crossings each). Feedback was provided after each crossing, and traffic speed and density was advanced as children’s skill improved. Post-intervention pedestrian behavior was assessed a week later in the virtual environment and compared to adult behavior with identical traffic patterns. Results Over the course of training, children entered traffic gaps more quickly and chose tighter gaps to cross within; their crossing efficiency appeared to increase. By the end of training, some aspects of children’s pedestrian behavior was comparable to adult behavior but other aspects were not, indicating the training was worthwhile but insufficient for most children to achieve adult levels of functioning. Conclusions Repeated practice in a simulated pedestrian environment helps children learn aspects of safe and efficient pedestrian behavior. Six twice-weekly training sessions of 45 crossings each were insufficient for children to reach adult pedestrian functioning, however, and future research should continue to study the trajectory and quantity of child pedestrian safety training needed for children to become competent pedestrians. PMID

How do attitudes, personality traits, and driver behaviors relate to pedestrian behaviors?: A Turkish case.

PubMed

Şimşekoğlu, Özlem

2015-01-01

The present study aimed to investigate the role of pedestrian attitudes and personality traits (social conformity and empathy) on pedestrian behaviors in a Turkish sample. An equally important aim of the study was to examine the association between pedestrian and driver behaviors. The sample included 289 road users including pedestrians and drivers (169 females and 120 males). The participants' age ranged from 15 to 78 years (M = 32.00, SD = 13.89). Data were collected using a self-administered questionnaire. A regression analysis showed that increased age, high level of satisfaction with traffic infrastructure and environment, safer attitudes toward pedestrian violations, and empathy were negatively related to risky pedestrian behaviors, whereas social conformity was positively related. Attitudes were the strongest predictor of pedestrian behaviors. In addition, bivariate correlation analysis showed that all dimensions of pedestrian and driver behaviors were positively correlated with each other, which indicates that a tendency to take risks remains the same regardless of the road user role (i.e., driver vs. pedestrian). Attitudes are strong predictors of pedestrian behaviors. A tendency to take risks as a pedestrian and as a driver is correlated. Results are discussed for their implications to traffic safety campaigns targeting increased pedestrian safety.

Evaluating pedestrian safety improvements : final report.

DOT National Transportation Integrated Search

2012-12-01

The purpose of the study was to evaluate the impact of new pedestrian countermeasure installations on pedestrian safety to assist in informing future pedestrian safety initiatives. In order to address these objectives, the WMU team conducted a litera...

A cell sorting and trapping microfluidic device with an interdigital channel

NASA Astrophysics Data System (ADS)

Tu, Jing; Qiao, Yi; Xu, Minghua; Li, Junji; Liang, Fupeng; Duan, Mengqin; Ju, An; Lu, Zuhong

2016-12-01

The growing interest in cell sorting and trapping is driving the demand for high performance technologies. Using labeling techniques or external forces, cells can be identified by a series of methods. However, all of these methods require complicated systems with expensive devices. Based on inherent differences in cellular morphology, cells can be sorted by specific structures in microfluidic devices. The weir filter is a basic and efficient cell sorting and trapping structure. However, in some existing weir devices, because of cell deformability and high flow velocity in gaps, trapped cells may become stuck or even pass through the gaps. Here, we designed and fabricated a microfluidic device with interdigital channels for cell sorting and trapping. The chip consisted of a sheet of silicone elastomer polydimethylsiloxane and a sheet of glass. A square-wave-like weir was designed in the middle of the channel, comprising the interdigital channels. The square-wave pattern extended the weir length by three times with the channel width remaining constant. Compared with a straight weir, this structure exhibited a notably higher trapping capacity. Interdigital channels provided more space to slow down the rate of the pressure decrease, which prevented the cells from becoming stuck in the gaps. Sorting a mixture K562 and blood cells to trap cells demonstrated the efficiency of the chip with the interdigital channel to sort and trap large and less deformable cells. With stable and efficient cell sorting and trapping abilities, the chip with an interdigital channel may be widely applied in scientific research fields.

Indoor Navigation Design Integrated with Smart Phones and Rfid Devices

NASA Astrophysics Data System (ADS)

Ortakci, Y.; Demiral, E.; Atila, U.; Karas, I. R.

2015-10-01

High rise, complex and huge buildings in the cities are almost like a small city with their tens of floors, hundreds of corridors and rooms and passages. Due to size and complexity of these buildings, people need guidance to find their way to the destination in these buildings. In this study, a mobile application is developed to visualize pedestrian's indoor position as 3D in their smartphone and RFID Technology is used to detect the position of pedestrian. While the pedestrian is walking on his/her way on the route, smartphone will guide the pedestrian by displaying the photos of indoor environment on the route. Along the tour, an RFID (Radio-Frequency Identification) device is integrated to the system. The pedestrian will carry the RFID device during his/her tour in the building. The RFID device will send the position data to the server directly in every two seconds periodically. On the other side, the pedestrian will just select the destination point in the mobile application on smartphone and sent the destination point to the server. The shortest path from the pedestrian position to the destination point is found out by the script on the server. This script also sends the environment photo of the first node on the acquired shortest path to the client as an indoor navigation module.

Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

DOEpatents

Haaland, C.M.; Deeds, W.E.

1999-07-13

A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output. 5 figs.

Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

DOEpatents

Haaland, Carsten M.; Deeds, W. Edward

1999-01-01

A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output.

Is "Safety-in-numbers" theory applies to the pattern of pedestrian accidents in Seoul, South Korea.

NASA Astrophysics Data System (ADS)

Choi, Y.; Yoon, H.

2016-12-01

Every year, about 1.25 million people die of vehicle-related accidents, among which half are pedestrians with higher vulnerability: pedestrian, cyclists and motorcyclist (World Health Organization, 2016). This urges city governments in the world to strive for pedestrian safety and to apply diverse theories to transportation planning and design. The common belief is that the number of pedestrian accidents is directly and positively associated with the volume of pedestrian, however, another hypothesis, called "safety-in-numbers" effect, tells an opposite story in that accident rates declines with increase of the volume of pedestrian. In this study, we examine first, whether the safety-in-numbers theory applies to the pattern of pedestrian accidents in Seoul, and second, further investigate environmental factors that are associated with the pedestrian safety. On the first count, we use geospatial statistical analyses of the multi-year pedestrian accident data collected by Korea Road Traffic Authority (KoRoad) and the pedestrian volume data collected by SK Telecom (SKT). With Kernel Density Estimation and Bivariate Local Moran's I, we identify spatial clustering of pedestrian accidents in the city, and examine whether those locations match with concentrations of pedestrian volume. On the second count, we use statistical analysis, tobit, poisson and negative binomial regression to investigate relationships between pedestrian volume and number of pedestrian accident for the two types of geographic areas by the results of the aforementioned analysis; Area 1- locations of high volume of pedestrian with high number of accident, Area 2- locations of high volume of pedestrian with low number of accident. For environmental factors potentially explaining pedestrian accidents, we include land use composition, number of traffic lanes, crosswalk presence, pedestrian signal, traffic island and sidewalk width in our analysis. This research will be valuable in city governments

Does facing traffic improve pedestrian safety?

PubMed

Luoma, Juha; Peltola, Harri

2013-01-01

This study was designed to evaluate the potential safety importance of the walking direction along a road by examining pedestrian accidents as a function of exposure to risk. The study was limited to rural two-lane roads with no pavement or pedestrian lane. The accident data included police-reported road accidents from Finland between 2006 and 2010 in which a motorized vehicle had struck a pedestrian walking along the road. There were 18 accidents involving a fatally injured pedestrian and 87 accidents involving a non-fatally injured pedestrian. The exposure data collected from the roughly 3400km included 258 pedestrians. The main finding was that the mean effect of facing traffic compared to walking with traffic was a 77% decrease in fatal and in non-fatal injury pedestrian accidents. The results further showed that the effects were greater for main roads than for secondary roads. The main implication of this study is that information about the importance of facing traffic should be reinforced with specific information about its substantial safety benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

Validity of instruments to assess students' travel and pedestrian safety.

PubMed

Mendoza, Jason A; Watson, Kathy; Baranowski, Tom; Nicklas, Theresa A; Uscanga, Doris K; Hanfling, Marcus J

2010-05-18

Safe Routes to School (SRTS) programs are designed to make walking and bicycling to school safe and accessible for children. Despite their growing popularity, few validated measures exist for assessing important outcomes such as type of student transport or pedestrian safety behaviors. This research validated the SRTS school travel survey and a pedestrian safety behavior checklist. Fourth grade students completed a brief written survey on how they got to school that day with set responses. Test-retest reliability was obtained 3-4 hours apart. Convergent validity of the SRTS travel survey was assessed by comparison to parents' report. For the measure of pedestrian safety behavior, 10 research assistants observed 29 students at a school intersection for completion of 8 selected pedestrian safety behaviors. Reliability was determined in two ways: correlations between the research assistants' ratings to that of the Principal Investigator (PI) and intraclass correlations (ICC) across research assistant ratings. The SRTS travel survey had high test-retest reliability (kappa = 0.97, n = 96, p < 0.001) and convergent validity (kappa = 0.87, n = 81, p < 0.001). The pedestrian safety behavior checklist had moderate reliability across research assistants' ratings (ICC = 0.48) and moderate correlation with the PI (r = 0.55, p = < 0.01). When two raters simultaneously used the instrument, the ICC increased to 0.65. Overall percent agreement (91%), sensitivity (85%) and specificity (83%) were acceptable. These validated instruments can be used to assess SRTS programs. The pedestrian safety behavior checklist may benefit from further formative work.

Validity of instruments to assess students' travel and pedestrian safety

PubMed Central

2010-01-01

Background Safe Routes to School (SRTS) programs are designed to make walking and bicycling to school safe and accessible for children. Despite their growing popularity, few validated measures exist for assessing important outcomes such as type of student transport or pedestrian safety behaviors. This research validated the SRTS school travel survey and a pedestrian safety behavior checklist. Methods Fourth grade students completed a brief written survey on how they got to school that day with set responses. Test-retest reliability was obtained 3-4 hours apart. Convergent validity of the SRTS travel survey was assessed by comparison to parents' report. For the measure of pedestrian safety behavior, 10 research assistants observed 29 students at a school intersection for completion of 8 selected pedestrian safety behaviors. Reliability was determined in two ways: correlations between the research assistants' ratings to that of the Principal Investigator (PI) and intraclass correlations (ICC) across research assistant ratings. Results The SRTS travel survey had high test-retest reliability (κ = 0.97, n = 96, p < 0.001) and convergent validity (κ = 0.87, n = 81, p < 0.001). The pedestrian safety behavior checklist had moderate reliability across research assistants' ratings (ICC = 0.48) and moderate correlation with the PI (r = 0.55, p =< 0.01). When two raters simultaneously used the instrument, the ICC increased to 0.65. Overall percent agreement (91%), sensitivity (85%) and specificity (83%) were acceptable. Conclusions These validated instruments can be used to assess SRTS programs. The pedestrian safety behavior checklist may benefit from further formative work. PMID:20482778

Special issue : pedestrian injuries:

DOT National Transportation Integrated Search

1999-03-13

This special issue focuses on effective ways to reduce pedestrian deaths and injuries. Pedestrians represent the second largest group of motor vehicle deaths, second only to passenger vehicle occupant deaths. This study examines some of the most effe...

Traffic safety facts 1994 : pedestrians

DOT National Transportation Integrated Search

1995-01-01

In 1994, 5,472 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1984-1994; and Figure 2, pedestrian fatalities by time of day and day of week, 1994. Of the tables, Tabl...

Traffic safety facts 1995 : pedestrians

DOT National Transportation Integrated Search

1996-01-01

In 1995, 5,585 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1985-1995; and Figure 2, pedestrian fatalities by time of day and day of week, 1995. Of the tables, Tabl...

Traffic safety facts 1996 : pedestrians

DOT National Transportation Integrated Search

1997-01-01

In 1996, 5,412 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1986-1996; and Figure 2, pedestrian fatalities by time of day and day of week, 1996. Of the tables, Tabl...

Traffic safety facts 1993 : pedestrians

DOT National Transportation Integrated Search

1994-01-01

In 1993, 5,638 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1983-1993; and Figure 2, pedestrian fatalities by time of day and day of week, 1993. Of the tables, Tabl...

Pedestrian safety in Virginia : accident characteristics and suggested revisions to Virginia's pedestrian laws.

DOT National Transportation Integrated Search

1981-01-01

The purpose of the research reported here was to evaluate the nature, characteristics, and severity of accidents involving pedestrians in Virginia and to determine whether or not these data would suggest the need for changes in Virginia traffic laws ...

Pedestrian injury mitigation by autonomous braking.

PubMed

Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

2010-11-01

The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness. 2010 Elsevier Ltd. All rights reserved.

Pedestrian safety in Australia

DOT National Transportation Integrated Search

1999-12-01

This report was one in a series of pedestrian safety synthesis reports prepared for the Federal Highway : Administration (FHWA) to document pedestrian safety in other countries. Reports are also available for: : United Kingdom (FHWA-RD-99-089) : Cana...

Pedestrian safety in Sweden

DOT National Transportation Integrated Search

1999-12-01

This report was one in a series of pedestrian safety synthesis reports prepared for the Federal Highway Administration (FHWA) to document pedestrian safety in other countries. Reports are also available for: : United Kingdom (FHWA-RD-99-089) : Canada...

Measuring pedestrian volumes and conflicts. Volume III, Measuring pedestrian volumes : a users manual

DOT National Transportation Integrated Search

1988-03-01

Users of the manual are expected to be in divisions responsible for pedestrian safety in cities, counties, and other jurisdictions. The users manual outlines a step-by-step procedure to measure pedestrian volumes using small count intervals. Appendix...

Testing and evaluation of pedestrian sensors

DOT National Transportation Integrated Search

2007-09-01

The foundation for several pedestrian safety measures is reliable and accurate detection of pedestrians. The main objective of this study was to evaluate sensors for use in a pedestrian safety test bed in College Station, TX. The following sensors we...

Injury severity analysis in taxi-pedestrian crashes: An application of reconstructed crash data using a vehicle black box.

PubMed

Chung, Younshik

2018-02-01

In-vehicle recording devices have enabled recent changes in methodological paradigms for traffic safety research. Such devices include event data recorders (EDRs), vehicle black boxes (VBBs), and various sensors used in naturalistic driving studies (NDSs). These technologies may help improve the validity of models used to assess impacts on traffic safety. The objective of this study is to analyze the injury severity in taxi-pedestrian crashes using the accurate crash data from VBBs, such as the time-to-collision (TTC), speed, angle, and region of the crash. VBB data from a two-year period (2010-2011) were collected from taxis operating in Incheon, South Korea. An ordered probit model was then applied to analyze the injury severity in crashes. Five variables were found to have a greater effect on injury severity: crash speed, crashes in no-median sections, crashes where the secondary impact object of pedestrians was the crash vehicle, crashes where the third impact object of pedestrians was another moving vehicle, and crashes where the third impact region of pedestrians was their head. However, injuries were less severe in crashes where the first impact region on the pedestrian was their leg, crashes with the car moving in a straight line, and crashes involving junior high school students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using Theory to Guide Practice in Children's Pedestrian Safety Education

ERIC Educational Resources Information Center

Cross, Donna; Hall, Margaret; Howat, Peter

2003-01-01

Few pedestrian injury prevention programs appear to articulate the theory upon which their design and evaluation are based. This article describes how theory was used to plan, develop, implement, and evaluate the educational component of a comprehensive child pedestrian intervention. Organizational and planning theories were used to guide the…

Fatalities of pedestrians, bicycle riders, and motorists due to distracted driving motor vehicle crashes in the U.S., 2005-2010.

PubMed

Stimpson, Jim P; Wilson, Fernando A; Muelleman, Robert L

2013-01-01

Distracted driving is an increasingly deadly threat to road safety. This study documents trends in and characteristics of pedestrian, bicycle rider, and other victim deaths caused by distracted drivers on U.S. public roads. We obtained data from the Fatality Analysis Reporting System database from 2005 to 2010 on every crash that resulted in at least one fatality within 30 days occurring on public roads in the U.S. Following the definition used by the National Highway Traffic Safety Administration, we identified distracted driving based on whether police investigators determined that a driver had been using a technological device, including a cell phone, onboard navigation system, computer, fax machine, two-way radio, or head-up display, or had been engaged in inattentive or careless activities. The rate of fatalities per 10 billion vehicle miles traveled increased from 116.1 in 2005 to 168.6 in 2010 for pedestrians and from 18.7 in 2005 to 24.6 in 2010 for bicyclists. Pedestrian victims of distracted driving crashes were disproportionately male, 25-64 years of age, and non-Hispanic white. They were also more likely to die at nighttime, be struck by a distracted driver outside of a marked crosswalk, and be in a metro location. Bicycling victims of distracted crashes were disproportionately male, non-Hispanic white, and struck by a distracted driver outside of a crosswalk. Compared with pedestrians, bicyclists were less likely to be hit in early morning. Distracted drivers are the cause of an increasing share of fatalities found among pedestrians and bicycle riders. Policies are needed to protect pedestrians and bicycle riders as they cross intersections or travel on roadways.

Pedestrian Safer Journey

Science.gov Websites

Pedestrian Safer Journey Skills for Safe Walking for Ages 5 to 18 Use in the classroom or one-on -one. To start, click on an age group below: Ages 5-9 Ages 10-14 Ages 15-18 What is Pedestrian Safer get the conversation started with children and youth. Three videos - one for each of three age groups

Creating fast flow channels in paper fluidic devices to control timing of sequential reactions.

PubMed

Jahanshahi-Anbuhi, Sana; Chavan, Puneet; Sicard, Clémence; Leung, Vincent; Hossain, S M Zakir; Pelton, Robert; Brennan, John D; Filipe, Carlos D M

2012-12-07

This paper reports the development of a method to control the flow rate of fluids within paper-based microfluidic analytical devices. We demonstrate that by simply sandwiching paper channels between two flexible films, it is possible to accelerate the flow of water through paper by over 10-fold. The dynamics of this process are such that the height of the liquid is dependent on time to the power of 1/3. This dependence was validated using three different flexible films (with markedly different contact angles) and three different fluids (water and two silicon oils with different viscosities). These covered channels provide a low-cost method for controlling the flow rate of fluid in paper channels, and can be added following printing of reagents to control fluid flow in selected fluidic channels. Using this method, we redesigned a previously published bidirectional lateral flow pesticide sensor to allow more rapid detection of pesticides while eliminating the need to run the assay in two stages. The sensor is fabricated with sol-gel entrapped reagents (indoxyl acetate in a substrate zone and acetylcholinesterase, AChE, in a sensing zone) present in an uncovered "slow" flow channel, with a second, covered "fast" channel used to transport pesticide samples to the sensing region through a simple paper-flap valve. In this manner, pesticides reach the sensing region first to allow preincubation, followed by delivery of the substrate to generate a colorimetric signal. This format results in a uni-directional device that detects the presence of pesticides two times faster than the original bidirectional sensors.

Simulation of counterflow pedestrian dynamics using spheropolygons

NASA Astrophysics Data System (ADS)

Alonso-Marroquín, Fernando; Busch, Jonathan; Chiew, Coraline; Lozano, Celia; Ramírez-Gómez, Álvaro

2014-12-01

Pedestrian dynamic models are typically designed for comfortable walking or slightly congested conditions and typically use a single disk or combination of three disks for the shape of a pedestrian. Under crowd conditions, a more accurate pedestrian shape has advantages over the traditional single or three-disks model. We developed a method for simulating pedestrian dynamics in a large dense crowd of spheropolygons adapted to the cross section of the chest and arms of a pedestrian. Our numerical model calculates pedestrian motion from Newton's second law, taking into account viscoelastic contact forces, contact friction, and ground-reaction forces. Ground-reaction torque was taken to arise solely from the pedestrians' orientation toward their preferred destination. Simulations of counterflow pedestrians dynamics in corridors were used to gain insight into a tragic incident at the Madrid Arena pavilion in Spain, where five girls were crushed to death. The incident took place at a Halloween Celebration in 2012, in a long, densely crowded hallway used as entrance and exit at the same time. Our simulations reconstruct the mechanism of clogging in the hallway. The hypothetical case of a total evacuation order was also investigated. The results highlights the importance of the pedestrians' density and the effect of counterflow in the onset of avalanches and clogging and provides an estimation of the number of injuries based on a calculation of the contact-force network between the pedestrians.

Simulation of counterflow pedestrian dynamics using spheropolygons.

PubMed

Alonso-Marroquín, Fernando; Busch, Jonathan; Chiew, Coraline; Lozano, Celia; Ramírez-Gómez, Álvaro

2014-12-01

Pedestrian dynamic models are typically designed for comfortable walking or slightly congested conditions and typically use a single disk or combination of three disks for the shape of a pedestrian. Under crowd conditions, a more accurate pedestrian shape has advantages over the traditional single or three-disks model. We developed a method for simulating pedestrian dynamics in a large dense crowd of spheropolygons adapted to the cross section of the chest and arms of a pedestrian. Our numerical model calculates pedestrian motion from Newton's second law, taking into account viscoelastic contact forces, contact friction, and ground-reaction forces. Ground-reaction torque was taken to arise solely from the pedestrians' orientation toward their preferred destination. Simulations of counterflow pedestrians dynamics in corridors were used to gain insight into a tragic incident at the Madrid Arena pavilion in Spain, where five girls were crushed to death. The incident took place at a Halloween Celebration in 2012, in a long, densely crowded hallway used as entrance and exit at the same time. Our simulations reconstruct the mechanism of clogging in the hallway. The hypothetical case of a total evacuation order was also investigated. The results highlights the importance of the pedestrians' density and the effect of counterflow in the onset of avalanches and clogging and provides an estimation of the number of injuries based on a calculation of the contact-force network between the pedestrians.

A comparison of safety benefits of pedestrian countdown signals with and without pushbuttons in Michigan.

PubMed

Boateng, Richard Atta; Kwigizile, Valerian; Oh, Jun-Seok

2018-04-11

This study evaluated the safety impacts of PCSs with and without pushbuttons based on pedestrian crashes and pedestrian injuries in Michigan. This study used ten years of intersection data: five years before PCSs were installed and five years after they were installed, along with a comparison group, to evaluate the crash impacts of PCSs: at 107 intersections the PCS had a pushbutton and at 96 it did not. At these intersections, and at their comparison sites (where no PCS was installed), crash data (from 2004-2016) were examined, along with traffic and geometric characteristics, population, education and poverty levels data. Intersections where PCSs with pushbuttons have been installed showed a 29 percent reduction in total pedestrian crashes and a 30 percent reduction in fatal/injury pedestrian crashes. Further, when considering only pedestrians age 65 and below, these respective reductions are 33 and 35 percent. Intersections with PCSs but without pushbuttons did not show any significant change in any type of pedestrian crash. Although the Manual of Uniform Traffic Control Devices (FHWA, 2009) requires the use of PCSs at new traffic signal installations, this study suggests a safety benefit of installing PCSs with pushbutton at signals where a PCS without a pushbutton is present.

Kinetic theory of situated agents applied to pedestrian flow in a corridor

NASA Astrophysics Data System (ADS)

Rangel-Huerta, A.; Muñoz-Meléndez, A.

2010-03-01

A situated agent-based model for simulation of pedestrian flow in a corridor is presented. In this model, pedestrians choose their paths freely and make decisions based on local criteria for solving collision conflicts. The crowd consists of multiple walking agents equipped with a function of perception as well as a competitive rule-based strategy that enables pedestrians to reach free access areas. Pedestrians in our model are autonomous entities capable of perceiving and making decisions. They apply socially accepted conventions, such as avoidance rules, as well as individual preferences such as the use of specific exit points, or the execution of eventual comfort turns resulting in spontaneous changes of walking speed. Periodic boundary conditions were considered in order to determine the density-average walking speed, and the density-average activity with respect to specific parameters: comfort angle turn and frequency of angle turn of walking agents. The main contribution of this work is an agent-based model where each pedestrian is represented as an autonomous agent. At the same time the pedestrian crowd dynamics is framed by the kinetic theory of biological systems.

Car-to-pedestrian collision reconstruction with injury as an evaluation index.

PubMed

Weng, Yiliu; Jin, Xianlong; Zhao, Zhijie; Zhang, Xiaoyun

2010-07-01

Reconstruction of accidents is currently considered as a useful means in the analysis of accidents. By multi-body dynamics and numerical methods, and by adopting vehicle and pedestrian models, the scenario of the crash can often be simulated. When reconstructing the collisions, questions often arise regarding the criteria for the evaluation of simulation results. This paper proposes a reconstruction method for car-to-pedestrian collisions based on injuries of the pedestrians. In this method, pedestrian injury becomes a critical index in judging the correctness of the reconstruction result and guiding the simulation process. Application of this method to a real accident case is also presented in this paper. The study showed a good agreement between injuries obtained by numerical simulation and that by forensic identification. Copyright 2010 Elsevier Ltd. All rights reserved.

Expanding pedestrian injury risk to the body region level: how to model passive safety systems in pedestrian injury risk functions.

PubMed

Niebuhr, Tobias; Junge, Mirko; Achmus, Stefanie

2015-01-01

Assessment of the effectiveness of advanced driver assistance systems (ADAS) plays a crucial role in accident research. A common way to evaluate the effectiveness of new systems is to determine the potentials for injury severity reduction. Because injury risk functions describe the probability of an injury of a given severity conditional on a technical accident severity (closing speed, delta V, barrier equivalent speed, etc.), they are predestined for such evaluations. Recent work has stated an approach on how to model the pedestrian injury risk in pedestrian-to-passenger car accidents as a family of functions. This approach gave explicit and easily interpretable formulae for the injury risk conditional on the closing speed of the car. These results are extended to injury risk functions for pedestrian body regions. Starting with a double-checked German In-depth Accident Study (GIDAS) pedestrian-to-car accident data set (N = 444) and a functional-anatomical definition of the body regions, investigations on the influence of specific body regions on the overall injury severity will be presented. As the measure of injury severity, the ISSx, a rescaled version of the well-known Injury Severity Score (ISS), was used. Though traditional ISS is computed by summation of the squares of the 3 most severe injured body regions, ISSx is computed by the summation of the exponentials of the Abbreviated Injury Scale (AIS) severities of the 3 most severely injured body regions. The exponentials used are scaled to fit the ISS range of values between 0 and 75. Three body regions (head/face/neck, thorax, hip/legs) clearly dominated abdominal and upper extremity injuries; that is, the latter 2 body regions had no influence at all on the overall injury risk over the range of technical accident severities. Thus, the ISSx is well described by use of the injury codes from the same body regions for any pedestrian injury severity. As a mathematical consequence, the ISSx becomes explicitly

Investigating Improvements to Pedestrian Crossings with an Emphasis on the Rectangular Rapid-Flashing Beacon

DOT National Transportation Integrated Search

2015-06-01

The goal of this research effort was to improve pedestrian safety at urban and suburban crossing locations by identifying and evaluating low- to medium-cost pedestrian treatments. The treatments were to have the potential to reduce pedestrian crashes...

Portable two-channel PPG cardiovascular sensor device

NASA Astrophysics Data System (ADS)

Spigulis, Janis; Erts, Renars; Ozols, Maris

2003-10-01

A portable sensor device for simultaneous detection and processing of skin-remitted optical signals from any two sites of the body has been developed and tested. The photoplethysmography (PPG) principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. The newly developed two-channel approach allows to estimate the vascular blood flow resistance by analysis of time shifts between the PPG pulses detected at different body sites. Potential of the sensor device for express-assessment of human cardio-vascular condition and for body fitness tests has been demonstrated.

Detecting New Pedestrian Facilities from VGI Data Sources

NASA Astrophysics Data System (ADS)

Zhong, S.; Xie, Z.

2017-12-01

Pedestrian facility (e.g. footbridge, pedestrian crossing and underground passage) information is an important basic data of location based service (LBS) for pedestrians. However, timely updating pedestrian facility information challenges due to facilities change frequently. Previous pedestrian facility information collecting and updating tasks are mainly completed by highly trained specialized persons. However, this conventional approach has several disadvantages such as high cost, long update cycle and so on. Volunteered Geographic Information (VGI) has proven efficiency to provide new, free and fast growing spatial data. Pedestrian trajectory, which can be seen as measurements of real pedestrian road, is one of the most valuable information of VGI data. Although the accuracy of the trajectories is not too high, due to the large number of measurements, an improvement of quality of the road information can be achieved. Thus, we develop a method for detecting new pedestrian facilities based on the current road network and pedestrian trajectories. Specifically, 1) by analyzing speed, distance and direction, those outliers of pedestrian trajectories are removed, 2) a road network matching algorithm is developed for eliminating redundant trajectories, and 3) a space-time cluster algorithm is adopted for detecting new walking facilities. The performance of the method is evaluated with a series of experiments conducted on a part of the road network of Heifei and a large number of real pedestrian trajectories, and verified the results by using Tencent Street map. The results show that the proposed method is able to detecting new pedestrian facilities from VGI data accurately. We believe that the proposed method provides an alternative way for general road data acquisition, and can improve the quality of LBS for pedestrians.

2000 Metropolitan Bicycle and Pedestrian Plan

DOT National Transportation Integrated Search

2000-12-01

The Metropolitan Bicycle and Pedestrian Plan establishes a 20-year vision for bicycle and pedestrian facilities in the Fargo-Moorhead metropolitan area and its environs. It is the intent of the Metropolitan Bicycle and Pedestrian Committee, which gui...

Pedestrian/bicyclist warning devices and signs at highway-rail and pathway-rail grade crossings.

DOT National Transportation Integrated Search

2013-04-01

Federal reporting shows a relatively constant number of pedestrian and bicycle fatalities at highway-rail and : pathway-rail grade crossings over the past 10 years. This is in contrast to a marked decrease in trainvehicle : collisions at highway-r...

Pedestrian recognition using automotive radar sensors

NASA Astrophysics Data System (ADS)

Bartsch, A.; Fitzek, F.; Rasshofer, R. H.

2012-09-01

The application of modern series production automotive radar sensors to pedestrian recognition is an important topic in research on future driver assistance systems. The aim of this paper is to understand the potential and limits of such sensors in pedestrian recognition. This knowledge could be used to develop next generation radar sensors with improved pedestrian recognition capabilities. A new raw radar data signal processing algorithm is proposed that allows deep insights into the object classification process. The impact of raw radar data properties can be directly observed in every layer of the classification system by avoiding machine learning and tracking. This gives information on the limiting factors of raw radar data in terms of classification decision making. To accomplish the very challenging distinction between pedestrians and static objects, five significant and stable object features from the spatial distribution and Doppler information are found. Experimental results with data from a 77 GHz automotive radar sensor show that over 95% of pedestrians can be classified correctly under optimal conditions, which is compareable to modern machine learning systems. The impact of the pedestrian's direction of movement, occlusion, antenna beam elevation angle, linear vehicle movement, and other factors are investigated and discussed. The results show that under real life conditions, radar only based pedestrian recognition is limited due to insufficient Doppler frequency and spatial resolution as well as antenna side lobe effects.

The flashing right turn signal with pedestrian indication : human factors studies to understand the potential of a new signal to increase awareness of and attention to crossing pedestrians, [summary].

DOT National Transportation Integrated Search

2015-12-01

The Florida Department of Transportation (FDOT) has placed a high priority on understanding : the nature of pedestrian injury and fatality incidents and on developing interventions that will : make Floridas roads safer for pedestrians.

Carrying Position Independent User Heading Estimation for Indoor Pedestrian Navigation with Smartphones

PubMed Central

Deng, Zhi-An; Wang, Guofeng; Hu, Ying; Cui, Yang

2016-01-01

This paper proposes a novel heading estimation approach for indoor pedestrian navigation using the built-in inertial sensors on a smartphone. Unlike previous approaches constraining the carrying position of a smartphone on the user’s body, our approach gives the user a larger freedom by implementing automatic recognition of the device carrying position and subsequent selection of an optimal strategy for heading estimation. We firstly predetermine the motion state by a decision tree using an accelerometer and a barometer. Then, to enable accurate and computational lightweight carrying position recognition, we combine a position classifier with a novel position transition detection algorithm, which may also be used to avoid the confusion between position transition and user turn during pedestrian walking. For a device placed in the trouser pockets or held in a swinging hand, the heading estimation is achieved by deploying a principal component analysis (PCA)-based approach. For a device held in the hand or against the ear during a phone call, user heading is directly estimated by adding the yaw angle of the device to the related heading offset. Experimental results show that our approach can automatically detect carrying positions with high accuracy, and outperforms previous heading estimation approaches in terms of accuracy and applicability. PMID:27187391

Evaluation of pedestrian safety at intersections: A theoretical framework based on pedestrian-vehicle interaction patterns.

PubMed

Ni, Ying; Wang, Menglong; Sun, Jian; Li, Keping

2016-11-01

Pedestrians are the most vulnerable road users, and pedestrian safety has become a major research focus in recent years. Regarding the quality and quantity issues with collision data, conflict analysis using surrogate safety measures has become a useful method to study pedestrian safety. However, given the inequality between pedestrians and vehicles in encounters and the multiple interactions between pedestrians and vehicles, it is insufficient to simply use the same indicator(s) or the same way to aggregate indicators for all conditions. In addition, behavioral factors cannot be neglected. To better use information extracted from trajectories for safety evaluation and pay more attention on effects of behavioral factors, this paper develops a more sophisticated framework for pedestrian conflict analysis that takes pedestrian-vehicle interactions into consideration. A concept of three interaction patterns has been proposed for the first time, namely "hard interaction," "no interaction," and "soft-interaction." Interactions have been categorized under one of these patterns by analyzing profiles of speed and conflict indicators during the whole interactive processes. In this paper, a support vector machine (SVM) approach has been adopted to classify severity levels for a dataset including 1144 events extracted from three intersections in Shanghai, China, followed by an analysis of variable importance. The results revealed that different conflict indicators have different contributions to indicating the severity level under various interaction patterns. Therefore, it is recommended either to use specific conflict indicators or to use weighted indicator aggregation for each interaction pattern when evaluating pedestrian safety. The implementation has been carried out at the fourth crosswalk, and the results indicate that the proposed method can achieve a higher accuracy and better robustness than conventional methods. Furthermore, the method is helpful for better

Towards an integrated approach of pedestrian behaviour and exposure.

PubMed

Papadimitriou, Eleonora

2016-07-01

In this paper, an integrated methodology for the analysis of pedestrian behaviour and exposure is proposed, allowing to identify and quantify the effect of pedestrian behaviour, road and traffic characteristics on pedestrian risk exposure, for each pedestrian and for populations of pedestrians. The paper builds on existing research on pedestrian exposure, namely the Routledge microscopic indicator, proposes adjustments to take into account road, traffic and human factors and extends the use of this indicator on area-wide level. Moreover, this paper uses integrated choice and latent variables (ICLV) models of pedestrian behaviour, taking into account road, traffic and human factors. Finally, a methodology is proposed for the integrated estimation of pedestrian behaviour and exposure on the basis of road, traffic and human factors. The method is tested with data from a field survey in Athens, Greece, which used pedestrian behaviour observations as well as a questionnaire on human factors of pedestrian behaviour. The data were used (i) to develop ICLV models of pedestrian behaviour and (ii) to estimate the behaviour and exposure of pedestrians for different road, traffic and behavioural scenarios. The results suggest that both pedestrian behaviour and exposure are largely defined by a small number of factors: road type, traffic volume and pedestrian risk-taking. The probability for risk-taking behaviour and the related exposure decrease in less demanding road and traffic environments. A synthesis of the results allows to enhance the understanding of the interactions between behaviour and exposure of pedestrians and to identify conditions of increased risk exposure. These conditions include principal urban arterials (where risk-taking behaviour is low but the related exposure is very high) and minor arterials (where risk-taking behaviour is more frequent, and the related exposure is still high). A "paradox" of increased risk-taking behaviour of pedestrians with low

Longitudinal channelizing devices along business entrances in work zones : [summary].

DOT National Transportation Integrated Search

2015-04-01

The Florida Department of Transportations Design Standards requires placement of business : entrance signs and channelizing devices at business entrances in work zones. The Design : Standards also specifies the layout of the signs and devices. Typ...

Psychological distance of pedestrian at the bus terminal area

NASA Astrophysics Data System (ADS)

Firdaus Mohamad Ali, Mohd; Salleh Abustan, Muhamad; Hidayah Abu Talib, Siti; Abustan, Ismail; Rahman, Noorhazlinda Abd; Gotoh, Hitoshi

2018-03-01

Walking is a part of transportation modes that is effective for pedestrian in either short or long trips. All people are classified as pedestrian because people do walk every day and the higher number of people walking will lead to crowd conditions and that is the reason of the importance to study about the behaviour of pedestrian specifically the psychological distance in both indoor and outdoor. Nowadays, the number of studies of crowd dynamics among pedestrian have increased due to the concern about the safety issues primarily related to the emergency cases such as fire, earthquake, festival and etc. An observation of pedestrian was conducted at one of the main bus terminals in Kuala Lumpur with the main objective to obtain pedestrian psychological distance and it took place for 45 minutes by using a camcorder that was set up by using a tripod on the upper floor from the area of observation at the main lobby and the trapped area was approximately 100 m2. The analysis was focused on obtaining the gap between pedestrian based on two different categories, which are; (a) Pedestrian with relationship, and (b) Pedestrian without relationship. In total, 1,766 data were obtained during the analysis in which 561 data were obtained for `Pedestrian with relationship' and 1,205 data were obtained for "Pedestrian without relationship". Based on the obtained results, "Pedestrian without relationship" had shown a slightly higher average value of psychological distance between them compare to "Pedestrian with relationship" with the results of 1.6360m and 1.5909m respectively. In gender case, "Pedestrian without relationship" had higher mean of psychological distance in all three categories as well. Therefore, it can be concluded that pedestrian without relationship tend to have longer distance when walking in crowds.

Managing Pedestrian and Car Interactions

DOT National Transportation Integrated Search

2017-05-26

In urban areas and especially in inner cities, pedestrians crossing the road considerably influence the road traffic flow. For political (environmental) reasons, priority could be given to pedestrians. A larger number of crossings reduces the pedestr...

Pedestrian Friendly Traffic Signal Control.

DOT National Transportation Integrated Search

2016-01-01

This project continues research aimed at real-time detection and use of pedestrian : traffic flow information to enhance adaptive traffic signal control in urban areas : where pedestrian traffic is substantial and must be given appropriate attention ...

Pedestrians' adherence to road traffic regulations on the N1 Highway in Accra, Ghana.

PubMed

Noora, Charles Lwanga; Afari, Edwin Andrews; Nuoh, Robert Domo; Adjei, Eric Yirenkyi; Anthony, Gershon Kobla; Abdulai, Marijanatu; Sackey, Samuel Oko; Kenu, Ernest; Nyarko, Kofi Mensah

2016-01-01

Pedestrian behavior and adherence to road traffic regulation is vital in the prevention and control of road traffic accidents (RTA) especially on highways in Ghana. We assessed pedestrians' adherence to road crossing regulations on the George Walker Bush (N1) Highway in Accra. We conducted a cross sectional study of pedestrians crossing the N1 highway from both sides of the road between 7:00 am and 11:00am. We observed all pedestrians using a checklist and interviewed 413 using a structured questionnaire. We collected data on basic demographics, and pedestrians' knowledge on road crossing (exposures). Data was, cleaned and analyzed using Epi-info version 3.5.4. Pearson Chi-square was used to assess differences in proportions for categorical variables. Binary logistic regression was used to test for association between pedestrian choice of route and exposures. We observed (n = 1856) pedestrians crossing the road during the study period; 1155 (62.2%) males, 461 (24.8%) did not use the approved route(s). Majority 317(76.8%) were adults between the ages of 20-49, mostly males 265 (56.4%). Most people (92.7%) had at least basic education. AOR for sex (male) was 1.7(1.1-2.6), and regular use of Highway (always) was 0.4(0.2-0.8) at 95% CI. One out of every 4pedestrians using the N1 Highway used an unapproved route. Majority of pedestrians who regularly cross the Highway at unapproved routes were males. We recommend vigorous public education and addition of more footbridges.

Use of traffic channelization devices at highway-rail grade crossings

DOT National Transportation Integrated Search

2012-08-31

Traffic channelization devices have found new application at highway-rail grade crossings with active warning devices. Numerous studies conducted at locations where they have been installed show positive changes in unsafe driver behavior as a result ...

Risks of pedestrian serious injuries and fatalities associated with impact velocities of cars in car-versus-pedestrian accidents in Japan.

PubMed

Matsui, Yasuhiro; Oikawa, Shoko; Ando, Kenichi

2013-11-01

The first purpose of this study is to clarify the relation between the car impact velocity and pedestrian injury severity or mortality risk. We investigated the frequency of serious injuries and fatalities of pedestrians using vehicle-pedestrian accident data from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The vehicle types considered are sedans, minivans, and box vans (ordinary automobiles) and light passenger cars and light cargo vans (light automobiles). The results revealed that a 10-km/h reduction in impact velocity could mitigate severe pedestrian injuries in cases involving impact velocities of 40 km/h or more for the five vehicle types analyzed. Specifically, if the impact velocity was 30 km/h or less, the frequency of serious injuries was less than 27% and the frequency of fatalities was less than 5% for the five vehicle types. Therefore, if the collision damage mitigation braking system (CDMBS) that uses a sensor to detect pedestrians can effectively reduce the impact velocity for various vehicle types, pedestrian injuries will be greatly mitigated. The second purpose of this study is to identify the factors that affect injury risk. Impact experiments were conducted in which a sedan impacted against a pedestrian full-scale dummy at 40 km/h and a pedestrian headform impactor was impacted against a road surface. The results indicated that the risk of pedestrian serious injury was significantly affected by multiple impact conditions, such as the pedestrian height, car impact velocity, car frontal shape, and car stiffness in cases where the car impacted the pedestrian's head, the degrees of influence of which were driven by the vehicle impact velocity.

PHOTOVOICE: Reducing pedestrian injuries in children.

PubMed

Van Oss, Tracy; Quinn, Danielle; Viscosi, Pauline; Bretscher, Kristen

2013-01-01

Pedestrian injury is the second leading cause of injury related death for children. The purpose of this research project was to determine the effectiveness of pedestrian and road traffic safety education with children, as part of the Walk This Way program through Safe Kids USA. Through the implementation of PHOTOVOICE, a project that captured children's narratives coinciding with a photograph, children engaged in community exploration to identify pedestrian hazards in their communities and explore possible solutions utilizing their photography and narrations. Children participated in an engaging educational session, a community fieldtrip, and reflection. Results concluded that, despite a small increase in post test scores, an increase in awareness of hazards in the community and successful identification of community hazards was achieved. The goal of this research project was determine the effectiveness of a hands-on pedestrian and road traffic safety educational program with children. The results of this research project will be integrated with similar projects completed across the country through the program Walk This Way with Safe Kids USA. Both this research project and the Walk This Way program aim to promote behavior change in children and create safer communities to reduce pedestrian related injury. The overall goal of this research project andthe Walk This Way program is to increase education on a national level in regards to pedestrian safety for children and provide a basis for lobbying for public policy changes pertaining to road and pedestrian safety.

Access to pedestrian roads, daily activities, and physical performance of adolescents.

PubMed

Sjolie, A N

2000-08-01

A cross-sectional study using a questionnaire and physical tests was performed. To study how access to pedestrian roads and daily activities are related to low back strength, low back mobility, and hip mobility in adolescents. Although many authorities express concern about the passive lifestyle of adolescents, little is known about associations between daily activities and physical performance. This study compared 38 youths in a community lacking access to pedestrian roads with 50 youths in nearby area providing excellent access to pedestrian roads. A standardized questionnaire was used to obtain data about pedestrian roads, school journeys, and activities from the local authorities and the pupils. Low back strength was tested as static endurance strength, low back mobility by modified Schober techniques, and hip mobility by goniometer. For statistical analyses, a P value of 0.05 or less determined significance. In the area using school buses, the pupils had less low back extension, less hamstring flexibility, and less hip abduction, flexion, and extension than pupils in the area with pedestrian roads. Multivariate analyses showed no associations between walking or bicycling to school and anatomic function, but regular walking or bicycling to leisure-time activities associated positively with low back strength, low back extension, hip flexion, and extension. Distance by school bus associated negatively with hip abduction, hip flexion, hip extension, and hamstring flexibility (P<0.001). Time spent on television or computer associated negatively but insignificantly with low back strength, hamstring flexibility, hip abduction, and flexion (P<0.1). The results indicate that access to pedestrian roads and other lifestyle factors are associated with physical performance.

Oregon bicycle and pedestrian plan

DOT National Transportation Integrated Search

1998-01-01

This bicycle and pedestrian plan for Oregon covers the following subjects and chapter headings: I-1. the importance of bicycling and walking; 2. state and federal laws relating to bicycle and pedestrian facilities; 3. current conditions for pedestria...

Aggregated channels network for real-time pedestrian detection

NASA Astrophysics Data System (ADS)

Ghorban, Farzin; Marín, Javier; Su, Yu; Colombo, Alessandro; Kummert, Anton

2018-04-01

Convolutional neural networks (CNNs) have demonstrated their superiority in numerous computer vision tasks, yet their computational cost results prohibitive for many real-time applications such as pedestrian detection which is usually performed on low-consumption hardware. In order to alleviate this drawback, most strategies focus on using a two-stage cascade approach. Essentially, in the first stage a fast method generates a significant but reduced amount of high quality proposals that later, in the second stage, are evaluated by the CNN. In this work, we propose a novel detection pipeline that further benefits from the two-stage cascade strategy. More concretely, the enriched and subsequently compressed features used in the first stage are reused as the CNN input. As a consequence, a simpler network architecture, adapted for such small input sizes, allows to achieve real-time performance and obtain results close to the state-of-the-art while running significantly faster without the use of GPU. In particular, considering that the proposed pipeline runs in frame rate, the achieved performance is highly competitive. We furthermore demonstrate that the proposed pipeline on itself can serve as an effective proposal generator.

Impact of grade separator on pedestrian risk taking behavior.

PubMed

Khatoon, Mariya; Tiwari, Geetam; Chatterjee, Niladri

2013-01-01

Pedestrians on Delhi roads are often exposed to high risks. This is because the basic needs of pedestrians are not recognized as a part of the urban transport infrastructure improvement projects in Delhi. Rather, an ever increasing number of cars and motorized two-wheelers encourage the construction of large numbers of flyovers/grade separators to facilitate signal free movement for motorized vehicles, exposing pedestrians to greater risk. This paper describes the statistical analysis of pedestrian risk taking behavior while crossing the road, before and after the construction of a grade separator at an intersection of Delhi. A significant number of pedestrians are willing to take risks in both before and after situations. The results indicate that absence of signals make pedestrians behave independently, leading to increased variability in their risk taking behavior. Variability in the speeds of all categories of vehicles has increased after the construction of grade separators. After the construction of the grade separator, the waiting time of pedestrians at the starting point of crossing has increased and the correlation between waiting times and gaps accepted by pedestrians show that after certain time of waiting, pedestrians become impatient and accepts smaller gap size to cross the road. A Logistic regression model is fitted by assuming that the probability of road crossing by pedestrians depends on the gap size (in s) between pedestrian and conflicting vehicles, sex, age, type of pedestrians (single or in a group) and type of conflicting vehicles. The results of Logistic regression explained that before the construction of the grade separator the probability of road crossing by the pedestrian depends on only the gap size parameter; however after the construction of the grade separator, other parameters become significant in determining pedestrian risk taking behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pedestrian injuries due to collisions with bicycles in New York and California.

PubMed

Tuckel, Peter; Milczarski, William; Maisel, Richard

2014-12-01

Scant attention has been given to pedestrians injured in accidents resulting from collisions with cyclists. This scholarly neglect is surprising given the growing popularity of cycling. This study examines the incidence of pedestrians injured by cyclists in New York between 2004 to 2011 and in California from 2005 to 2011. The study also profiles the pedestrians injured in these two states during these two time frames. The data for this study are based upon patient-level hospital records from New York and California. The data for New York comes from the Statewide Planning and Research Cooperative System (SPARCS) under the auspices of New York State's Department of Health. The data for California come from two sources: the Healthcare Cost and Utilization Project (HCUP) and the California Office of Statewide Health Planning and Development. The rate of pedestrians injured in collisions with cyclists has decreased over time. This decline has occurred despite the increase in the number of cyclists in these states during this same time period. Two possible explanations for this decline are: (a) less exposure of children to cyclists, and (b) improvements in the cycling infrastructure. Although the rate of injuries to pedestrians from collisions with cyclists has been decreasing, improvements to the cycling infrastructure will need to continue. Bike lanes, particularly protected bike lanes, have been shown to be an effective way of reducing cycling-pedestrian accidents. The results of the current study are consistent with this research. Educational campaigns aimed at cyclists that emphasize the safety of all road users--including pedestrians--will also need to continue to assure that this downward trend in the number of accidents is not reversed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multiple pedestrian detection using IR LED stereo camera

NASA Astrophysics Data System (ADS)

Ling, Bo; Zeifman, Michael I.; Gibson, David R. P.

2007-09-01

As part of the U.S. Department of Transportations Intelligent Vehicle Initiative (IVI) program, the Federal Highway Administration (FHWA) is conducting R&D in vehicle safety and driver information systems. There is an increasing number of applications where pedestrian monitoring is of high importance. Visionbased pedestrian detection in outdoor scenes is still an open challenge. People dress in very different colors that sometimes blend with the background, wear hats or carry bags, and stand, walk and change directions unpredictably. The background is various, containing buildings, moving or parked cars, bicycles, street signs, signals, etc. Furthermore, existing pedestrian detection systems perform only during daytime, making it impossible to detect pedestrians at night. Under FHWA funding, we are developing a multi-pedestrian detection system using IR LED stereo camera. This system, without using any templates, detects the pedestrians through statistical pattern recognition utilizing 3D features extracted from the disparity map. A new IR LED stereo camera is being developed, which can help detect pedestrians during daytime and night time. Using the image differencing and denoising, we have also developed new methods to estimate the disparity map of pedestrians in near real time. Our system will have a hardware interface with the traffic controller through wireless communication. Once pedestrians are detected, traffic signals at the street intersections will change phases to alert the drivers of approaching vehicles. The initial test results using images collected at a street intersection show that our system can detect pedestrians in near real time.

Research of Pedestrian Crossing Safety Facilities Based on the Video Detection

NASA Astrophysics Data System (ADS)

Li, Sheng-Zhen; Xie, Quan-Long; Zang, Xiao-Dong; Tang, Guo-Jun

Since that the pedestrian crossing facilities at present is not perfect, pedestrian crossing is in chaos and pedestrians from opposite direction conflict and congest with each other, which severely affects the pedestrian traffic efficiency, obstructs the vehicle and bringing about some potential security problems. To solve these problems, based on video identification, a pedestrian crossing guidance system was researched and designed. It uses the camera to monitor the pedestrians in real time and sums up the number of pedestrians through video detection program, and a group of pedestrian's induction lamp array is installed at the interval of crosswalk, which adjusts color display according to the proportion of pedestrians from both sides to guide pedestrians from both opposite directions processing separately. The emulation analysis result from cellular automaton shows that the system reduces the pedestrian crossing conflict, shortens the time of pedestrian crossing and improves the safety of pedestrians crossing.

Have pedestrian subsystem tests improved passenger car front shape?

PubMed

Li, Guibing; Wang, Fang; Otte, Dietmar; Cai, Zhihua; Simms, Ciaran

2018-06-01

Subsystem impactor tests are the main approaches for evaluation of safety performance of vehicle front design for pedestrian protection in legislative regulations. However, the main aspects of vehicle safety for pedestrians are shape and stiffness, and though it is clear that subsystem impact tests encourage lower vehicle front stiffness, it is unclear whether they promote improved vehicle front shapes for pedestrian protection. The purpose of this paper is therefore to investigate the effects of European pedestrian safety regulations on passenger car front shape and pedestrian injury risk using recent German In-Depth Accident Study (GIDAS) pedestrian collision data and numerical simulations. Firstly, a sample of 579 pedestrian collision cases involving 190 different car models between 2000-2015 extracted from the GIDAS was used to compare front-end shapes of passenger cars manufactured before and after the legislative pedestrian safety regulations were introduced in Europe. The focus was on changes in passenger car front shape and differences in pedestrian AIS2+ (Abbreviated Injury Scale at least level 2) leg, pelvis/femur and head injury risk observed in collisions. Multi-body simulations were also used to assess changes in vehicle aggressivity due to the observed changes in vehicle shape. The results show that newer passenger cars tend to have a flatter and wider bumper, higher bonnet leading edge, shorter and steeper bonnet and a shallower windscreen. Both the collision data and the numerical simulations indicate that newer passenger car front bumper designs are significantly safer for pedestrians' legs. However, the results also show that the higher bonnet leading edge in newer passenger cars is poor for pedestrian pelvis/femur protection, even though newer cars show an obviously lower AIS2+ injury risk to younger pedestrians in collisions. Newer cars have a lower AIS2+ head injury risk for pedestrians in collisions, but the numerical analysis indicate that

Analyzing pedestrian crash injury severity under different weather conditions.

PubMed

Li, Duo; Ranjitkar, Prakash; Zhao, Yifei; Yi, Hui; Rashidi, Soroush

2017-05-19

Pedestrians are the most vulnerable road users due to the lack of mass, speed, and protection compared to other types of road users. Adverse weather conditions may reduce road friction and visibility and thus increase crash risk. There is limited evidence and considerable discrepancy with regard to impacts of weather conditions on injury severity in the literature. This article investigated factors affecting pedestrian injury severity level under different weather conditions based on a publicly available accident database in Great Britain. Accident data from Great Britain that are publicly available through the STATS19 database were analyzed. Factors associated with pedestrian, driver, and environment were investigated using a novel approach that combines a classification and regression tree with random forest approach. Significant severity predictors under fine weather conditions from the models included speed limits, pedestrian age, light conditions, and vehicle maneuver. Under adverse weather conditions, the significant predictors were pedestrian age, vehicle maneuver, and speed limit. Elderly pedestrians are associated with higher pedestrian injury severities. Higher speed limits increase pedestrian injury severity. Based on the research findings, recommendations are provided to improve pedestrian safety.

Visually Impaired Pedestrian Safety at Roundabout Crossings

DOT National Transportation Integrated Search

2017-11-01

Pedestrians are some of the most vulnerable road users. This becomes more apparent : at intersections, where pedestrians are unprotected and interacting with vehicles. While : pedestrian phases that are commonplace at most signalized intersections fa...

Automated Pedestrian Detection, Count and Analysis System

DOT National Transportation Integrated Search

2015-04-15

Pedestrian and bicycle count data is necessary for transportation planning, implementing safety countermeasures, and traffic management. This data is critical when evaluating the pedestrian level of service of safety (LOSS) and pedestrian safety perf...

Research of the relationship of pedestrian injury to collision speed, car-type, impact location and pedestrian sizes using human FE model (THUMS Version 4).

PubMed

Watanabe, Ryosuke; Katsuhara, Tadasuke; Miyazaki, Hiroshi; Kitagawa, Yuichi; Yasuki, Tsuyoshi

2012-10-01

Injuries in car to pedestrian collisions are affected by various factors such as the vehicle body type, pedestrian body size and impact location as well as the collision speed. This study aimed to investigate the influence of such factors taking a Finite Element (FE) approach. A total of 72 collision cases were simulated using three different vehicle FE models (Sedan, SUV, Mini-Van), three different pedestrian FE models (AM50, AF05, AM95), assuming two different impact locations (center and the corner of the bumper) and at four different collision speeds (20, 30, 40 and 50 km/h). The impact kinematics and the responses of the pedestrian model were validated against those in the literature prior to the simulations. The relationship between the collision speed and the predicted occurrence of head and chest injuries was examined for each case, analyzing the impact kinematics of the pedestrian against the vehicle body and resultant loading to the head and the chest. Strain based indicators were used in the simulation model to estimate skeletal injury (bony fracture) and soft tissue (brain and internal organs) injury. The study results primarily showed that the injury risk became higher with the collision speed, but was also affected by the combination of the factors such as the pedestrian size and the impact location. The study also discussed the injury patterns and trends with respect to the factors examined. In all of the simulated conditions, the model did not predict any severe injury at a collision speed of 20 km/h.

Jamming transitions induced by an attraction in pedestrian flow.

PubMed

Kwak, Jaeyoung; Jo, Hang-Hyun; Luttinen, Tapio; Kosonen, Iisakki

2017-08-01

We numerically study jamming transitions in pedestrian flow interacting with an attraction, mostly based on the social force model for pedestrians who can join the attraction. We formulate the joining probability as a function of social influence from others, reflecting that individual choice behavior is likely influenced by others. By controlling pedestrian influx and the social influence parameter, we identify various pedestrian flow patterns. For the bidirectional flow scenario, we observe a transition from the free flow phase to the freezing phase, in which oppositely walking pedestrians reach a complete stop and block each other. On the other hand, a different transition behavior appears in the unidirectional flow scenario, i.e., from the free flow phase to the localized jam phase and then to the extended jam phase. It is also observed that the extended jam phase can end up in freezing phenomena with a certain probability when pedestrian flux is high with strong social influence. This study highlights that attractive interactions between pedestrians and an attraction can trigger jamming transitions by increasing the number of conflicts among pedestrians near the attraction. In order to avoid excessive pedestrian jams, we suggest suppressing the number of conflicts under a certain level by moderating pedestrian influx especially when the social influence is strong.

Jamming transitions induced by an attraction in pedestrian flow

NASA Astrophysics Data System (ADS)

Kwak, Jaeyoung; Jo, Hang-Hyun; Luttinen, Tapio; Kosonen, Iisakki

2017-08-01

We numerically study jamming transitions in pedestrian flow interacting with an attraction, mostly based on the social force model for pedestrians who can join the attraction. We formulate the joining probability as a function of social influence from others, reflecting that individual choice behavior is likely influenced by others. By controlling pedestrian influx and the social influence parameter, we identify various pedestrian flow patterns. For the bidirectional flow scenario, we observe a transition from the free flow phase to the freezing phase, in which oppositely walking pedestrians reach a complete stop and block each other. On the other hand, a different transition behavior appears in the unidirectional flow scenario, i.e., from the free flow phase to the localized jam phase and then to the extended jam phase. It is also observed that the extended jam phase can end up in freezing phenomena with a certain probability when pedestrian flux is high with strong social influence. This study highlights that attractive interactions between pedestrians and an attraction can trigger jamming transitions by increasing the number of conflicts among pedestrians near the attraction. In order to avoid excessive pedestrian jams, we suggest suppressing the number of conflicts under a certain level by moderating pedestrian influx especially when the social influence is strong.

RECORDING DEVICE FOR 128 CHANNEL IONIZATION CHAMBERS (in Russian)

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

Goryunov, N.N.

1959-05-01

Descriptions are given of a 128-channel amplitude recording device desiged for operation with ionization chambers. Each channl has a large puse recording dynamic amplitude range (amplitudes can vary from each other up to 8000 fold). The recording of amplitudes is accomplished by photographing pulses on a cathode ray tube. With the aid of a commutation device it is possible to record 64 pulses simultaneously on one tube screen. (tr-auth)

Destiny-yield relationship for channel catfish reared in a biofloc technology production system

USDA-ARS?s Scientific Manuscript database

The effect of stocking density on yield of stocker channel catfish and water quality in a biofloc technology production system was studied in this completely randomized design experiment. Fingerling channel catfish (Ictalurus punctatus; 48.0 g/fish, 17.8 cm/fish) were stocked into nine continuously ...

The Safety of Older Pedestrians at Signal-Controlled Crossings.

ERIC Educational Resources Information Center

Harrell, W. Andrew

1996-01-01

Observes the extent to which pedestrians checked for oncoming traffic before crossing signal-controlled intersections on busy city streets. Pedestrians over the age of 50 were the most cautious, especially under dangerous traffic conditions. Older pedestrians were least likely to use other pedestrians as "guides" to safety, instead…

Identifying countermeasure strategies to increase safety of older pedestrians : traffic tech.

DOT National Transportation Integrated Search

2013-07-01

Pedestrian deaths accounted for 13% of all traffic fatalities : in 2010. While adults 65 and older made up 13% of the U.S. : population, they accounted for 19% of all pedestrian fatalities : in 2010. This age group is rapidly expanding in size : and ...

Understanding the conductive channel evolution in Na:WO3-x-based planar devices

NASA Astrophysics Data System (ADS)

Shang, Dashan; Li, Peining; Wang, Tao; Carria, Egidio; Sun, Jirong; Shen, Baogen; Taubner, Thomas; Valov, Ilia; Waser, Rainer; Wuttig, Matthias

2015-03-01

An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3-x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3-x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3-x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na+ mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3-x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3-x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3-x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the

Postirradiation behavior of p-channel charge-coupled devices irradiated at 153 K

NASA Astrophysics Data System (ADS)

Gow, Jason P. D.; Wood, Daniel; Murray, Neil J.; Burt, David; Hall, David J.; Dryer, Ben; Holland, Andrew D.

2016-04-01

The displacement damage hardness that can be achieved using p-channel charge-coupled devices (CCD) was originally demonstrated in 1997, and since then a number of other studies have demonstrated an improved tolerance to radiation-induced charge transfer inefficiency when compared to n-channel CCDs. A number of recent studies have also shown that the temperature history of the device after the irradiation impacts the performance of the detector, linked to the mobility of defects at different temperatures. The initial results from an e2v technologies p-channel CCD204 irradiated at 153 K with 10-MeV equivalent proton fluences of 1.24×109 and 1.24×1011 protons cm-2 is described. The dark current, cosmetic quality, and the number of defects identified using trap pumping immediately were monitored after the irradiation for a period of 150 h with the device held at 153 K and then after different periods of time at room temperature. The device also exhibited a flatband voltage shift of around 30 mV/krad, determined by the reduction in full well capacity.

Usability and Feasibility of an Internet-Based Virtual Pedestrian Environment to Teach Children to Cross Streets Safely

PubMed Central

Schwebel, David C.; McClure, Leslie A.; Severson, Joan

2013-01-01

Child pedestrian injury is a preventable global health challenge. Successful training efforts focused on child behavior, including individualized streetside training and training in large virtual pedestrian environments, are laborious and expensive. This study considers the usability and feasibility of a virtual pedestrian environment “game” application to teach children safe street-crossing behavior via the internet, a medium that could be broadly disseminated at low cost. Ten 7- and 8-year-old children participated. They engaged in an internet-based virtual pedestrian environment and completed a brief assessment survey. Researchers rated children's behavior while engaged in the game. Both self-report and researcher observations indicated the internet-based system was readily used by the children without adult support. The youth understood how to engage in the system and used it independently and attentively. The program also was feasible. It provided multiple measures of pedestrian safety that could be used for research or training purposes. Finally, the program was rated by children as engaging and educational. Researcher ratings suggested children used the program with minimal fidgeting or boredom. The pilot test suggests an internet-based virtual pedestrian environment offers a usable, feasible, engaging, and educational environment for child pedestrian safety training. If future research finds children learn the cognitive and perceptual skills needed to cross streets safely within it, internet-based training may provide a low-cost medium to broadly disseminate child pedestrian safety training. The concept may be generalized to other domains of health-related functioning such as teen driving safety, adolescent sexual risk-taking, and adolescent substance use. PMID:24678263

Second generation accessible pedestrian systems.

DOT National Transportation Integrated Search

2014-09-01

The Americans with Disabilities Act of 1990 has had a great impact on the implementation of Accessible Pedestrian Systems that target accessible and safety : impediments faced by pedestrians with mobility and visual impairments. Intersection geometri...

Does excessive daytime sleepiness affect children's pedestrian safety?

PubMed

Avis, Kristin T; Gamble, Karen L; Schwebel, David C

2014-02-01

Many cognitive factors contribute to unintentional pedestrian injury, including reaction time, impulsivity, risk-taking, attention, and decision-making. These same factors are negatively influenced by excessive daytime sleepiness (EDS), which may place children with EDS at greater risk for pedestrian injury. Using a case-control design, 33 children age 8 to 16 y with EDS from an established diagnosis of narcolepsy or idiopathic hypersomnia (IHS) engaged in a virtual reality pedestrian environment while unmedicated. Thirty-three healthy children matched by age, race, sex, and household income served as controls. Children with EDS were riskier pedestrians than healthy children. They were twice as likely to be struck by a virtual vehicle in the virtual pedestrian environment than healthy controls. Attentional skills of looking at oncoming traffic were not impaired among children with EDS, but decision-making for when to cross the street safely was significantly impaired. Results suggest excessive daytime sleepiness (EDS) from the clinical sleep disorders known as the hypersomnias of central origin may have significant consequences on children's daytime functioning in a critical domain of personal safety, pedestrian skills. Cognitive processes involved in safe pedestrian crossings may be impaired in children with EDS. In the pedestrian simulation, children with EDS appeared to show a pattern consistent with inattentional blindness, in that they "looked but did not process" information in their pedestrian environment. Results highlight the need for heightened awareness of potentially irreversible consequences of untreated sleep disorders and identify a possible target for pediatric injury prevention.

Does Excessive Daytime Sleepiness Affect Children's Pedestrian Safety?

PubMed Central

Avis, Kristin T.; Gamble, Karen L.; Schwebel, David C.

2014-01-01

Study Objectives: Many cognitive factors contribute to unintentional pedestrian injury, including reaction time, impulsivity, risk-taking, attention, and decision-making. These same factors are negatively influenced by excessive daytime sleepiness (EDS), which may place children with EDS at greater risk for pedestrian injury. Design, Participants, and Methods: Using a case-control design, 33 children age 8 to 16 y with EDS from an established diagnosis of narcolepsy or idiopathic hypersomnia (IHS) engaged in a virtual reality pedestrian environment while unmedicated. Thirty-three healthy children matched by age, race, sex, and household income served as controls. Results: Children with EDS were riskier pedestrians than healthy children. They were twice as likely to be struck by a virtual vehicle in the virtual pedestrian environment than healthy controls. Attentional skills of looking at oncoming traffic were not impaired among children with EDS, but decision-making for when to cross the street safely was significantly impaired. Conclusions: Results suggest excessive daytime sleepiness (EDS) from the clinical sleep disorders known as the hypersomnias of central origin may have significant consequences on children's daytime functioning in a critical domain of personal safety, pedestrian skills. Cognitive processes involved in safe pedestrian crossings may be impaired in children with EDS. In the pedestrian simulation, children with EDS appeared to show a pattern consistent with inattentional blindness, in that they “looked but did not process” information in their pedestrian environment. Results highlight the need for heightened awareness of potentially irreversible consequences of untreated sleep disorders and identify a possible target for pediatric injury prevention. Citation: Avis KT; Gamble KL; Schwebel DC. Does excessive daytime sleepiness affect children's pedestrian safety? SLEEP 2014;37(2):283-287. PMID:24497656

USDOT vehicle-to-pedestrian research : white paper.

DOT National Transportation Integrated Search

2017-02-06

Connecting vehicles with the surrounding infrastructure through Vehicle-to-Pedestrian (V2P) technology offers promise for addressing this challenge. For the past decade, the USDOT has been researching and testing a connected vehicle (CV) system where...

Experimental characterization of collision avoidance in pedestrian dynamics

NASA Astrophysics Data System (ADS)

Parisi, Daniel R.; Negri, Pablo A.; Bruno, Luciana

2016-08-01

In the present paper, the avoidance behavior of pedestrians was characterized by controlled experiments. Several conflict situations were studied considering different flow rates and group sizes in crossing and head-on configurations. Pedestrians were recorded from above, and individual two-dimensional trajectories of their displacement were recovered after image processing. Lateral swaying amplitude and step lengths were measured for free pedestrians, obtaining similar values to the ones reported in the literature. Minimum avoidance distances were computed in two-pedestrian experiments. In the case of one pedestrian dodging an arrested one, the avoidance distance did not depend on the relative orientation of the still pedestrian with respect to the direction of motion of the first. When both pedestrians were moving, the avoidance distance in a perpendicular encounter was longer than the one obtained during a head-on approach. It was found that the mean curvature of the trajectories was linearly anticorrelated with the mean speed. Furthermore, two common avoidance maneuvers, stopping and steering, were defined from the analysis of the acceleration and curvature in single trajectories. Interestingly, it was more probable to observe steering events than stopping ones, also the probability of simultaneous steering and stopping occurrences was negligible. The results obtained in this paper can be used to validate and calibrate pedestrian dynamics models.

Influence of material quality and process-induced defects on semiconductor device performance and yield

NASA Technical Reports Server (NTRS)

Porter, W. A.; Mckee, W. R.

1974-01-01

An overview of major causes of device yield degradation is presented. The relationships of device types to critical processes and typical defects are discussed, and the influence of the defect on device yield and performance is demonstrated. Various defect characterization techniques are described and applied. A correlation of device failure, defect type, and cause of defect is presented in tabular form with accompanying illustrations.

Use of a Hand-Held Personal Digital Assistant (PDA) to Self-Prompt Pedestrian Travel by Young Adults with Moderate Intellectual Disabilities

ERIC Educational Resources Information Center

Mechling, Linda C.; Seid, Nicole H.

2011-01-01

The purpose of this study was to evaluate use of a personal digital assistant (PDA) with picture, auditory, and video prompts as a portable self-prompting device to facilitate independent pedestrian travel by three high school age students with moderate intellectual disabilities. Using a multiple probe design across three destinations and their…

Using smartphone technology to deliver a virtual pedestrian environment: usability and validation.

PubMed

Schwebel, David C; Severson, Joan; He, Yefei

2017-09-01

Various programs effectively teach children to cross streets more safely, but all are labor- and cost-intensive. Recent developments in mobile phone technology offer opportunity to deliver virtual reality pedestrian environments to mobile smartphone platforms. Such an environment may offer a cost- and labor-effective strategy to teach children to cross streets safely. This study evaluated usability, feasibility, and validity of a smartphone-based virtual pedestrian environment. A total of 68 adults completed 12 virtual crossings within each of two virtual pedestrian environments, one delivered by smartphone and the other a semi-immersive kiosk virtual environment. Participants completed self-report measures of perceived realism and simulator sickness experienced in each virtual environment, plus self-reported demographic and personality characteristics. All participants followed system instructions and used the smartphone-based virtual environment without difficulty. No significant simulator sickness was reported or observed. Users rated the smartphone virtual environment as highly realistic. Convergent validity was detected, with many aspects of pedestrian behavior in the smartphone-based virtual environment matching behavior in the kiosk virtual environment. Anticipated correlations between personality and kiosk virtual reality pedestrian behavior emerged for the smartphone-based system. A smartphone-based virtual environment can be usable and valid. Future research should develop and evaluate such a training system.

Dual effects of pedestrian density on emergency evacuation

NASA Astrophysics Data System (ADS)

Ma, Yi; Lee, Eric Wai Ming; Yuen, Richard Kwok Kit

2017-02-01

This paper investigates the effect of the pedestrian density in building on the evacuation dynamic with simulation method. In the simulations, both the visibility in building and the exit limit of building are taken into account. The simulation results show that the effect of the pedestrian density in building on the evacuation dynamics is dual. On the one hand, when the visibility in building is very large, the increased pedestrian density plays a negative effect. On the other hand, when the visibility in building is very small, the increased pedestrian density can play a positive effect. The simulation results also show that when both the exit width and visibility are very small, the varying of evacuation time with regard to the pedestrian density is non-monotonous and presents a U-shaped tendency. That is, in this case, too large or too small pedestrian density in building is disadvantageous to the evacuation process. Our findings provide a new insight about the effect of the pedestrian density in building on the evacuation dynamic.

A Methodology for the Geometric Standardization of Vehicle Hoods to Compare Real-World Pedestrian Crashes

PubMed Central

Koetje, Bethany D.; Grabowski, Jurek G.

2008-01-01

This paper describes a standardization method that allows injury researchers to directly compare pedestrian hood contact points across a variety of hood sizes and geometries. To standardize hood contact locations a new coordinate system was created at the geometric center of the hood. Standardizing hood contact locations was done by turning each coordinate location into a ratio of the entire length or width of the hood. The standardized pedestrian contact locations could then be compared for various hood sizes. The standardized hood was divided into a three-by-three grid to aggregate contact points into hood regions. Data was obtained from the National Highway Traffic Safety Administration’s Pedestrian Crash Data Study from 1994 to 1998. To understand injury severity with respect to pedestrian hood contact location, the injuries were narrowed to the single most severe Abreviated Injury Scale injury to the pedestrian and hood location at which that injury was sustained. Of the 97 pedestrian/vehicle cases, pedestrians received 270 injuries from 141 unique hood contact locations. After standardization, 36%, 28%, 36% of all contact points were located on the left, center and right side of the hood respectively. Vertically, 26%, 45%, 28% of contacts occurred at the front, middle, and rear regions of the hood respectively. The middle passenger side of the hood contained the most number of AIS 3+ injuries. By using real-world crash data, engineers can make evidence based decisions to decease the severity of pedestrian injuries. PMID:19026236

Creating pedestrian crash scenarios in a driving simulator environment.

PubMed

Chrysler, Susan T; Ahmad, Omar; Schwarz, Chris W

2015-01-01

In 2012 in the United States, pedestrian injuries accounted for 3.3% of all traffic injuries but, disproportionately, pedestrian fatalities accounted for roughly 14% of traffic-related deaths (NHTSA 2014 ). In many other countries, pedestrians make up more than 50% of those injured and killed in crashes. This research project examined driver response to crash-imminent situations involving pedestrians in a high-fidelity, full-motion driving simulator. This article presents a scenario development method and discusses experimental design and control issues in conducting pedestrian crash research in a simulation environment. Driving simulators offer a safe environment in which to test driver response and offer the advantage of having virtual pedestrian models that move realistically, unlike test track studies, which by nature must use pedestrian dummies on some moving track. An analysis of pedestrian crash trajectories, speeds, roadside features, and pedestrian behavior was used to create 18 unique crash scenarios representative of the most frequent and most costly crash types. For the study reported here, we only considered scenarios where the car is traveling straight because these represent the majority of fatalities. We manipulated driver expectation of a pedestrian both by presenting intersection and mid-block crossing as well as by using features in the scene to direct the driver's visual attention toward or away from the crossing pedestrian. Three visual environments for the scenarios were used to provide a variety of roadside environments and speed: a 20-30 mph residential area, a 55 mph rural undivided highway, and a 40 mph urban area. Many variables of crash situations were considered in selecting and developing the scenarios, including vehicle and pedestrian movements; roadway and roadside features; environmental conditions; and characteristics of the pedestrian, driver, and vehicle. The driving simulator scenarios were subjected to iterative testing to

Warrants for pedestrian over and underpasses

DOT National Transportation Integrated Search

1984-07-01

The purpose of this research was to develop warrants for pedestrian over and underpasses or grade separated pedestrian crossings (GSPCs). Currently there are no established nationally acceptable warrants to serve as standards in deciding whether or n...

Conditions that influence drivers' yielding behavior at uncontrolled crossings and intersections with traffic signal controls.

DOT National Transportation Integrated Search

2015-08-31

There is a dearth of studies on how pedestrian who are blind might positively influence driver yielding in different travel situations. This project assessed common pedestrian behaviors (head turning, holding a cane, taking a step, holding up a hand,...

Pedestrian and bicycle accommodations on superstreets.

DOT National Transportation Integrated Search

2014-01-01

The objective of this research was to consider the unique challenges for pedestrians and bicyclists at superstreet intersections and : recommend crossing alternatives for both users. For pedestrians the options included the diagonal cross, median cro...

An Algorithm for Pedestrian Detection in Multispectral Image Sequences

NASA Astrophysics Data System (ADS)

Kniaz, V. V.; Fedorenko, V. V.

2017-05-01

The growing interest for self-driving cars provides a demand for scene understanding and obstacle detection algorithms. One of the most challenging problems in this field is the problem of pedestrian detection. Main difficulties arise from a diverse appearances of pedestrians. Poor visibility conditions such as fog and low light conditions also significantly decrease the quality of pedestrian detection. This paper presents a new optical flow based algorithm BipedDetet that provides robust pedestrian detection on a single-borad computer. The algorithm is based on the idea of simplified Kalman filtering suitable for realization on modern single-board computers. To detect a pedestrian a synthetic optical flow of the scene without pedestrians is generated using slanted-plane model. The estimate of a real optical flow is generated using a multispectral image sequence. The difference of the synthetic optical flow and the real optical flow provides the optical flow induced by pedestrians. The final detection of pedestrians is done by the segmentation of the difference of optical flows. To evaluate the BipedDetect algorithm a multispectral dataset was collected using a mobile robot.

Pedestrian detection based on redundant wavelet transform

NASA Astrophysics Data System (ADS)

Huang, Lin; Ji, Liping; Hu, Ping; Yang, Tiejun

2016-10-01

Intelligent video surveillance is to analysis video or image sequences captured by a fixed or mobile surveillance camera, including moving object detection, segmentation and recognition. By using it, we can be notified immediately in an abnormal situation. Pedestrian detection plays an important role in an intelligent video surveillance system, and it is also a key technology in the field of intelligent vehicle. So pedestrian detection has very vital significance in traffic management optimization, security early warn and abnormal behavior detection. Generally, pedestrian detection can be summarized as: first to estimate moving areas; then to extract features of region of interest; finally to classify using a classifier. Redundant wavelet transform (RWT) overcomes the deficiency of shift variant of discrete wavelet transform, and it has better performance in motion estimation when compared to discrete wavelet transform. Addressing the problem of the detection of multi-pedestrian with different speed, we present an algorithm of pedestrian detection based on motion estimation using RWT, combining histogram of oriented gradients (HOG) and support vector machine (SVM). Firstly, three intensities of movement (IoM) are estimated using RWT and the corresponding areas are segmented. According to the different IoM, a region proposal (RP) is generated. Then, the features of a RP is extracted using HOG. Finally, the features are fed into a SVM trained by pedestrian databases and the final detection results are gained. Experiments show that the proposed algorithm can detect pedestrians accurately and efficiently.

Evaluation of R1-6 gateway treatment alternatives for pedestrian crossings : follow-up report : final report.

DOT National Transportation Integrated Search

2017-06-01

Monthly follow-up data confirmed that permanent in roadway installations of the R1-6 gateway treatment led to an : increase in the percentage of drivers yielding to pedestrians at midblock and multilane urban and suburban locations : from 15% to 70% ...

Evaluation of geometrically personalized THUMS pedestrian model response against sedan-pedestrian PMHS impact test data.

PubMed

Chen, Huipeng; Poulard, David; Forman, Jason; Crandall, Jeff; Panzer, Matthew B

2018-07-04

Evaluating the biofidelity of pedestrian finite element models (PFEM) using postmortem human subjects (PMHS) is a challenge because differences in anthropometry between PMHS and PFEM could limit a model's capability to accurately capture cadaveric responses. Geometrical personalization via morphing can modify the PFEM geometry to match the specific PMHS anthropometry, which could alleviate this issue. In this study, the Total Human Model for Safety (THUMS) PFEM (Ver 4.01) was compared to the cadaveric response in vehicle-pedestrian impacts using geometrically personalized models. The AM50 THUMS PFEM was used as the baseline model, and 2 morphed PFEM were created to the anthropometric specifications of 2 obese PMHS used in a previous pedestrian impact study with a mid-size sedan. The same measurements as those obtained during the PMHS tests were calculated from the simulations (kinematics, accelerations, strains), and biofidelity metrics based on signals correlation (correlation and analysis, CORA) were established to compare the response of the models to the experiments. Injury outcomes were predicted deterministically (through strain-based threshold) and probabilistically (with injury risk functions) and compared with the injuries reported in the necropsy. The baseline model could not accurately capture all aspects of the PMHS kinematics, strain, and injury risks, whereas the morphed models reproduced biofidelic response in terms of trajectory (CORA score = 0.927 ± 0.092), velocities (0.975 ± 0.027), accelerations (0.862 ± 0.072), and strains (0.707 ± 0.143). The personalized THUMS models also generally predicted injuries consistent with those identified during posttest autopsy. The study highlights the need to control for pedestrian anthropometry when validating pedestrian human body models against PMHS data. The information provided in the current study could be useful for improving model biofidelity for vehicle-pedestrian impact scenarios.

Mean-field theory for pedestrian outflow through an exit.

PubMed

Yanagisawa, Daichi; Nishinari, Katsuhiro

2007-12-01

The average pedestrian flow through an exit is one of the most important indices in evaluating pedestrian dynamics. In order to study the flow in detail, the floor field model, which is a crowd model using cellular automata, is extended by taking into account realistic behavior of pedestrians around the exit. The model is studied by both numerical simulations and cluster analysis to obtain a theoretical expression for the average pedestrian flow through the exit. It is found quantitatively that the effects of exit door width, the wall, and the pedestrian mood of competition or cooperation significantly influence the average flow. The results show that there is a suitable width and position of the exit according to the pedestrians' mood.

Evaluating the Safety In Numbers effect for pedestrians at urban intersections.

PubMed

Murphy, Brendan; Levinson, David M; Owen, Andrew

2017-09-01

Assessment of collision risk between pedestrians and automobiles offers a powerful and informative tool in urban planning applications, and can be leveraged to inform proper placement of improvements and treatment projects to improve pedestrian safety. Such assessment can be performed using existing datasets of crashes, pedestrian counts, and automobile traffic flows to identify intersections or corridors characterized by elevated collision risks to pedestrians. The Safety In Numbers phenomenon, which refers to the observable effect that pedestrian safety is positively correlated with increased pedestrian traffic in a given area (i.e. that the individual per-pedestrian risk of a collision decreases with additional pedestrians), is a readily observed phenomenon that has been studied previously, though its directional causality is not yet known. A sample of 488 intersections in Minneapolis were analyzed, and statistically-significant log-linear relationships between pedestrian traffic flows and the per-pedestrian crash risk were found, indicating the Safety In Numbers effect. Potential planning applications of this analysis framework towards improving pedestrian safety in urban environments are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Shape memory alloy resetable spring lift for pedestrian protection

NASA Astrophysics Data System (ADS)

Barnes, Brian M.; Brei, Diann E.; Luntz, Jonathan E.; Strom, Kenneth; Browne, Alan L.; Johnson, Nancy

2008-03-01

Pedestrian protection has become an increasingly important aspect of automotive safety with new regulations taking effect around the world. Because it is increasingly difficult to meet these new regulations with traditional passive approaches, active lifts are being explored that increase the "crush zone" between the hood and rigid under-hood components as a means of mitigating the consequences of an impact with a non-occupant. Active lifts, however, are technically challenging because of the simultaneously high forces, stroke and quick timing resulting in most of the current devices being single use. This paper introduces the SMArt (Shape Memory Alloy ReseTable) Spring Lift, an automatically resetable and fully reusable device, which couples conventional standard compression springs to store the energy required for a hood lift, with Shape Memory Alloys actuators to achieve both an ultra high speed release of the spring and automatic reset of the system for multiple uses. Each of the four SMArt Device subsystems, lift, release, lower and reset/dissipate, are individually described. Two identical complete prototypes were fabricated and mounted at the rear corners of the hood, incorporated within a full-scale vehicle testbed at the SMARTT (Smart Material Advanced Research and Technology Transfer) lab at University of Michigan. Full operational cycle testing of a stationary vehicle in a laboratory setting confirms the ultrafast latch release, controlled lift profile, gravity lower to reposition the hood, and spring recompression via the ratchet engine successfully rearming the device for repeat cycles. While this is only a laboratory demonstration and extensive testing and development would be required for transition to a fielded product, this study does indicate that the SMArt Lift has promise as an alternative approach to pedestrian protection.

The correlation between pedestrian injury severity in real-life crashes and Euro NCAP pedestrian test results.

PubMed

Strandroth, Johan; Rizzi, Matteo; Sternlund, Simon; Lie, Anders; Tingvall, Claes

2011-12-01

The aim of the present study was to estimate the correlation between Euro NCAP pedestrian rating scores and injury outcome in real-life car-to-pedestrian crashes, with special focus on long-term disability. Another aim was to determine whether brake assist (BA) systems affect the injury outcome in real-life car-to-pedestrian crashes and to estimate the combined effects in injury reduction of a high Euro NCAP ranking score and BA. In the current study, the Euro NCAP pedestrian scoring was compared with the real-life outcome in pedestrian crashes that occurred in Sweden during 2003 to 2010. The real-life crash data were obtained from the data acquisition system Swedish Traffic Accident Data Acquisition (STRADA), which combines police records and hospital admission data. The medical data consisted of International Classification of Diseases (ICD) diagnoses and Abbreviated Injury Scale (AIS) scoring. In all, approximately 500 pedestrians submitted to hospital were included in the study. Each car model was coded according to Euro NCAP pedestrian scores. In addition, the presence or absence of BA was coded for each car involved. Cars were grouped according to their scoring. Injury outcomes were analyzed with AIS and, at the victim level, with permanent medical impairment. This was done by translating the injury scores for each individual to the risk of serious consequences (RSC) at 1, 5, and 10 percent risk of disability level. This indicates the total risk of a medical disability for each victim, given the severity and location of injuries. The mean RSC (mRSC) was then calculated for each car group and t-tests were conducted to falsify the null hypothesis at p ≤ .05 that the mRSC within the groups was equal. The results showed a significant reduction of injury severity for cars with better pedestrian scoring, although cars with a high score could not be studied due to lack of cases. The reduction in RSC for medium-performing cars in comparison with low-performing cars

Pedestrians' perceptions of walkability and safety in relation to the built environment in Cali, Colombia, 2009-10.

PubMed

Villaveces, Andrés; Nieto, Luis Alfonso; Ortega, Delia; Ríos, José Fernando; Medina, John Jairo; Gutiérrez, María Isabel; Rodríguez, Daniel

2012-10-01

To assess pedestrians' perceptions of the walkability of the urban environment and pedestrian safety in Cali, Colombia. Standardised intercept interviews were conducted of 400 pedestrians walking in 20 randomly selected urban zones to ascertain frequency of walking, and perceptions of safety, the built environment and security. Four focus group meetings were held with community members and students addressing these issues in an open-ended forum. The study analysed quantitative data collected in street interviews and qualitative information from focus groups addressing respondents' views on problems for pedestrians, how the built environment affects walking and ideal walking conditions. Access to public transportation was deemed the most positive characteristic of the built environment and 61% of respondents liked walking in the street. When disaggregating street conditions, the majority of pedestrians were dissatisfied with their walking experiences. Pedestrians cited lack of respect for norms, personal safety and built environment characteristics as their main concerns. Among frequent walkers, residents tended to rate their neighbourhoods more negatively compared with non-residents. Through qualitative interviews it became apparent that narrow sidewalks that are frequently obstructed by motor vehicles are a key reason for pedestrian dissatisfaction. A perception of overall insecurity further determines how pedestrians assess or modulate their walking in this city. Overall, walking in Cali was perceived negatively by pedestrians because of built environment characteristics and perceptions of insecurity. Qualitative information used to complement intercept surveys can provide a better way to identify pedestrian-specific transport-related problems.

Pedestrian injury causation parameters. Phase 2

DOT National Transportation Integrated Search

1981-10-01

This report describes data collection, quality control and data analysis procedures for a five-team program to study pedestrian injury causation factors. The data file contains 1,997 pedestrian accidents collected during a two and one-half year perio...

Flow boiling with enhancement devices for cold plate coolant channel design

NASA Technical Reports Server (NTRS)

Boyd, Ronald D., Sr.

1989-01-01

A research program to study the effect of enhancement devices on flow boiling heat transfer in coolant channels, which are heated either from the top side or uniformly, is discussed. Freon 11 is the working fluid involved. The specific objectives are: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls, (2) examine the effect channel diameter (and the length-to-diameter aspect ratio) variations for the smooth wall channel, and (3) develop an improved data reduction analysis.

Guide for Maintaining Pedestrian Facilities for Enhanced Safety.

DOT National Transportation Integrated Search

2013-10-01

A Guide for Maintaining Pedestrian Facilities for Enhanced Safety provides guidance for maintaining pedestrian facilities with the primary goal of increasing safety and mobility. The Guide addresses the needs for pedestrian facility maintenance; comm...

The effect of flow data resolution on sediment yield estimation and channel design

NASA Astrophysics Data System (ADS)

Rosburg, Tyler T.; Nelson, Peter A.; Sholtes, Joel S.; Bledsoe, Brian P.

2016-07-01

The decision to use either daily-averaged or sub-daily streamflow records has the potential to impact the calculation of sediment transport metrics and stream channel design. Using bedload and suspended load sediment transport measurements collected at 138 sites across the United States, we calculated the effective discharge, sediment yield, and half-load discharge using sediment rating curves over long time periods (median record length = 24 years) with both daily-averaged and sub-daily streamflow records. A comparison of sediment transport metrics calculated with both daily-average and sub-daily stream flow data at each site showed that daily-averaged flow data do not adequately represent the magnitude of high stream flows at hydrologically flashy sites. Daily-average stream flow data cause an underestimation of sediment transport and sediment yield (including the half-load discharge) at flashy sites. The degree of underestimation was correlated with the level of flashiness and the exponent of the sediment rating curve. No consistent relationship between the use of either daily-average or sub-daily streamflow data and the resultant effective discharge was found. When used in channel design, computed sediment transport metrics may have errors due to flow data resolution, which can propagate into design slope calculations which, if implemented, could lead to unwanted aggradation or degradation in the design channel. This analysis illustrates the importance of using sub-daily flow data in the calculation of sediment yield in urbanizing or otherwise flashy watersheds. Furthermore, this analysis provides practical charts for estimating and correcting these types of underestimation errors commonly incurred in sediment yield calculations.

Evaluation of R1-6 gateway treatment alternatives for pedestrian crossings : follow-up report : draft report.

DOT National Transportation Integrated Search

2016-12-01

Monthly follow-up data confirmed that permanent in roadway installations of the R1-6 gateway treatment led to an increase in the percentage of drivers yielding to pedestrians at midblock and multilane urban and suburban locations from 15% to 70% and ...

Understanding the conductive channel evolution in Na:WO(3-x)-based planar devices.

PubMed

Shang, Dashan; Li, Peining; Wang, Tao; Carria, Egidio; Sun, Jirong; Shen, Baogen; Taubner, Thomas; Valov, Ilia; Waser, Rainer; Wuttig, Matthias

2015-04-14

An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO(3-x)) films on a soda-lime glass substrate, from which Na(+) diffuses into the WO(3-x) films during the deposition. The entire process of Na(+) migration driven by an alternating electric field is visualized in the Na-doped WO(3-x) films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na(+) mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.

Pedestrian Detection by Laser Scanning and Depth Imagery

NASA Astrophysics Data System (ADS)

Barsi, A.; Lovas, T.; Molnar, B.; Somogyi, A.; Igazvolgyi, Z.

2016-06-01

Pedestrian flow is much less regulated and controlled compared to vehicle traffic. Estimating flow parameters would support many safety, security or commercial applications. Current paper discusses a method that enables acquiring information on pedestrian movements without disturbing and changing their motion. Profile laser scanner and depth camera have been applied to capture the geometry of the moving people as time series. Procedures have been developed to derive complex flow parameters, such as count, volume, walking direction and velocity from laser scanned point clouds. Since no images are captured from the faces of pedestrians, no privacy issues raised. The paper includes accuracy analysis of the estimated parameters based on video footage as reference. Due to the dense point clouds, detailed geometry analysis has been conducted to obtain the height and shoulder width of pedestrians and to detect whether luggage has been carried or not. The derived parameters support safety (e.g. detecting critical pedestrian density in mass events), security (e.g. detecting prohibited baggage in endangered areas) and commercial applications (e.g. counting pedestrians at all entrances/exits of a shopping mall).

Features of the Vision of Elderly Pedestrians when Crossing a Road.

PubMed

Matsui, Yasuhiro; Oikawa, Shoko; Aoki, Yoshio; Sekine, Michiaki; Mitobe, Kazutaka

2014-11-01

The present study clarifies the mechanism by which an accident occurs when an elderly pedestrian crosses a road in front of a car, focusing on features of the central and peripheral vision of elderly pedestrians who are judging when it is safe to cross the road. For the pedestrian's central visual field, we investigated the effect of age on the timing judgment using an actual car. The results for daytime conditions indicate that the elderly pedestrians tended to make later judgments of when they crossed the road from the right side of the driver's view at high car velocities. At night, for a car with its headlights on high beam, the average car-pedestrian distances of elderly pedestrians on the left side of the driver's view were significantly longer than those of young pedestrians at velocities of 20 and 40 km/h. The eyesight of the elderly pedestrians during the day did not affect the timing judgment of crossing a road. At night, for a car with its headlights on either high or low beam, the average car-pedestrian distances of elderly pedestrians having good eyesight were longer than those of elderly pedestrians having poor eyesight, for all car velocities. The color of the car body in the central visual field did not affect the timing judgment of elderly pedestrians crossing the road. Meanwhile, the car-body color in the elderly pedestrian's peripheral vision strongly affected the pedestrian's awareness of the car.

Elderly Pedestrian Safety and Driver Distractions

DOT National Transportation Integrated Search

2015-12-16

About two-thirds of pedestrian fatalities in Maine involve people crossing urban streets or rural roads. Therefore, providing safe sidewalks is not a cure-all even if that is what many pedestrians ask for. We also need to improve safety at crosswalks...

New insights into turbulent pedestrian movement pattern in crowd-quakes

NASA Astrophysics Data System (ADS)

Ma, J.; Song, W. G.; Lo, S. M.; Fang, Z. M.

2013-02-01

Video recordings right before the Love Parade disaster have been quantitatively analyzed to explore the bursts of unusual crowd movement patterns, crowd-quakes. The pedestrian movement pattern in this incident was special for the reason that it happened in a congested counter flow scenario, where stopped pedestrians were involved. No one was believed to have pushed others intentionally at the beginning, however, under this situation, the body contacts among the pedestrians still induced a force spread, which then led to velocity fluctuation. As indicated by the individual velocity-related features, the densely crowded pedestrian movement displayed turbulent flow features. Further analyzing the overall flow field, we also found that the pedestrian flow field shared typical patterns with turbulent fluid flow. As a result of the turbulent state, different clusters of pedestrians displayed different velocity features. Thus crowd pressure which took into account the velocity and density information was proved to be a good indicator of crowd disasters. Based on these essential features of pedestrian crowd-quakes, a minimal model, i.e., a pedestrian crowd-quake model, was established. Effects including pedestrian gait, stress conservation level and personal intention to escape were explored.

An Analysis of Distance from Collision Site to Pedestrian Residence in Pedestrian versus Automobile Collisions Presenting to a Level 1 Trauma Center.

PubMed

Anderson, Craig L; Dominguez, Kathlynn M; Hoang, Teresa V; Rowther, Armaan Ahmed; Carroll, M Christy; Lotfipour, Shahram; Hoonpongsimanont, Wirachin; Chakravarthy, Bharath

2012-01-01

This study tests the hypothesis that most pedestrian collisions occur near victims' homes. Patients involved in automobile versus pedestrian collisions who presented to the emergency department at a Level I trauma center between January 2000 and December 2009 were included in the study. Patient demographics were obtained from the trauma registry. Home address was determined from hospital records, collision site was determined from the paramedic run sheet, and the shortest walking distance between the collision site and pedestrian residence was determined using Google Maps. We summarized distances for groups with the median and compared groups using the Kruskal-Wallis rank test. We identified 1917 pedestrian injury cases and identified both residence address and collision location for 1213 cases (63%). Forty-eight percent of the collisions were near home (within 1.1 km, 95% CI 45-51%). Median distance from residence to collision site was 1.4 km (interquartile range 0.3-7.4 km). For ages 0-17, the median distance 0.7 km, and 59% (95% CI 54-63%) of collisions occurred near home. For ages 65 and older, the median distance was 0.6 km and 65% (95% CI 55-73%) were injured near home. Distance did not differ by sex, race, ethnicity, or blood alcohol level. More severe injuries (Injury Severity Score ≥ 16) occurred further from home than less severe injuries (median 1.9 km vs. 1.3 km, p=.01). Patients with a hospital stay of 3 days or less were injured closer to home (median 1.3 km) than patients with a hospital stay of 4 days or more (median 1.8 km, p=.001). Twenty-two percent were injured within the same census tract as their home, 22% on the boundary of their home census tract, and 55% in a different census tract.

Highway Safety Program Manual: Volume 14: Pedestrian Safety.

ERIC Educational Resources Information Center

National Highway Traffic Safety Administration (DOT), Washington, DC.

Volume 14 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) concentrates on pedestrian safety. The purpose and objectives of a pedestrian safety program are outlined. Federal authority in the area of pedestrian safety and policies regarding a safety program…

Pedestrians' crossing behaviors and safety at unmarked roadway in China.

PubMed

Zhuang, Xiangling; Wu, Changxu

2011-11-01

Pedestrians' crossing out of crosswalks (unmarked roadway) contributed to many traffic accidents, but existing pedestrian studies mainly focus on crosswalk crossing in developed countries specifically. Field observation of 254 pedestrians at unmarked roadway in China showed that 65.7% of them did not look for vehicles after arriving at the curb. Those who did look and pay attention to the traffic did so for duration of time that followed an exponential distribution. Pedestrians preferred crossing actively in tentative ways rather than waiting passively. The waiting time at the curb, at the median, and at the roadway all followed exponential distributions. During crossing, all pedestrians looked at the oncoming vehicles. When interacting with these vehicles, 31.9% of them ran and 11.4% stepped backwards. Running pedestrians usually began running at the borderline rather than within the lanes. Pedestrians preferred safe to short paths and they crossed second half of the road with significantly higher speed. These behavioral patterns were rechecked at an additional site with 105 pedestrians and the results showed much accordance. In terms of safety, pedestrians who were middle aged, involved in bigger groups, looked at vehicles more often before crossing or interacted with buses rather than cars were safer while those running were more dangerous. Potential applications of these findings, including building accurate simulation models of pedestrians and education of drivers and pedestrians in developing countries were also discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

How to decrease pedestrian injuries: conceptual evolutions starting from 137 crash tests.

PubMed

Thollon, Lionel; Jammes, Christian; Behr, Michel; Arnoux, Pierre-Jean; Cavallero, Claude; Brunet, Christian

2007-02-01

The improvement of vulnerable users' protection has become an essential objective for our society. Injury assessments observed in clinical traumatology have led researchers and manufacturers to understand the mechanisms involved and to design safe vehicles (to reduce the severity of pedestrian injuries). In all, 137 crash tests between 1979 and 2004 with postmortal human subjects (PMHS) were performed at the Laboratory of Applied Biomechanics to access pedestrian protection. A retrospective analysis of these experimental tests, pedestrian/car impacts (full scale or subsystems), performed at the laboratory is thus proposed. This document focuses on injury mechanisms investigation on the evolution of the experimental approach, as well as on the vehicles' technological improvements performed by car manufacturers. The analysis of experimental results (injury assessment, kinematics, vehicle deformations, etc.) shows the complexity and variety of injury mechanisms. The injury assessment shows the need to improve lower-limb joints protection, as well as head and spine segments, because of the difficulties of surgical repair of these injuries. Experimental tests contribute to evaluate the automobile safety evolution in the field of pedestrian protection. The main induced car improvements concern considerable efforts on vehicle material behavior and their capacity to dissipate energy during shocks (replacement of the convex rigid bumpers by deformable structures, modification of the windscreen structure). They also concern the suppression of all aggressive structures for the pedestrian (spare wheel initially placed on the front part of the vehicle, protection of the heels of windscreen wiper, etc.).

The Advocacy for Pedestrian Safety Study: Cluster Randomised Trial Evaluating a Political Advocacy Approach to Reduce Pedestrian Injuries in Deprived Communities

PubMed Central

Lyons, Ronan A.; Kendrick, Denise; Towner, Elizabeth M. L.; Coupland, Carol; Hayes, Mike; Christie, Nicola; Sleney, Judith; Jones, Sarah; Kimberlee, Richard; Rodgers, Sarah E.; Turner, Samantha; Brussoni, Mariana; Vinogradova, Yana; Sarvotham, Tinnu; Macey, Steven

2013-01-01

Objective To determine whether advocacy targeted at local politicians leads to action to reduce the risk of pedestrian injury in deprived areas. Design Cluster randomised controlled trial. Setting 239 electoral wards in 57 local authorities in England and Wales. Participants 617 elected local politicians. Interventions Intervention group politicians were provided with tailored information packs, including maps of casualty sites, numbers injured and a synopsis of effective interventions. Main outcome measures 25–30 months post intervention, primary outcomes included: electoral ward level: percentage of road traffic calmed; proportion with new interventions; school level: percentage with 20 mph zones, Safe Routes to School, pedestrian training or road safety education; politician level: percentage lobbying for safety measures. Secondary outcomes included politicians’ interest and involvement in injury prevention, and facilitators and barriers to implementation. Results Primary outcomes did not significantly differ: % difference in traffic calming (0.07, 95%CI: −0.07 to 0.20); proportion of schools with 20 mph zones (RR 1.47, 95%CI: 0.93 to 2.32), Safe Routes to School (RR 1.34, 95%CI: 0.83 to 2.17), pedestrian training (RR 1.23, 95%CI: 0.95 to 1.61) or other safety education (RR 1.16, 95%CI: 0.97 to 1.39). Intervention group politicians reported greater interest in child injury prevention (RR 1.09, 95%CI 1.03 to 1.16), belief in potential to help prevent injuries (RR 1.36, 95%CI 1.16 to 1.61), particularly pedestrian safety (RR 1.55, 95%CI 1.19 to 2.03). 63% of intervention politicians reported supporting new pedestrian safety schemes. The majority found the advocacy information surprising, interesting, effectively presented, and could identify suitable local interventions. Conclusions This study demonstrates the feasibility of an innovative approach to translational public health by targeting local politicians in a randomised controlled trial. The intervention

Analysis of Hanle-effect signals observed in Si-channel spin accumulation devices

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

Takamura, Yota, E-mail: takamura@spin.pe.titech.ac.jp; Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552; Akushichi, Taiju

2014-05-07

We reexamined curve-fitting analysis for spin-accumulation signals observed in Si-channel spin-accumulation devices, employing widely-used Lorentz functions and a new formula developed from the spin diffusion equation. A Si-channel spin-accumulation device with a high quality ferromagnetic spin injector was fabricated, and its observed spin-accumulation signals were verified. Experimentally obtained Hanle-effect signals for spin accumulation were not able to be fitted by a single Lorentz function and were reproduced by the newly developed formula. Our developed formula can represent spin-accumulation signals and thus analyze Hanle-effect signals.

Impact of Transit Stop Location on Pedestrian Safety [Summary

DOT National Transportation Integrated Search

2017-11-01

Pedestrians can be vulnerable in many roadway situations so pedestrian safety and reducing pedestrian collisions are always a high priority for the Florida Department of Transportation (FDOT). As more people use public transportation to get from home...

North Carolina pedestrian crossing guidance : final report.

DOT National Transportation Integrated Search

2015-07-20

This research report is geared at providing guidance to NCDOT for when to consider marking crosswalks at : uncontrolled approaches for pedestrians, installing pedestrian signal heads at existing signalized intersections, or : providing supplemental t...

Analyzing fault in pedestrian-motor vehicle crashes in North Carolina.

PubMed

Ulfarsson, Gudmundur F; Kim, Sungyop; Booth, Kathleen M

2010-11-01

Crashes between pedestrians and motor vehicles are an important traffic safety concern. This paper explores the assignment of fault in such crashes, where observed factors are associated with pedestrian at fault, driver at fault, or both at fault. The analysis is based on police reported crash data for 1997 through 2000 in North Carolina, U.S.A. The results show that pedestrians are found at fault in 59% of the crashes, drivers in 32%, and both are found at fault in 9%. The results indicate drivers need to take greater notice of pedestrians when drivers are turning, merging, and backing up as these are some of the prime factors associated with the driver being found at fault in a crash. Pedestrians must apply greater caution when crossing streets, waiting to cross, and when walking along roads, as these are correlated with pedestrians being found at fault. The results suggest a need for campaigns focused on positively affecting pedestrian street-crossing behavior in combination with added jaywalking enforcement. The results also indicate that campaigns to increase the use of pedestrian visibility improvements at night can have a significant positive impact on traffic safety. Intoxication is a concern and the results show that it is not only driver intoxication that is affecting safety, but also pedestrian intoxication. The findings show in combination with other research in the field, that results from traffic safety studies are not necessarily transferable between distant geographic locations, and that location-specific safety research needs to take place. It is also important to further study the specific effects of the design of the pedestrian environment on safety, e.g. crosswalk spacing, signal timings, etc., which together may affect pedestrian safety and pedestrian behavior. 2010 Elsevier Ltd. All rights reserved.

Close to real-time robust pedestrian detection and tracking

NASA Astrophysics Data System (ADS)

Lipetski, Y.; Loibner, G.; Sidla, O.

2015-03-01

Fully automated video based pedestrian detection and tracking is a challenging task with many practical and important applications. We present our work aimed to allow robust and simultaneously close to real-time tracking of pedestrians. The presented approach is stable to occlusions, lighting conditions and is generalized to be applied on arbitrary video data. The core tracking approach is built upon tracking-by-detections principle. We describe our cascaded HOG detector with successive CNN verification in detail. For the tracking and re-identification task, we did an extensive analysis of appearance based features as well as their combinations. The tracker was tested on many hours of video data for different scenarios; the results are presented and discussed.

Wi-Fi/MARG Integration for Indoor Pedestrian Localization.

PubMed

Tian, Zengshan; Jin, Yue; Zhou, Mu; Wu, Zipeng; Li, Ze

2016-12-10

With the wide deployment of Wi-Fi networks, Wi-Fi based indoor localization systems that are deployed without any special hardware have caught significant attention and have become a currently practical technology. At the same time, the Magnetic, Angular Rate, and Gravity (MARG) sensors installed in commercial mobile devices can achieve highly-accurate localization in short time. Based on this, we design a novel indoor localization system by using built-in MARG sensors and a Wi-Fi module. The innovative contributions of this paper include the enhanced Pedestrian Dead Reckoning (PDR) and Wi-Fi localization approaches, and an Extended Kalman Particle Filter (EKPF) based fusion algorithm. A new Wi-Fi/MARG indoor localization system, including an Android based mobile client, a Web page for remote control, and a location server, is developed for real-time indoor pedestrian localization. The extensive experimental results show that the proposed system is featured with better localization performance, with the average error 0.85 m, than the one achieved by using the Wi-Fi module or MARG sensors solely.

Wi-Fi/MARG Integration for Indoor Pedestrian Localization

PubMed Central

Tian, Zengshan; Jin, Yue; Zhou, Mu; Wu, Zipeng; Li, Ze

2016-01-01

With the wide deployment of Wi-Fi networks, Wi-Fi based indoor localization systems that are deployed without any special hardware have caught significant attention and have become a currently practical technology. At the same time, the Magnetic, Angular Rate, and Gravity (MARG) sensors installed in commercial mobile devices can achieve highly-accurate localization in short time. Based on this, we design a novel indoor localization system by using built-in MARG sensors and a Wi-Fi module. The innovative contributions of this paper include the enhanced Pedestrian Dead Reckoning (PDR) and Wi-Fi localization approaches, and an Extended Kalman Particle Filter (EKPF) based fusion algorithm. A new Wi-Fi/MARG indoor localization system, including an Android based mobile client, a Web page for remote control, and a location server, is developed for real-time indoor pedestrian localization. The extensive experimental results show that the proposed system is featured with better localization performance, with the average error 0.85 m, than the one achieved by using the Wi-Fi module or MARG sensors solely. PMID:27973412

Effectiveness and efficiencies in pedestrian safety.

DOT National Transportation Integrated Search

1982-03-01

Pedestrian fatalities constitute 16 percent of total highway - related fatalities. Excluding motor vehicle occupants, pedestrians comprise the target single category of fatalities on the nation's streets and highways. A total of 85 percent of ! all p...

Velocity Vector Field Visualization of Flow in Liquid Acquisition Device Channel

NASA Technical Reports Server (NTRS)

McQuillen, John B.; Chao, David F.; Hall, Nancy R.; Zhang, Nengli

2012-01-01

A capillary flow liquid acquisition device (LAD) for cryogenic propellants has been developed and tested in NASA Glenn Research Center to meet the requirements of transferring cryogenic liquid propellants from storage tanks to an engine in reduced gravity environments. The prototypical mesh screen channel LAD was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations at different liquid submersion depths of the screen channel LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel was undertaken. The resulting velocity vector field visualization for the flow in the channel has been used to reveal the gravity effects on the flow in the screen channel.

Automated pedestrian counter : final report, February 2010.

DOT National Transportation Integrated Search

2010-02-01

Emerging sensor technologies accelerated the shift toward automatic pedestrian counting methods to : acquire reliable long-term data for transportation design, planning, and safety studies. Although a : number of commercial pedestrian sensors are ava...

Necessity of guides in pedestrian emergency evacuation

NASA Astrophysics Data System (ADS)

Yang, Xiaoxia; Dong, Hairong; Yao, Xiuming; Sun, Xubin; Wang, Qianling; Zhou, Min

2016-01-01

The role of guide who is in charge of leading pedestrians to evacuate in the case of emergency plays a critical role for the uninformed people. This paper first investigates the influence of mass behavior on evacuation dynamics and mainly focuses on the guided evacuation dynamics. In the extended crowd model proposed in this paper, individualistic behavior, herding behavior and environment influence are all considered for pedestrians who are not informed by the guide. According to the simulation results, herding behavior makes more pedestrians evacuate from the room in the same period of time. Besides, guided crowd demonstrates the same behavior of group dynamics which is characterized by gathering, conflicts and balance. Moreover, simulation results indicate guides with appropriate initial positions and quantity are more conducive to evacuation under a moderate initial density of pedestrians.

Multi-level hot zone identification for pedestrian safety.

PubMed

Lee, Jaeyoung; Abdel-Aty, Mohamed; Choi, Keechoo; Huang, Helai

2015-03-01

According to the National Highway Traffic Safety Administration (NHTSA), while fatalities from traffic crashes have decreased, the proportion of pedestrian fatalities has steadily increased from 11% to 14% over the past decade. This study aims at identifying two zonal levels factors. The first is to identify hot zones at which pedestrian crashes occurs, while the second are zones where crash-involved pedestrians came from. Bayesian Poisson lognormal simultaneous equation spatial error model (BPLSESEM) was estimated and revealed significant factors for the two target variables. Then, PSIs (potential for safety improvements) were computed using the model. Subsequently, a novel hot zone identification method was suggested to combine both hot zones from where vulnerable pedestrians originated with hot zones where many pedestrian crashes occur. For the former zones, targeted safety education and awareness campaigns can be provided as countermeasures whereas area-wide engineering treatments and enforcement may be effective safety treatments for the latter ones. Thus, it is expected that practitioners are able to suggest appropriate safety treatments for pedestrian crashes using the method and results from this study. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vehicular camera pedestrian detection research

NASA Astrophysics Data System (ADS)

Liu, Jiahui

2018-03-01

With the rapid development of science and technology, it has made great development, but at the same time of highway traffic more convenient in highway traffic and transportation. However, in the meantime, traffic safety accidents occur more and more frequently in China. In order to deal with the increasingly heavy traffic safety. So, protecting the safety of people's personal property and facilitating travel has become a top priority. The real-time accurate pedestrian and driving environment are obtained through a vehicular camera which are used to detection and track the preceding moving targets. It is popular in the domain of intelligent vehicle safety driving, autonomous navigation and traffic system research. Based on the pedestrian video obtained by the Vehicular Camera, this paper studies the trajectory of pedestrian detection and its algorithm.

Calibrating cellular automaton models for pedestrians walking through corners

NASA Astrophysics Data System (ADS)

Dias, Charitha; Lovreglio, Ruggiero

2018-05-01

Cellular Automata (CA) based pedestrian simulation models have gained remarkable popularity as they are simpler and easier to implement compared to other microscopic modeling approaches. However, incorporating traditional floor field representations in CA models to simulate pedestrian corner navigation behavior could result in unrealistic behaviors. Even though several previous studies have attempted to enhance CA models to realistically simulate pedestrian maneuvers around bends, such modifications have not been calibrated or validated against empirical data. In this study, two static floor field (SFF) representations, namely 'discrete representation' and 'continuous representation', are calibrated for CA-models to represent pedestrians' walking behavior around 90° bends. Trajectory data collected through a controlled experiment are used to calibrate these model representations. Calibration results indicate that although both floor field representations can represent pedestrians' corner navigation behavior, the 'continuous' representation fits the data better. Output of this study could be beneficial for enhancing the reliability of existing CA-based models by representing pedestrians' corner navigation behaviors more realistically.

1995 Bicycle and Pedestrian Safety Report

DOT National Transportation Integrated Search

1995-03-01

This report provides a review of the current data on bicycle and pedestrian : safety across the United States, finding that safety and education : programs could significantly improve bicycle and pedestrian safety in the : Dallas-Fort Worth Metropoli...

Separation control by vortex generator devices in a transonic channel flow

NASA Astrophysics Data System (ADS)

Bur, Reynald; Coponet, Didier; Carpels, Yves

2009-12-01

An experimental study was conducted in a transonic channel to control by mechanical vortex generator devices the strong interaction between a shock wave and a separated turbulent boundary layer. Control devices—co-rotating and counter-rotating vane-type vortex generators—were implemented upstream of the shock foot region and tested both on a steady shock wave and on a forced shock oscillation configurations. The spanwise spacing of vortex generator devices along the channel appeared to be an important parameter to control the flow separation region. When the distance between each device is decreased, the vortices merging is more efficient to reduce the separation. Their placement upstream of the shock wave is determinant to ensure that vortices have mixed momentum all spanwise long before they reach the separation line, so as to avoid separation cells. Then, vortex generators slightly reduced the amplitude of the forced shock wave oscillation by delaying the upstream displacement of the leading shock.

Impact of pedestrian malls on transportation activities.

DOT National Transportation Integrated Search

1979-01-01

Pedestrian malls - streets that have been dedicated to pedestrian use only - are a popular urban renewal tactic for stimulating economic growth in deteriorating central business districts by attracting commercial retail business. Because of benefits ...

Pedestrian Crossings. USMES Teacher Resource Book.

ERIC Educational Resources Information Center

Brady, Ray, Jr., Ed.; Arbetter, Carolyn Clinton, Ed.

This USMES unit challenges students to recommend and try to have a change made which would improve the safety and convenience of a pedestrian crossing near the school. The teacher resource book for the Pedestrian Crossings unit contains five sections. The first section describes the USMES approach to student-initiated investigations of real…

A study of pedestrian compliance with traffic signals for exclusive and concurrent phasing.

PubMed

Ivan, John N; McKernan, Kevin; Zhang, Yaohua; Ravishanker, Nalini; Mamun, Sha A

2017-01-01

This paper describes a comparison of pedestrian compliance at traffic signals with two types of pedestrian phasing: concurrent, where both pedestrians and vehicular traffic are directed to move in the same directions at the same time, and exclusive, where pedestrians are directed to move during their own dedicated phase while all vehicular traffic is stopped. Exclusive phasing is usually perceived to be safer, especially by senior and disabled advocacy groups, although these safety benefits depend upon pedestrians waiting for the walk signal. This paper investigates whether or not there are differences between pedestrian compliance at signals with exclusive pedestrian phasing and those with concurrent phasing and whether these differences continue to exist when compliance at exclusive phasing signals is evaluated as if they had concurrent phasing. Pedestrian behavior was observed at 42 signalized intersections in central Connecticut with both concurrent and exclusive pedestrian phasing. Binary regression models were estimated to predict pedestrian compliance as a function of the pedestrian phasing type and other intersection characteristics, such as vehicular and pedestrian volume, crossing distance and speed limit. We found that pedestrian compliance is significantly higher at intersections with concurrent pedestrian phasing than at those with exclusive pedestrian phasing, but this difference is not significant when compliance at exclusive phase intersections is evaluated as if it had concurrent phasing. This suggests that pedestrians treat exclusive phase intersections as though they have concurrent phasing, rendering the safety benefits of exclusive pedestrian phasing elusive. No differences were observed for senior or non-senior pedestrians. Published by Elsevier Ltd.

Flow boiling with enhancement devices for cold plate coolant channel design

NASA Technical Reports Server (NTRS)

Boyd, Ronald D.; Turknett, Jerry C.; Smith, Alvin

1989-01-01

The effects of enhancement devices on flow boiling heat transfer in circular coolant channels, which are heated over a fraction of their perimeters, are studied. The variations were examined in both the mean and local (axial, and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls. Improvements were initiated in the present data reduction analysis. These efforts should lead to the development of heat transfer correlations which include effects of single side heat flux and enhancement device configuration. It is hoped that a stage will be set for the study of heat transfer and pressure drop in single sided heated systems under zero gravity conditions.

Simulated interactions of pedestrian crossings and motorized vehicles in residential areas

NASA Astrophysics Data System (ADS)

Wang, Yan; Peng, Zhongyi; Chen, Qun

2018-01-01

To evaluate whether motorized vehicles can travel through a residential area, this paper develops a cellular automata (CA) model to simulate the interactions between pedestrian crossings and motorized vehicles in a residential area. In this paper, pedestrians determine their crossing speed according to their judgments of the position and velocity of the upcoming vehicles. The pedestrians may walk slowly or quickly or even run, and the pedestrian crossing time influences the vehicle movement. In addition, the proposed model considers the safety margin time needed for pedestrians to cross, and pedestrian-vehicle conflict is considered using the vehicle collision avoidance rule. Through simulations of interactions of pedestrian crossings with motorized vehicles' movement on a typical road in a residential area, the average wait time for pedestrians to cross and the average vehicle velocity under different pedestrian crossing volumes, different vehicle flows and different maximum vehicle velocities are obtained. To avoid an excessive waiting time for pedestrians to cross, the vehicle flow should be less than 180 veh/h, which allows an average of less than 10 s of waiting time; if the vehicle flow rate is less than 36 veh/h, then the waiting time is approximately 1 s. Field observations are conducted to validate the simulation results.

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.

Modelling Pedestrian Travel Time and the Design of Facilities: A Queuing Approach

PubMed Central

Rahman, Khalidur; Abdul Ghani, Noraida; Abdulbasah Kamil, Anton; Mustafa, Adli; Kabir Chowdhury, Md. Ahmed

2013-01-01

Pedestrian movements are the consequence of several complex and stochastic facts. The modelling of pedestrian movements and the ability to predict the travel time are useful for evaluating the performance of a pedestrian facility. However, only a few studies can be found that incorporate the design of the facility, local pedestrian body dimensions, the delay experienced by the pedestrians, and level of service to the pedestrian movements. In this paper, a queuing based analytical model is developed as a function of relevant determinants and functional factors to predict the travel time on pedestrian facilities. The model can be used to assess the overall serving rate or performance of a facility layout and correlate it to the level of service that is possible to provide the pedestrians. It has also the ability to provide a clear suggestion on the designing and sizing of pedestrian facilities. The model is empirically validated and is found to be a robust tool to understand how well a particular walking facility makes possible comfort and convenient pedestrian movements. The sensitivity analysis is also performed to see the impact of some crucial parameters of the developed model on the performance of pedestrian facilities. PMID:23691055

14 CFR 139.329 - Pedestrians and ground vehicles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Pedestrians and ground vehicles. 139.329... OF AIRPORTS Operations § 139.329 Pedestrians and ground vehicles. In a manner authorized by the... pedestrians and ground vehicles necessary for airport operations; (b) Establish and implement procedures for...

14 CFR 139.329 - Pedestrians and ground vehicles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Pedestrians and ground vehicles. 139.329... OF AIRPORTS Operations § 139.329 Pedestrians and ground vehicles. In a manner authorized by the... pedestrians and ground vehicles necessary for airport operations; (b) Establish and implement procedures for...

Fulfilling the pedestrian protection directive using a long-wavelength infrared camera designed to meet both performance and cost targets

NASA Astrophysics Data System (ADS)

Källhammer, Jan-Erik; Pettersson, Håkan; Eriksson, Dick; Junique, Stéphane; Savage, Susan; Vieider, Christian; Andersson, Jan Y.; Franks, John; Van Nylen, Jan; Vercammen, Hans; Kvisterøy, Terje; Niklaus, Frank; Stemme, Göran

2006-04-01

Pedestrian fatalities are around 15% of the traffic fatalities in Europe. A proposed EU regulation requires the automotive industry to develop technologies that will substantially decrease the risk for Vulnerable Road Users when hit by a vehicle. Automatic Brake Assist systems, activated by a suitable sensor, will reduce the speed of the vehicle before the impact, independent of any driver interaction. Long Wavelength Infrared technology is an ideal candidate for such sensors, but requires a significant cost reduction. The target necessary for automotive serial applications are well below the cost of systems available today. Uncooled bolometer arrays are the most mature technology for Long Wave Infrared with low-cost potential. Analyses show that sensor size and production yield along with vacuum packaging and the optical components are the main cost drivers. A project has been started to design a new Long Wave Infrared system with a ten times cost reduction potential, optimized for the pedestrian protection requirement. It will take advantage of the progress in Micro Electro-Mechanical Systems and Long Wave Infrared optics to keep the cost down. Deployable and pre-impact braking systems can become effective alternatives to passive impact protection systems solutions fulfilling the EU pedestrian protection regulation. Low-cost Long Wave Infrared sensors will be an important enabler to make such systems cost competitive, allowing high market penetration.

Safety effects of exclusive and concurrent signal phasing for pedestrian crossing.

PubMed

Zhang, Yaohua; Mamun, Sha A; Ivan, John N; Ravishanker, Nalini; Haque, Khademul

2015-10-01

This paper describes the estimation of pedestrian crash count and vehicle interaction severity prediction models for a sample of signalized intersections in Connecticut with either concurrent or exclusive pedestrian phasing. With concurrent phasing, pedestrians cross at the same time as motor vehicle traffic in the same direction receives a green phase, while with exclusive phasing, pedestrians cross during their own phase when all motor vehicle traffic on all approaches is stopped. Pedestrians crossing at each intersection were observed and classified according to the severity of interactions with motor vehicles. Observation intersections were selected to represent both types of signal phasing while controlling for other physical characteristics. In the nonlinear mixed models for interaction severity, pedestrians crossing on the walk signal at an exclusive signal experienced lower interaction severity compared to those crossing on the green light with concurrent phasing; however, pedestrians crossing on a green light where an exclusive phase was available experienced higher interaction severity. Intersections with concurrent phasing have fewer total pedestrian crashes than those with exclusive phasing but more crashes at higher severity levels. It is recommended that exclusive pedestrian phasing only be used at locations where pedestrians are more likely to comply. Copyright © 2015. Published by Elsevier Ltd.

A review of pelvic fractures in adult pedestrians: experimental studies involving PMHS used to determine injury criteria for pedestrian dummies and component test procedures.

PubMed

Arregui-Dalmases, Carlos; Kerrigan, Jason R; Sanchez-Molina, David; Velazquez-Ameijide, Juan; Crandall, Jeff R

2015-01-01

Perform a systematic review for the most relevant pelvic injury research involving PMHS. The review begins with an explanation of the pelvic anatomy and a general description of pelvic fracture patterns followed by the particular case of pelvic fractures sustained in pedestrian-vehicle collisions. Field data documenting the vehicle, crash, and human risk factors for pedestrian pelvic injuries are assessed. A summary of full-scale PMHS tests and subsystem lateral pelvic tests is provided with an interpretation of the most significant findings for the most relevant studies. Based on the mechanisms of pedestrian pelvic injury, force, acceleration, and velocity and compression have been assessed as predictive variables by researchers although no consensus criterion exists.

Effect of speed matching on fundamental diagram of pedestrian flow

NASA Astrophysics Data System (ADS)

Fu, Zhijian; Luo, Lin; Yang, Yue; Zhuang, Yifan; Zhang, Peitong; Yang, Lizhong; Yang, Hongtai; Ma, Jian; Zhu, Kongjin; Li, Yanlai

2016-09-01

Properties of pedestrian may change along their moving path, for example, as a result of fatigue or injury, which has never been properly investigated in the past research. The paper attempts to study the speed matching effect (a pedestrian adjusts his velocity constantly to the average velocity of his neighbors) and its influence on the density-velocity relationship (a pedestrian adjust his velocity to the surrounding density), known as the fundamental diagram of the pedestrian flow. By the means of the cellular automaton, the simulation results fit well with the empirical data, indicating the great advance of the discrete model for pedestrian dynamics. The results suggest that the system velocity and flow rate increase obviously under a big noise, i.e., a diverse composition of pedestrian crowd, especially in the region of middle or high density. Because of the temporary effect, the speed matching has little influence on the fundamental diagram. Along the entire density, the relationship between the step length and the average pedestrian velocity is a piecewise function combined two linear functions. The number of conflicts reaches the maximum with the pedestrian density of 2.5 m-2, while decreases by 5.1% with the speed matching.

Analyzing the impact of median treatments on pedestrian/bicyclist safety.

DOT National Transportation Integrated Search

2017-05-01

To improve pedestrian/bicyclist safety, the Maryland Department of Transportation State Highway Administration (MDOT SHA) has identified several high-frequency pedestrian/bicyclist crash locations through the Pedestrian Roadway Safety Audit (PRSA) Pr...

Screen Channel Liquid Acquisition Devices for Cryogenic Propellants

NASA Technical Reports Server (NTRS)

Chato, David J.; Kudlac, Maureen T.

2005-01-01

This paper describes an on-going project to study the application screen channel liquid acquisition devices to cryogenic propellant systems. The literature of screen liquid acquisition devices is reviewed for prior cryogenic experience. Test programs and apparatus are presented to study these devices. Preliminary results are shown demonstrating bubble points for 200 x 1400 wires per inch and 325 x 2300 wires per inch Dutch twill screens. The 200 x 1400 screen has a bubble point of 15.8 inches of water in isopropyl alcohol and 6.6 inches of water in liquid nitrogen. The 325 x 2300 screen has a bubble point of 24.5 inches of water in isopropyl alcohol, 10.7 inches of water in liquid nitrogen, and 1.83 inches of water in liquid hydrogen. These values are found to be in good agreement with the results reported in the literature.

Night-time pedestrian conspicuity: effects of clothing on drivers' eye movements.

PubMed

Wood, Joanne M; Tyrrell, Richard A; Lacherez, Philippe; Black, Alex A

2017-03-01

Drivers' responses and eye movements were assessed as they approached pedestrians at night in order to explore the relative conspicuity benefits of different configurations of retroreflective markings. Eye movements were recorded using an ASL Mobile Eye (Applied Science Technologies, www.asleyetracking.com) from 14 young licensed drivers (M = 24.1 ± 6.4 years) as they drove along a closed-road circuit at night. At two locations, pedestrians walked in place facing either towards or away from the road. Pedestrians wore black clothing with a standard retroreflective vest either alone or with additional retroreflective markers positioned in a configuration conveying biological motion (biomotion). Drivers responded when they recognised that a pedestrian was present and again when they identified the direction the pedestrian was facing. Drivers recognised pedestrians from a significantly greater distance (p < 0.05) when the pedestrian's clothing included the biomotion configuration (319.1 m) than when the biomotion markings were absent (184.5 m). Further, the drivers recognised the direction that the pedestrian faced from a longer distance when biomotion markings were present (215.4 m vs 95.6 m). Eye movement data suggested that the biomotion configuration attracted drivers' attention significantly sooner than the vest (time to first fixation: 1.1 vs 3.5 s), that drivers fixated on pedestrians wearing biomotion for significantly less time prior to responding (3.4 s vs 6.1 s), and the time to first recognise a pedestrian was approximately half that for biomotion compared to vest (6.4 vs 13.9 s). Adding biomotion reflectors to the vest facilitated earlier recognition of pedestrians and faster identification of the direction that the pedestrian faced. These findings confirm that the conspicuity advantages of biomotion configurations on pedestrians at night result in part from drivers fixating pedestrians earlier and more efficiently. © 2017 The Authors

Analysis of car-to-bicycle approach patterns for developing active safety devices.

PubMed

Matsui, Yasuhiro; Oikawa, Shoko; Hitosugi, Masahito

2016-05-18

To reduce the severity of injuries and the number of cyclist deaths in traffic accidents, active safety devices providing cyclist detection are considered to be effective countermeasures. The features of car-to-bicycle collisions need to be known in detail to develop such safety devices. The study investigated near-miss situations captured by drive recorders installed in passenger cars. Because similarities in the approach patterns between near-miss incidents and real-world fatal cyclist accidents in Japan were confirmed, we analyzed the 229 near-miss incident data via video capturing bicycles crossing the road in front of forward-moving cars. Using a video frame captured by a drive recorder, the time to collision (TTC) was calculated from the car's velocity and the distance between the car and bicycle at the moment when the bicycle initially appeared. The average TTC in the cases where bicycles emerged from behind obstructions was shorter than that in the cases where drivers had unobstructed views of the bicycles. In comparing the TTC of car-to-bicycle near-miss incidents to the previously obtained results of car-to-pedestrian near-miss incidents, it was determined that the average TTC in car-to-bicycle near-miss incidents was significantly longer than that in car-to-pedestrian near-miss incidents. When considering the TTC in the test protocol of evaluation for safety performance of active safety devices, we propose individual TTCs for evaluation of cyclist and pedestrian detections, respectively. In the test protocols, the following 2 scenarios should be employed: bicycle emerging from behind an unobstructed view and bicycle emerging from behind obstructions.

Measuring pedestrian volumes and conflicts. Volume 2, Accident prediction model

DOT National Transportation Integrated Search

1987-12-01

This final report presents the findings, conclusions, and recommendations of the study conducted to model pedestrian/vehicle accidents. A group-type analysis approach for the prediction of pedestrian/vehicle accidents using pedestrian/vehicle conflic...

Carbon nanotube circuit integration up to sub-20 nm channel lengths.

PubMed

Shulaker, Max Marcel; Van Rethy, Jelle; Wu, Tony F; Liyanage, Luckshitha Suriyasena; Wei, Hai; Li, Zuanyi; Pop, Eric; Gielen, Georges; Wong, H-S Philip; Mitra, Subhasish

2014-04-22

Carbon nanotube (CNT) field-effect transistors (CNFETs) are a promising emerging technology projected to achieve over an order of magnitude improvement in energy-delay product, a metric of performance and energy efficiency, compared to silicon-based circuits. However, due to substantial imperfections inherent with CNTs, the promise of CNFETs has yet to be fully realized. Techniques to overcome these imperfections have yielded promising results, but thus far only at large technology nodes (1 μm device size). Here we demonstrate the first very large scale integration (VLSI)-compatible approach to realizing CNFET digital circuits at highly scaled technology nodes, with devices ranging from 90 nm to sub-20 nm channel lengths. We demonstrate inverters functioning at 1 MHz and a fully integrated CNFET infrared light sensor and interface circuit at 32 nm channel length. This demonstrates the feasibility of realizing more complex CNFET circuits at highly scaled technology nodes.

Modeling pedestrian gap crossing index under mixed traffic condition.

PubMed

Naser, Mohamed M; Zulkiple, Adnan; Al Bargi, Walid A; Khalifa, Nasradeen A; Daniel, Basil David

2017-12-01

There are a variety of challenges faced by pedestrians when they walk along and attempt to cross a road, as the most recorded accidents occur during this time. Pedestrians of all types, including both sexes with numerous aging groups, are always subjected to risk and are characterized as the most exposed road users. The increased demand for better traffic management strategies to reduce the risks at intersections, improve quality traffic management, traffic volume, and longer cycle time has further increased concerns over the past decade. This paper aims to develop a sustainable pedestrian gap crossing index model based on traffic flow density. It focusses on the gaps accepted by pedestrians and their decision for street crossing, where (Log-Gap) logarithm of accepted gaps was used to optimize the result of a model for gap crossing behavior. Through a review of extant literature, 15 influential variables were extracted for further empirical analysis. Subsequently, data from the observation at an uncontrolled mid-block in Jalan Ampang in Kuala Lumpur, Malaysia was gathered and Multiple Linear Regression (MLR) and Binary Logit Model (BLM) techniques were employed to analyze the results. From the results, different pedestrian behavioral characteristics were considered for a minimum gap size model, out of which only a few (four) variables could explain the pedestrian road crossing behavior while the remaining variables have an insignificant effect. Among the different variables, age, rolling gap, vehicle type, and crossing were the most influential variables. The study concludes that pedestrians' decision to cross the street depends on the pedestrian age, rolling gap, vehicle type, and size of traffic gap before crossing. The inferences from these models will be useful to increase pedestrian safety and performance evaluation of uncontrolled midblock road crossings in developing countries. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Robust Pedestrian Classification Based on Hierarchical Kernel Sparse Representation

PubMed Central

Sun, Rui; Zhang, Guanghai; Yan, Xiaoxing; Gao, Jun

2016-01-01

Vision-based pedestrian detection has become an active topic in computer vision and autonomous vehicles. It aims at detecting pedestrians appearing ahead of the vehicle using a camera so that autonomous vehicles can assess the danger and take action. Due to varied illumination and appearance, complex background and occlusion pedestrian detection in outdoor environments is a difficult problem. In this paper, we propose a novel hierarchical feature extraction and weighted kernel sparse representation model for pedestrian classification. Initially, hierarchical feature extraction based on a CENTRIST descriptor is used to capture discriminative structures. A max pooling operation is used to enhance the invariance of varying appearance. Then, a kernel sparse representation model is proposed to fully exploit the discrimination information embedded in the hierarchical local features, and a Gaussian weight function as the measure to effectively handle the occlusion in pedestrian images. Extensive experiments are conducted on benchmark databases, including INRIA, Daimler, an artificially generated dataset and a real occluded dataset, demonstrating the more robust performance of the proposed method compared to state-of-the-art pedestrian classification methods. PMID:27537888

Robust Pedestrian Classification Based on Hierarchical Kernel Sparse Representation.

PubMed

Sun, Rui; Zhang, Guanghai; Yan, Xiaoxing; Gao, Jun

2016-08-16

Vision-based pedestrian detection has become an active topic in computer vision and autonomous vehicles. It aims at detecting pedestrians appearing ahead of the vehicle using a camera so that autonomous vehicles can assess the danger and take action. Due to varied illumination and appearance, complex background and occlusion pedestrian detection in outdoor environments is a difficult problem. In this paper, we propose a novel hierarchical feature extraction and weighted kernel sparse representation model for pedestrian classification. Initially, hierarchical feature extraction based on a CENTRIST descriptor is used to capture discriminative structures. A max pooling operation is used to enhance the invariance of varying appearance. Then, a kernel sparse representation model is proposed to fully exploit the discrimination information embedded in the hierarchical local features, and a Gaussian weight function as the measure to effectively handle the occlusion in pedestrian images. Extensive experiments are conducted on benchmark databases, including INRIA, Daimler, an artificially generated dataset and a real occluded dataset, demonstrating the more robust performance of the proposed method compared to state-of-the-art pedestrian classification methods.

A comparison of alcohol involvement in pedestrians and pedestrian casualties

DOT National Transportation Integrated Search

1979-10-01

The objectives of this study were to determine the frequency of alcohol involvement in adult (14 years +) pedestrian fatalities and injuries; determine if alcohol was overrepresented; determine the causal role of alcohol; and suggest countermeasures....

Understanding interactions between drivers and pedestrian features at signalized intersections.

DOT National Transportation Integrated Search

2015-10-01

Florida experienced serious pedestrian safety problems and had the highest pedestrian fatality rate in the U.S. from : 20082011. Pedestrian safety at signalized intersections is the most serious concern due to frequent and severe : conflicts betwe...

Establishing procedures and guidelines for pedestrian treatments at uncontrolled locations

DOT National Transportation Integrated Search

2017-08-01

Pedestrians are the most vulnerable road users. The risks to pedestrians crossing at uncontrolled locations are much higher than at signalized intersections. There has been an increasing trend in pedestrian deaths during the past decade. Specifically...

Traffic signal phasing at intersections to improve safety for alcohol-affected pedestrians.

PubMed

Lenné, Michael G; Corben, Bruce F; Stephan, Karen

2007-07-01

Alcohol-affected pedestrians are among the highest-risk groups involved in pedestrian casualty crashes. This paper investigates the opportunities to use a modified form of traffic signal operation during high-risk periods and at high-risk locations to reduce alcohol-affected pedestrian crashes and the severity of injuries that might otherwise occur. The 'Dwell-on-Red' treatment involves displaying a red traffic signal to all vehicle directions during periods when no vehicular traffic is detected, so that drivers approach high-risk intersections at a lower speed than if a green signal were displayed. Vehicle speed data were collected before and after treatment activation at both a control and treatment site. Speed data were collected both 30 m prior to and at the intersection stop line. The treatment was associated with a reduction in mean vehicle speeds of 3.9 kph (9%) and 11.0 kph (28%) at 30 m and stop line collection points, respectively, and substantial reductions in the proportion of vehicles travelling at threatening speeds with regard to the severity of pedestrian injury. Other important road safety concerns may also benefit from this form of traffic signal modification, and it is recommended that other areas of application be explored, including the other severe trauma categories typically concentrated around signalised intersections.

A Finite Element Model of a Midsize Male for Simulating Pedestrian Accidents.

PubMed

Untaroiu, Costin D; Pak, Wansoo; Meng, Yunzhu; Schap, Jeremy; Koya, Bharath; Gayzik, Scott

2018-01-01

Pedestrians represent one of the most vulnerable road users and comprise nearly 22% the road crash-related fatalities in the world. Therefore, protection of pedestrians in car-to-pedestrian collisions (CPC) has recently generated increased attention with regulations involving three subsystem tests. The development of a finite element (FE) pedestrian model could provide a complementary component that characterizes the whole-body response of vehicle-pedestrian interactions and assesses the pedestrian injuries. The main goal of this study was to develop and to validate a simplified full body FE model corresponding to a 50th male pedestrian in standing posture (M50-PS). The FE model mesh and defined material properties are based on a 50th percentile male occupant model. The lower limb-pelvis and lumbar spine regions of the human model were validated against the postmortem human surrogate (PMHS) test data recorded in four-point lateral knee bending tests, pelvic\\abdomen\\shoulder\\thoracic impact tests, and lumbar spine bending tests. Then, a pedestrian-to-vehicle impact simulation was performed using the whole pedestrian model, and the results were compared to corresponding PMHS tests. Overall, the simulation results showed that lower leg response is mostly within the boundaries of PMHS corridors. In addition, the model shows the capability to predict the most common lower extremity injuries observed in pedestrian accidents. Generally, the validated pedestrian model may be used by safety researchers in the design of front ends of new vehicles in order to increase pedestrian protection.

A Field Data Analysis of Risk Factors Affecting the Injury Risks in Vehicle-To-Pedestrian Crashes

PubMed Central

Zhang, Guanjun; Cao, Libo; Hu, Jingwen; Yang, King H.

2008-01-01

The head, torso, and lower extremity are the most commonly injured body regions during vehicle-to-pedestrian crashes. A total of 312 cases were selected from the National Automotive Sampling System (NASS) Pedestrian Crash Data Study (PCDS) database to investigate factors affecting the likelihood of sustaining MAIS 3+, AIS 3+ head, AIS 3+ torso, and AIS 2+ lower extremity injuries during vehicle-to-pedestrian frontal crashes. The inclusion criteria were pedestrians: (a) aged 14 years or older, (b) with a height of 1.5 m and taller, and (c) who were injured in an upright standing position via vehicle frontal collision. The injury odds ratios (ORs) calculated from logistic regression analyses were used to evaluate the association between selected injury predictors and the odds of sustaining pedestrian head, torso, and lower extremity injuries. These predictors included a crash factor (impact speed), pedestrian factors (age, gender, height, and weight), and vehicle factors (front bumper central height, front bumper lead, ground to front/top transition point height (FTTPH), and rear hood opening distance (RHOD)). Results showed that impact speed was a statistically significant predictor for head, torso, and lower extremity injury odds, as expected. Comparison of people 65 years of age and older to young adults aged 14 to 64 showed that age was also a significant predictor for torso (p<0.001, OR=23.8) and lower extremity (p=0.020, OR=2.44) injury odds, but not for head injuries (p=0.661). Vehicles with higher FTTPH and more vertical frontal structures were aggressive to pedestrians, especially regarding injuries to the torso. A very short RHOD would be more likely to lead the pedestrian to impact the windshield and windshield frame, thus increasing the head injury risk. PMID:19026237

Analyzing fault and severity in pedestrian-motor vehicle accidents in China.

PubMed

Zhang, Guangnan; Yau, Kelvin K W; Zhang, Xun

2014-12-01

The number of pedestrian-motor vehicle accidents and pedestrian deaths in China surged in recent years. However, a large scale empirical research on pedestrian traffic crashes in China is lacking. In this study, we identify significant risk factors associated with fault and severity in pedestrian-motor vehicle accidents. Risk factors in several different dimensions, including pedestrian, driver, vehicle, road and environmental factors, are considered. We analyze 6967 pedestrian traffic accident reports for the period 2006-2010 in Guangdong Province, China. These data, obtained from the Guangdong Provincial Security Department, are extracted from the Traffic Management Sector-Specific Incident Case Data Report. Pedestrian traffic crashes have a unique inevitability and particular high risk, due to pedestrians' fragility, slow movement and lack of lighting equipment. The empirical analysis of the present study has the following policy implications. First, traffic crashes in which pedestrians are at fault are more likely to cause serious injuries or death, suggesting that relevant agencies should pay attention to measures that prevent pedestrians from violating traffic rules. Second, both the attention to elderly pedestrians, male and experienced drivers, the penalty to drunk driving, speeding, driving without a driver's license and other violation behaviors should be strengthened. Third, vehicle safety inspections and safety training sessions for truck drivers should be reinforced. Fourth, improving the road conditions and road lighting at night are important measures in reducing the probability of accident casualties. Fifth, specific road safety campaigns in rural areas, and education programs especially for young children and teens should be developed and promoted. Moreover, we reveal a country-specific factor, hukou, which has significant effect on the severity in pedestrian accidents due to the discrepancy in the level of social insurance/security, suggesting

Fatigue effect on phase transition of pedestrian movement: experiment and simulation study

NASA Astrophysics Data System (ADS)

Luo, Lin; Fu, Zhijian; Zhou, Xiaodong; Zhu, Kongjin; Yang, Hongtai; Yang, Lizhong

2016-10-01

How to model pedestrian movement is an intriguing problem in the area of statistical physics. As a common phenomenon of pedestrian movement, fatigue has a significant negative effect on pedestrian movement, especially when pedestrians move or run with heavy luggage, rescue the wounded in disaster, climb stairs and etc. According to the field observations and previous researches, fatigue coefficient is defined as the decrease of desired velocity in this study. However, previous researches lacked quantitative analysis of the effect of fatigue on pedestrian speed. It has been a great challenge to study the effect of fatigue on pedestrian flow, since pedestrians of heterogeneous walking abilities and the change of pedestrians’ moving properties need to be taken into consideration. Thus, at first, a series of pedestrian experiments, under three different conditions, were conducted to formulate the empirical relationship among fatigue, average free velocity, and walking distance. Then the empirical formulation of pedestrian fatigue was imported into the multi-velocity field floor cellular automata (FFCA) model for following pedestrian dynamics analysis. The velocity ratio was adjusted dynamically to adapt the change of pedestrians’ velocity due to fatigue. The fatigue, entrance flow rate and pedestrian’s initial desired velocity are found to have significant effects on the pedestrian flow. The space-time distributions of pedestrian density and velocity were explored in detail, with phase transition analyses from a free flow phase to a congestion phase. Additionally, the ‘density wave’ in the system can be observed if a certain ratio of burdened pedestrians lay in the high density region. The envelope of the ‘density wave’ reaches its maximum amplitude around the entrance position, and gradually diminishes away from the entrance.

Brake reactions of distracted drivers to pedestrian Forward Collision Warning systems.

PubMed

Lubbe, Nils

2017-06-01

Forward Collision Warning (FCW) can be effective in directing driver attention towards a conflict and thereby aid in preventing or mitigating collisions. FCW systems aiming at pedestrian protection have been introduced onto the market, yet an assessment of their safety benefits depends on the accurate modeling of driver reactions when the system is activated. This study contributes by quantifying brake reaction time and brake behavior (deceleration levels and jerk) to compare the effectiveness of an audio-visual warning only, an added haptic brake pulse warning, and an added Head-Up Display in reducing the frequency of collisions with pedestrians. Further, this study provides a detailed data set suited for the design of assessment methods for car-to-pedestrian FCW systems. Brake response characteristics were measured for heavily distracted drivers who were subjected to a single FCW event in a high-fidelity driving simulator. The drivers maintained a self-regulated speed of 30km/h in an urban area, with gaze direction diverted from the forward roadway by a secondary task. Collision rates and brake reaction times differed significantly across FCW settings. Brake pulse warnings resulted in the lowest number of collisions and the shortest brake reaction times (mean 0.8s, SD 0.29s). Brake jerk and deceleration were independent of warning type. Ninety percent of drivers exceeded a maximum deceleration of 3.6m/s 2 and a jerk of 5.3m/s 3 . Brake pulse warning was the most effective FCW interface for preventing collisions. In addition, this study presents the data required for driver modeling for car-to-pedestrian FCW similar to Euro NCAP's 2015 car-to-car FCW assessment. Practical applications: Vehicle manufacturers should consider the introduction of brake pulse warnings to their FCW systems. Euro NCAP could introduce an assessment that quantifies the safety benefits of pedestrian FCW systems and thereby aid the proliferation of effective systems. Copyright © 2017

In pedestrian crashes, it's vehicle speed that matters the most

DOT National Transportation Integrated Search

2000-05-13

A recently prepared report on pedestrian injuries provides these two main findings: 1) regardless of age, pedestrians involved in crashes are more likely to be killed as vehicle speeds increase; and 2) in crashes at any speed, older pedestrians are m...

Examining the Characteristics of Fatal Pedestrian Crashes

DOT National Transportation Integrated Search

2016-11-01

Pedestrian safety has become a strategic priority for UDOT over the past two years. In Utah, pedestrians make up over 12% of total roadway fatalities while less than 2% of all trips are taken on foot. This over-representation of risk led to the creat...

Screen channel liquid acquisition device outflow tests in liquid hydrogen

NASA Astrophysics Data System (ADS)

Hartwig, J. W.; Chato, D. J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

2014-11-01

This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325 × 2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3-24.2 K), pressures (100-350 kPa), and flow rates (0.010-0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

Screen Channel Liquid Acquisition Device Outflow Tests in Liquid Hydrogen

NASA Technical Reports Server (NTRS)

Hartwig, Jason W.; Chato, David J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

2013-01-01

This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325x2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3 - 24.2 K), pressures (100 - 350 kPa), and flow rates (0.010 - 0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

Performance of collision damage mitigation braking systems and their effects on human injury in the event of car-to-pedestrian accidents.

PubMed

Matsui, Yasuhiro; Han, Yong; Mizuno, Koji

2011-11-01

The number of traffic deaths in Japan was 4,863 in 2010. Pedestrians account for the highest number (1,714, 35%), and vehicle occupants the second highest (1,602, 33%). Pedestrian protection is a key countermeasure to reduce casualties in traffic accidents. A striking vehicle's impact velocity could be considered a parameter influencing the severity of injury and possibility of death in pedestrian crashes. A collision damage mitigation braking system (CDMBS) using a sensor to detect pedestrians could be effective for reducing the vehicle/pedestrian impact velocity. Currently in Japan, cars equipped with the CDMBS also have vision sensors such as a stereo camera for pedestrian detection. However, the ability of vision sensors in production cars to properly detect pedestrians has not yet been established. The effect of reducing impact velocity on the pedestrian injury risk has also not been determined. The first objective of this study is to evaluate the performance of the CDMBS in detecting pedestrians when it is installed in production cars. The second objective of this study is to evaluate the effect of reducing impact velocity on mitigating pedestrian injury. Firstly, impact experiments were performed using a car with the CDMBS in which the car collided with a pedestrian surrogate. In these tests, the velocity was chosen for the various test runs to be 20, 40 and 60 km/h, respectively, which were based on the velocity distribution in real-world pedestrian crashes. The results indicated that the impact velocity reduction ranged approximately from 10 to 15 km/h at the standing location of a pedestrian surrogate at both daytime and nighttime lighting conditions. These results show that the system has the potential to reduce pedestrian casualties from car-to-pedestrian contacts. Secondly, finite-element analyses were performed simulating vehicle-to- pedestrian impacts with the THUMS pedestrian models. The vehicle models selected for the study included a medium sedan

Modeling pedestrian evacuation by means of game theory

NASA Astrophysics Data System (ADS)

Shi, Dongmei; Zhang, Wenyao; Wang, Binghong

2017-04-01

Pedestrian evacuation is studied based on a modified lattice model. The payoff matrix in this model represents the complicated interactions between selfish individuals, and the mean force imposed on an individual is given by considering the impacts of neighbors, walls, and defector herding. Each passer-by moves to his selected location according to the Fermi function, and the average velocity of pedestrian flow is defined as a function of the motion rule. Two pedestrian types are included: cooperators, who adhere to the evacuation instructions; and defectors, who ignore the rules and act individually. It is observed that the escape time increases as fear degree increases, and the system remains smooth for a low fear degree, but exhibits three stages for a high fear degree. We prove that the fear degree determines the dynamics of this system, and the initial density of cooperators has a negligible impact. The system experiences three phases, a single phase of cooperator, a mixed two-phase pedestrian, and a single phase of defector sequentially as the fear degree upgrades. The phase transition has been proven basically robust to the changes of empty site contribution, wall’s pressure, and noise amplitude in the motion rule. It is further shown that pedestrians derive the greatest benefit from overall cooperation, but are trapped in the worst situation if they are all defectors. Dynamics of pedestrian evacuation.

Paediatric pedestrian trauma: the danger after school.

PubMed

Newbury, Clinton; Hsiao, Kai; Dansey, Rangi; Hamill, James

2008-09-01

To examine the demographics of road pedestrian trauma in children in the Auckland region and to provide data that can help target prevention strategies. A retrospective analysis was conducted of all children (0-14 years) in the Auckland region admitted to the hospital or killed following a pedestrian versus vehicle injury for the 6-year period 2000-2005. Excluded were pedestrians injured in a driveway. Over the 6-year period, 364 children were involved in pedestrian crashes resulting in 25 deaths. The median age was 7 years. Males comprised 63%. Pacific Islanders and Maori were over-represented. Three hundred seventeen patients had injury times recorded. Of these, 49% occurred between 3 and 7 pm. Injury peaks for school days showed a tri-modal pattern with injury peaks at 8-9 am, 3-4 pm and 5-6 pm with the 3-4 pm after-school peak predominating. Prevention strategies should concentrate on the hours after school finishes and should be tailored for Maori and Pacific Island communities.

Modeling pedestrian violation behavior at signalized crosswalks in China: a hazards-based duration approach.

PubMed

Guo, Hongwei; Gao, Ziyou; Yang, Xiaobao; Jiang, Xiaobei

2011-02-01

Pedestrian violation is a major cause of traffic accidents involving pedestrians. The research objectives were to investigate the relationship between waiting duration and pedestrian violation and to provide a qualitative and quantitative analysis of the effects of human factors and external environmental factors on street-crossing behavior. Pedestrians' street-crossing behavior was examined by modeling the waiting duration at signalized crosswalk. Pedestrian waiting duration was collected by video cameras and it was assigned as censored and uncensored data to distinguish between normal crossing and violating crossing. A nonparametric baseline duration model was introduced, and variables revealing personal characteristics, traffic conditions, and trip features were defined as covariates to describe the effects of internal and external factors. Pedestrians' crossing behaviors represented positive duration dependence that the longer the waiting time elapsed the more likely pedestrians would end the wait soon. The violation inclination of most pedestrians increased with the increasing waiting duration, but about 10 percent of pedestrians were at high risk of violation to cross the street. About half of pedestrians would still obey the traffic rules even after waiting for 50 s by the street. Human factors and the external environment played an important role in street-crossing behavior, especially for factors that involved pedestrians' subjective willingness. The street-crossing behavior of pedestrians was time dependent. Pedestrians behave differently under the effects of various factors. Pedestrian safety interventions that aim at reducing pedestrian injuries may need to consider these effects. The pedestrians' behavioral modifications, such as enhancing the safety awareness, might be the most efficient means to reducing the likelihood of pedestrian violation, though environmental modifications also worked well in improving pedestrian safety.

Update schemes of multi-velocity floor field cellular automaton for pedestrian dynamics

NASA Astrophysics Data System (ADS)

Luo, Lin; Fu, Zhijian; Cheng, Han; Yang, Lizhong

2018-02-01

Modeling pedestrian movement is an interesting problem both in statistical physics and in computational physics. Update schemes of cellular automaton (CA) models for pedestrian dynamics govern the schedule of pedestrian movement. Usually, different update schemes make the models behave in different ways, which should be carefully recalibrated. Thus, in this paper, we investigated the influence of four different update schemes, namely parallel/synchronous scheme, random scheme, order-sequential scheme and shuffled scheme, on pedestrian dynamics. The multi-velocity floor field cellular automaton (FFCA) considering the changes of pedestrians' moving properties along walking paths and heterogeneity of pedestrians' walking abilities was used. As for parallel scheme only, the collisions detection and resolution should be considered, resulting in a great difference from any other update schemes. For pedestrian evacuation, the evacuation time is enlarged, and the difference in pedestrians' walking abilities is better reflected, under parallel scheme. In face of a bottleneck, for example a exit, using a parallel scheme leads to a longer congestion period and a more dispersive density distribution. The exit flow and the space-time distribution of density and velocity have significant discrepancies under four different update schemes when we simulate pedestrian flow with high desired velocity. Update schemes may have no influence on pedestrians in simulation to create tendency to follow others, but sequential and shuffled update scheme may enhance the effect of pedestrians' familiarity with environments.

Community-based pedestrian safety training in virtual reality: A pragmatic trial.

PubMed

Schwebel, David C; Combs, Tabitha; Rodriguez, Daniel; Severson, Joan; Sisiopiku, Virginia

2016-01-01

Child pedestrian injuries are a leading cause of mortality and morbidity across the United States and the world. Repeated practice at the cognitive-perceptual task of crossing a street may lead to safer pedestrian behavior. Virtual reality offers a unique opportunity for repeated practice without the risk of actual injury. This study conducted a pre-post within-subjects trial of training children in pedestrian safety using a semi-mobile, semi-immersive virtual pedestrian environment placed at schools and community centers. Pedestrian safety skills among a group of 44 seven- and eight-year-old children were assessed in a laboratory, and then children completed six 15-minute training sessions in the virtual pedestrian environment at their school or community center following pragmatic trial strategies over the course of three weeks. Following training, pedestrian safety skills were re-assessed. Results indicate improvement in delay entering traffic following training. Safe crossings did not demonstrate change. Attention to traffic and time to contact with oncoming vehicles both decreased somewhat, perhaps an indication that training was incomplete and children were in the process of actively learning to be safer pedestrians. The findings suggest virtual reality environments placed in community centers hold promise for teaching children to be safer pedestrians, but future research is needed to determine the optimal training dosage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of demographic analysis to pedestrian safety : [project summary].

DOT National Transportation Integrated Search

2017-05-01

FDOT has been working diligently to improve its facilities for pedestrians and cyclists, including : initiatives like the Complete Streets Policy and Implementation Plan. However, one of the : challenges facing FDOT is targeting those areas of greate...

The relationship between the availability of the supporting elements of pedestrian with pedestrian crossing facility usage based on user preferences (Case Study corridor of Sumbersari Street, Gajayana Street, MT. Haryono Street, Malang City)

NASA Astrophysics Data System (ADS)

Soetrisno, D. P.

2017-06-01

Pedestrian crossing facilities are effective enough to avoid pedestrians with vehicles, but its utilization is still quite low. It indicated that safety is not the only factor that influences a person to utilize the pedestrian crossing facilities. In addition, the availability of supporting elements of the pedestrian is still not quite attention, which is also became a factor that causes the pedestrians doesn’t utilize the pedestrian crossing facilities. Therefore, this research was structured to examine the relationship between the availability of the supporting elements of the pedestrian with pedestrian crossing facility usage based on user preferences. Data collection method used is primary survey consist of observation and the questionnaire. Sampling techniques used is purposive sampling with the number of respondents as many as 211 respondents by using questionnaire with ordinal scales to identify respondents’ consideration level of supporting elements pedestrian and crossing facility utilization factors. The survey is done on 15 crossing facilities area in 3 different locations with the same characteristics of land use in the form of higher education area (university area) and trades and services activities area. The analysis technique used is frequency distribution analysis in order to identify preference pedestrian on the availability of supporting elements of pedestrian and pedestrian crossing facility utilization factors, and chi square analysis is used to analyze the relationship between the availability of the supporting elements of the pedestrian with pedestrian crossing facility utilization. Based on the chi square analysis results with significance 5 % obtained the result that there are six supporting elements of pedestrian having correlation to the factors of pedestrian crossing facility utilization consist of the availability of sidewalk, pedestrian lights, Street Lighting Lamps, Pedestrian Crossing Markings Facilities, Sign Crossings

Development and test of rural pedestrian safety countermeasures

DOT National Transportation Integrated Search

1983-12-01

Prior to any promulgation by NHTSA of four model traffic regulations for rural pedestrian safety it was the objective of this study to assess, where feasible, the potential effectiveness of these regulations to prevent pedestrian accidents. The model...

Relations between temperamental fear and risky pedestrian behavior.

PubMed

Shen, Jiabin; McClure, Leslie A; Schwebel, David C

2015-07-01

Child pedestrian injury poses a significant global public health challenge. This study examines relations between temperamental fear and children's risky pedestrian behavior, utilizing mediation analytic strategies to study underlying mechanisms of the hypothesized relation. As part of a larger study, 240 seven- and eight-year-old children completed 30 crossings in a virtual reality (VR) pedestrian environment. Three pedestrian behaviors were considered: start gap (lag after a traffic gap appears before child initiates crossing into the gap), time to contact (TTC; gap between avatar and the lead oncoming vehicle), and hits (collisions with vehicles in simulated crossings). Temperamental fear was measured by parent report. Fearful children were more likely to be struck by virtual vehicles, and the relation between fear and risky pedestrian behaviors was mediated by start gap and TTC. Specifically, children who were temperamentally more fearful were more likely to hesitate before initiating crossing, which led to shorter gaps between themselves and the oncoming vehicle, hence causing them to be more likely to be hit by virtual vehicles. Gender interacted with fear, such that fearful girls were most likely to be hit. Both temperamental fear and gender influenced the risk of child pedestrian injuries. Delayed entry into traffic and shorter gaps between children and oncoming vehicles may underlie this relation. Future research should explore how these factors might influence the effectiveness of prevention programs. Copyright © 2015. Published by Elsevier Ltd.

Vehicle-to-pedestrian research at the USDOT : white paper.

DOT National Transportation Integrated Search

2017-02-01

Connecting vehicles with the surrounding infrastructure through Vehicle-to-Pedestrian (V2P) technology offers promise for addressing this challenge. For the past decade, the USDOT has been researching and testing a connected vehicle (CV) system where...

Centrifugal sedimentation for selectively packing channels with silica microbeads in three-dimensional micro/nanofluidic devices.

PubMed

Gong, Maojun; Bohn, Paul W; Sweedler, Jonathan V

2009-03-01

Incorporation of nanofluidic elements into microfluidic channels is one approach for adding filtration and partition functionality to planar microfluidic devices, as well as providing enhanced biomolecular separations. Here we introduce a strategy to pack microfluidic channels with silica nanoparticles and microbeads, thereby indirectly producing functional nanostructures; the method allows selected channels to be packed, here demonstrated so that a separation channel is packed while keeping an injection channel unpacked. A nanocapillary array membrane is integrated between two patterned microfluidic channels that cross each other in vertically separated layers. The membrane serves both as a frit for bead packing and as a fluid communication conduit between microfluidic channels. Centrifugal force-assisted sedimentation is then used to selectively pack the microfluidic channels using an aqueous silica bead suspension loaded into the appropriate inlet reservoirs. This packing approach may be used to simultaneously pack multiple channels with silica microbeads having different sizes and surface properties. The chip design and packing method introduced here are suitable for packing silica particles in sizes ranging from nanometers to micrometers and allow rapid (approximately 10 min) packing with high quality. The liquid/analyte transport characteristics of these packed micro/nanofluidic devices have potential utility in a wide range of applications, including electroosmotic pumping, liquid chromatographic separations, and electrochromatography.

The effect of high-visibility enforcement on driver compliance with pedestrian right-of-way laws : four-year follow-up.

DOT National Transportation Integrated Search

2017-01-01

This is a follow-up to a previous study titled High-Visibility Enforcement on Driver Compliance With Pedestrian Right-of-Way Laws to determine the extent observed increases in driver yielding in the previous study persisted nearly 4 years after the h...

Introduction of frictional and turning function for pedestrian outflow with an obstacle.

PubMed

Yanagisawa, Daichi; Kimura, Ayako; Tomoeda, Akiyasu; Nishi, Ryosuke; Suma, Yushi; Ohtsuka, Kazumichi; Nishinari, Katsuhiro

2009-09-01

In this paper, two important factors which affect the pedestrian outflow at a bottleneck significantly are studied in detail to analyze the effect of an obstacle setup in front of an exit. One is a conflict at an exit when pedestrians evacuate from a room. We use floor field model for simulating such behavior, which is a well-studied pedestrian model using cellular automata. The conflicts have been taken into account by the friction parameter. However, the friction parameter so far is a constant and does not depend on the number of the pedestrians conflicting at the same time. Thus, we have improved the friction parameter by the frictional function, which is a function of the number of the pedestrians involved in the conflict. Second, we have presented the cost of turning of pedestrians at the exit. Since pedestrians have inertia, their walking speeds decrease when they turn and the pedestrian outflow decreases. The validity of the extended model, which includes the frictional function and the turning function, is supported by the comparison of a mean-field theory and real experiments. We have observed that the pedestrian flow increases when we put an obstacle in front of an exit in our real experiments. The analytical results clearly explains the mechanism of the effect of the obstacle, i.e., the obstacle blocks pedestrians moving to the exit and decreases the average number of pedestrians involved in the conflict. We have also found that an obstacle works more effectively when we shift it from the center since pedestrians go through the exit with less turning.

Pedestrian friendly traffic signal control : final research report.

DOT National Transportation Integrated Search

2016-01-01

This project continues research aimed at real-time detection and use of pedestrian : traffic flow information to enhance adaptive traffic signal control in urban areas : where pedestrian traffic is substantial and must be given appropriate attention ...

Development of a portable bicycle/pedestrian monitoring system for safety enhancement

NASA Astrophysics Data System (ADS)

Usher, Colin; Daley, W. D. R.

2015-03-01

Pedestrians involved in roadway accidents account for nearly 12 percent of all traffic fatalities and 59,000 injuries each year. Most injuries occur when pedestrians attempt to cross roads, and there have been noted differences in accident rates midblock vs. at intersections. Collecting data on pedestrian behavior is a time consuming manual process that is prone to error. This leads to a lack of quality information to guide the proper design of lane markings and traffic signals to enhance pedestrian safety. Researchers at the Georgia Tech Research Institute are developing and testing an automated system that can be rapidly deployed for data collection to support the analysis of pedestrian behavior at intersections and midblock crossings with and without traffic signals. This system will analyze the collected video data to automatically identify and characterize the number of pedestrians and their behavior. It consists of a mobile trailer with four high definition pan-tilt cameras for data collection. The software is custom designed and uses state of the art commercial pedestrian detection algorithms. We will be presenting the system hardware and software design, challenges, and results from the preliminary system testing. Preliminary results indicate the ability to provide representative quantitative data on pedestrian motion data more efficiently than current techniques.

A comparison of alcohol involvement in pedestrians and pedestrian casualties

DOT National Transportation Integrated Search

1979-10-01

A field accident research study was conducted in the City of New Orleans in : 1975-76 in order to (1) determine the percentage and relative risk of alcohol involvement : in adult pedestrian fatal and injury accidents; (2) identify in the alcohol invo...

Epidemiology of pedestrian-MVCs by road type in Cluj, Romania.

PubMed

Hamann, Cara; Peek-Asa, Corinne; Rus, Diana

2015-04-01

Pedestrian-motor vehicle (PMV) crash rates in Romania are among the highest in all of Europe. The purpose of this study was to examine the characteristics of pedestrian-MVCs in Cluj County, Romania, on the two major types of roadways: national or local. Cluj County police crash report data from 2010 were used to identify pedestrian, driver and crash characteristics of pedestrian-MVCs. Crashes with available location data were geocoded and road type (national or local) for each crash was determined. Distributions of crash characteristics were examined by road type and multivariable logistic regression models were built to determine predictors of crash road type. Crashes occurring on national roads involved more teenagers and adults, while those on local roads involved more young children (0-12) and older adults (65+) (p<0.01). Crashes on national roads were more likely to have marked pedestrian crossings and shoulders compared with local crashes. Pedestrian-MVCs that involved a moving violation by the motorist were more likely to occur on national roadways (adjusted OR=1.93, 95% CI 1.07 to 3.49). Pedestrian-MVCs pose a considerable health burden in Romania. Results from this study suggest that factors leading to PMV crashes on national roads are more likely to involve driver-related causes compared with local roads. Intervention priorities to reduce pedestrian crashes on national roads should be directed towards driver behaviour on national roads. Further examination of driver and pedestrian behaviours related to crash risk on both national and local roads, such as distraction and speeding, is warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Training strategy for convolutional neural networks in pedestrian gender classification

NASA Astrophysics Data System (ADS)

Ng, Choon-Boon; Tay, Yong-Haur; Goi, Bok-Min

2017-06-01

In this work, we studied a strategy for training a convolutional neural network in pedestrian gender classification with limited amount of labeled training data. Unsupervised learning by k-means clustering on pedestrian images was used to learn the filters to initialize the first layer of the network. As a form of pre-training, supervised learning for the related task of pedestrian classification was performed. Finally, the network was fine-tuned for gender classification. We found that this strategy improved the network's generalization ability in gender classification, achieving better test results when compared to random weights initialization and slightly more beneficial than merely initializing the first layer filters by unsupervised learning. This shows that unsupervised learning followed by pre-training with pedestrian images is an effective strategy to learn useful features for pedestrian gender classification.

Environmental characteristics associated with pedestrian-motor vehicle collisions in Denver, Colorado.

PubMed

Sebert Kuhlmann, Anne K; Brett, John; Thomas, Deborah; Sain, Stephan R

2009-09-01

We examined patterns of pedestrian-motor vehicle collisions and associated environmental characteristics in Denver, Colorado. We integrated publicly available data on motor vehicle collisions, liquor licenses, land use, and sociodemographic characteristics to analyze spatial patterns and other characteristics of collisions involving pedestrians. We developed both linear and spatially weighted regression models of these collisions. Spatial analysis revealed global clustering of pedestrian-motor vehicle collisions with concentrations in downtown, in a contiguous neighborhood, and along major arterial streets. Walking to work, population density, and liquor license outlet density all contributed significantly to both linear and spatial models of collisions involving pedestrians and were each significantly associated with these collisions. These models, constructed with data from Denver, identified conditions that likely contribute to patterns of pedestrian-motor vehicle collisions. Should these models be verified elsewhere, they will have implications for future research directions, public policy to enhance pedestrian safety, and public health programs aimed at decreasing unintentional injury from pedestrian-motor vehicle collisions and promoting walking as a routine physical activity.

Spatial Analysis in Determining Physical Factors of Pedestrian Space Livability, Case Study: Pedestrian Space on Jalan Kemasan, Yogyakarta

NASA Astrophysics Data System (ADS)

Fauzi, A. F.; Aditianata, A.

2018-02-01

The existence of street as a place to perform various human activities becomes an important issue nowadays. In the last few decades, cars and motorcycles dominate streets in various cities in the world. On the other hand, human activity on the street is the determinant of the city livability. Previous research has pointed out that if there is lots of human activity in the street, then the city will be interesting. Otherwise, if the street has no activity, then the city will be boring. Learning from that statement, now various cities in the world are developing the concept of livable streets. Livable streets shown by diversity of human activities conducted in the streets’ pedestrian space. In Yogyakarta, one of the streets shown diversity of human activities is Jalan Kemasan. This study attempts to determine the physical factors of pedestrian space affecting the livability in Jalan Kemasan Yogyakarta through spatial analysis. Spatial analysis was performed by overlay technique between liveable point (activity diversity) distribution map and variable distribution map. Those physical pedestrian space research variable included element of shading, street vendors, building setback, seat location, divider between street and pedestrian way, and mixed use building function. More diverse the activity of one variable, then those variable are more affected then others. Overlay result then strengthened by field observation to qualitatively ensure the deduction. In the end, this research will provide valuable input for street and pedestrian space planning that is comfortable for human activities.

Silicide/Silicon Heterointerfaces, Reaction Kinetics and Ultra-short Channel Devices

NASA Astrophysics Data System (ADS)

Tang, Wei

Nickel silicide is one of the electrical contact materials widely used on very large scale integration (VLSI) of Si devices in microelectronic industry. This is because the silicide/silicon interface can be formed in a highly controlled manner to ensure reproducibility of optimal structural and electrical properties of the metal-Si contacts. These advantages can be inherited to Si nanowire (NW) field-effect transistors (FET) device. Due to the technological importance of nickel silicides, fundamental materials science of nickel silicides formation (Ni-Si reaction), especially in nanoscale, has raised wide interest and stimulate new insights and understandings. In this dissertation, in-situ transmission electron microscopy (TEM) in combination with FET device characterization will be demonstrated as useful tools in nano-device fabrication as well as in gaining insights into the process of nickel silicide formation. The shortest transistor channel length (17 nm) fabricated on a vapor-liquid-solid (VLS) grown silicon nanowire (NW) has been demonstrated by controlled reaction with Ni leads on an in-situ transmission electron microscope (TEM) heating stage at a moderate temperature of 400 ºC. NiSi2 is the leading phase, and the silicide-silicon interface is an atomically sharp type-A interface. At such channel lengths, high maximum on-currents of 890 (microA/microm) and a maximum transconductance of 430 (microS/microm) were obtained, which pushes forward the performance of bottom-up Si NW Schottky barrier field-effect transistors (SB-FETs). Through accurate control over the silicidation reaction, we provide a systematic study of channel length dependent carrier transport in a large number of SB-FETs with channel lengths in the range of (17 nm -- 3.6 microm). Our device results corroborate with our transport simulations and reveal a characteristic type of short channel effects in SB-FETs, both in on- and off-state, which is different from that in conventional MOSFETs

Evaluation of the focused approach to pedestrian safety program

DOT National Transportation Integrated Search

2009-02-02

This report summarizes the results of an evaluation of the Federal Highway Administration (FHWA) Focused Approach to Pedestrian Safety Program. The study was done by the Volpe National Transportation Systems Center at the request of the FHWA Office o...

Linking pedestrian flow characteristics with stepping locomotion

NASA Astrophysics Data System (ADS)

Wang, Jiayue; Boltes, Maik; Seyfried, Armin; Zhang, Jun; Ziemer, Verena; Weng, Wenguo

2018-06-01

While properties of human traffic flow are described by speed, density and flow, the locomotion of pedestrian is based on steps. To relate characteristics of human locomotor system with properties of human traffic flow, this paper aims to connect gait characteristics like step length, step frequency, swaying amplitude and synchronization with speed and density and thus to build a ground for advanced pedestrian models. For this aim, observational and experimental study on the single-file movement of pedestrians at different densities is conducted. Methods to measure step length, step frequency, swaying amplitude and step synchronization are proposed by means of trajectories of the head. Mathematical models for the relations of step length or frequency and speed are evaluated. The problem how step length and step duration are influenced by factors like body height and density is investigated. It is shown that the effect of body height on step length and step duration changes with density. Furthermore, two different types of step in-phase synchronization between two successive pedestrians are observed and the influence of step synchronization on step length is examined.

Analysis on influencing factors and decision-making of pedestrian crossing at intersections

NASA Astrophysics Data System (ADS)

Liu, Likun; Wang, Ziyang

2017-10-01

The city signal intersection always has complex traffic flow and many traffic accidents. As vulnerable participants, the proportion of traffic accidents involving pedestrians remain high. And a lot of insecure crossing behavior seriously reduce the safety of the intersection. Therefore, it is necessary to carry out in-depth study on the traversing characteristics of pedestrians, reveal the inherent laws of pedestrian crossing, and then put forward targeted measures to improve pedestrian traffic environment, protect pedestrian crossing safety and improve traffic efficiency.

Identification of reluctant factors in using footpaths based on the pedestrians' perception

NASA Astrophysics Data System (ADS)

Hadiyanto, Wahyu; Handayani, Dewi; Yulianto, Budi

2017-06-01

Footpath is a path intended particularly for pedestrians to avoid any conflicts with motor vehicles. However in reality, most of the pedestrians are unwilling to use paths and they prefer to walk on the roads. This research was conducted with the aim to identify the existing condition of pedestrian footpaths based on field observations and to determine the factors that cause the pedestrians are reluctant to walk on the trails. The method used to investigate the pedestrians' perception was by distributing questionnaires to the pedestrians. The results of this study found that the factors that caused the pedestrians did not want to use footpaths were the footpath width, the existence of barriers and obstacles, unstable height (not continuous), damaged surface, non-standard driveway that intersects sidewalk, suboptimal function of ramp, transverse steep slope, and the absence of bollard that could protect footpaths from the access of motorcycles.

Young drivers' perception of adult and child pedestrians in potential street-crossing situations.

PubMed

Ābele, Līva; Haustein, Sonja; Møller, Mette

2018-04-03

Despite overall improvements in road traffic safety, pedestrian accidents continue to be a serious public health problem. Due to lack of experience, limited cognitive and motoric skills, and smaller size, children have a higher injury risk as pedestrians than adults. To what extent drivers adjust their driving behaviour to children's higher vulnerability is largely unknown. To determine whether young male drivers' behaviour and scanning pattern differs when approaching a child and an adult pedestrian in a potential street-crossing situation, sixty-five young (18-24) male drivers' speed, lateral position and eye movements were recorded in a driving simulator. Results showed that fewer drivers responded by slowing down and that drivers had a higher driving speed when approaching a child pedestrian, although the time of the first fixation on both types of pedestrians was the same. However, drivers drove farther away from a child than an adult pedestrian. Additionally, fewer drivers who did not slow down fixated on the speedometer while approaching the child pedestrian. The results show that young drivers behave differently when approaching a child and an adult pedestrian, though not in a way that appropriately accounts for the limitations of a child pedestrian. A better understanding of how drivers respond to different types of pedestrians and why could contribute to the development of pedestrian detection and emergency braking systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Pedestrian facilities users guide : providing safety and mobility

DOT National Transportation Integrated Search

2002-03-01

The Guide provides information on how to identify safety and mobility needs of pedestrians within roadway rights-of-way. Chapter 1 provides an overview of the creation of a walkable environment. Chepter 2 describes basic pedestrian crash trends and t...

Spatial and temporal patterns of North Carolina pedestrian and bicycle plans.

PubMed

Aytur, Semra A; Rodriguez, Daniel A; Kerr, Zachary Y; Ji, Kai; Evenson, Kelly R

2013-01-01

Pedestrian and bicycle plans support community-level physical activity. In North Carolina, pedestrian/bicycle plans are becoming more prevalent. However, no studies have examined the spatial and temporal diffusion of pedestrian/bicycle plans. This study assessed (a) temporal trends associated with municipal pedestrian/bicycle planning from 1974 to 2011 and (b) spatial patterns associated with municipal plans, specifically, whether the publication of a pedestrian/bicycle plan in a given year was associated with the number of neighboring municipalities with plans. North Carolina from 1974 to 2011. The main outcome was date of publication of all North Carolina municipal pedestrian and bicycle plans (1974-2011). We calculated Euclidean distances from each municipality center to all other municipality centers to derive whether municipalities were within 20 and 50 miles of each other. Sociodemographic covariates (eg, education, grant funding status, poverty, urbanicity, racial composition, population size, population growth) were collected from the US Census of Population (1980-2010) and the American Community Survey (2006-2010). Time series models fitted by generalized estimating equations were used to assess relationships between plan presence and the temporal and spatial predictor variables. The number of pedestrian and bicycle plans significantly increased over time, especially after 2006 when a state grant funding program was initiated. Unadjusted models indicated that municipalities were significantly more likely to have a pedestrian plan if higher numbers of neighboring municipalities had pedestrian plans. After adjustment for sociodemographic covariates and funding source, this relationship was attenuated but remained statistically significant. For bicycle plans, no significant associations were observed between plan presence and the number of neighboring municipalities with bicycle plans in adjusted models. Findings from this study can be used to generate

Spatial Analysis of Urban Form and Pedestrian Exposure to Traffic Noise

PubMed Central

Sheng, Ni; Tang, U. Wa

2011-01-01

In the Macao Peninsula, the high population density (49,763 inhabitants/km2) and the lack of control over the number of vehicles (460 vehicles/km) have led to an increase in urban pollution. To provide useful information to local government and urban planners, this paper investigates the spatial distribution of traffic noise in the Macao Peninsula. The interactions among urban form, traffic flow and traffic noise are addressed. Considering the spatial nature of urban geometry and traffic, a high-resolution GIS-based traffic noise model system is applied. Results indicate that the Macao Peninsula has fallen into a situation of serious traffic noise pollution. About 60% of traffic noise levels along the major pedestrian sidewalks in the evening peak hour exceed the National Standard of 70 dB(A) in China. In particular, about 21% of traffic noise levels along the pedestrian sidewalks are above the National Standard by 5 dB(A). Noticeably, the high pedestrian exposure to traffic noise in the historical urban area reduces the comfort of tourists walking in the historic centre and is ruining the reputation of the area as a World Cultural Heritage site. PMID:21776213

Spatial analysis of urban form and pedestrian exposure to traffic noise.

PubMed

Sheng, Ni; Tang, U Wa

2011-06-01

In the Macao Peninsula, the high population density (49,763 inhabitants/km2) and the lack of control over the number of vehicles (460 vehicles/km) have led to an increase in urban pollution. To provide useful information to local government and urban planners, this paper investigates the spatial distribution of traffic noise in the Macao Peninsula. The interactions among urban form, traffic flow and traffic noise are addressed. Considering the spatial nature of urban geometry and traffic, a high-resolution GIS-based traffic noise model system is applied. Results indicate that the Macao Peninsula has fallen into a situation of serious traffic noise pollution. About 60% of traffic noise levels along the major pedestrian sidewalks in the evening peak hour exceed the National Standard of 70 dB(A) in China. In particular, about 21% of traffic noise levels along the pedestrian sidewalks are above the National Standard by 5 dB(A). Noticeably, the high pedestrian exposure to traffic noise in the historical urban area reduces the comfort of tourists walking in the historic centre and is ruining the reputation of the area as a World Cultural Heritage site.

Measuring accident risk exposure for pedestrians in different micro-environments.

PubMed

Lassarre, Sylvain; Papadimitriou, Eleonora; Yannis, George; Golias, John

2007-11-01

Pedestrians are mainly exposed to the risk of road accident when crossing a road in urban areas. Traditionally in the road safety field, the risk of accident for pedestrian is estimated as a rate of accident involvement per unit of time spent on the road network. The objective of this research is to develop an approach of accident risk based on the concept of risk exposure used in environmental epidemiology, such as in the case of exposure to pollutants. This type of indicator would be useful for comparing the effects of urban transportation policy scenarios on pedestrian safety. The first step is to create an indicator of pedestrians' exposure, which is based on motorised vehicles' "concentration" by lane and also takes account of traffic speed and time spent to cross. This is applied to two specific micro-environments: junctions and mid-block locations. A model of pedestrians' crossing behaviour along a trip is then developed, based on a hierarchical choice between junctions and mid-block locations and taking account of origin and destination, traffic characteristics and pedestrian facilities. Finally, a complete framework is produced for modelling pedestrians' exposure in the light of their crossing behaviour. The feasibility of this approach is demonstrated on an artificial network and a first set of results is obtained from the validation of the models in observational studies.

A Macroscopic Approach to the Lane Formation Phenomenon in Pedestrian Counterflow

NASA Astrophysics Data System (ADS)

Xiong, Tao; Zhang, Peng; Wong, S. C.; Shu, Chi-Wang; Zhang, Meng-Ping

2011-10-01

We simulate pedestrian counterflow by adopting an optimal path-choice strategy and a recently observed speed-density relationship. Although the whole system is symmetric, the simulation demonstrates the segregation and formation of many walking lanes for two groups of pedestrians. The symmetry breaking is most likely triggered by a small numerical viscosity or “noise", and the segregation is associated with the minimization of travel time. The underlying physics can be compared with the “optimal self-organization" mechanism in Helbing's social force model, by which driven entities in an open system tend to minimize their interaction to enable them to reach some ordering state.

Universal Power Law Governing Pedestrian Interactions

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

Karamouzas, Ioannis; Skinner, Brian; Guy, Stephen J.

2014-12-01

Human crowds often bear a striking resemblance to interacting particle systems, and this has prompted many researchers to describe pedestrian dynamics in terms of interaction forces and potential energies. The correct quantitative form of this interaction, however, has remained an open question. Here, we introduce a novel statistical-mechanical approach to directly measure the interaction energy between pedestrians. This analysis, when applied to a large collection of human motion data, reveals a simple power-law interaction that is based not on the physical separation between pedestrians but on their projected time to a potential future collision, and is therefore fundamentally anticipatory inmore » nature. Remarkably, this simple law is able to describe human interactions across a wide variety of situations, speeds, and densities. We further show, through simulations, that the interaction law we identify is sufficient to reproduce many known crowd phenomena.« less

Crash avoidance needs and countermeasure profiles for safety applications based on light-vehicle-to-pedestrian communications

DOT National Transportation Integrated Search

2016-08-01

This research supports establishing an updated understanding of the pedestrian crash problem and defining a way to connect the crash problem with vehicle-to-pedestrian (V2P) communication crash avoidance technology. It describes 5 priority pre-crash ...

Epidemiology of Pedestrian-Motor Vehicle Fatalities and Injuries, 2006-2015.

PubMed

Chong, Shu-Ling; Chiang, Li-Wei; Allen, John Carson; Fleegler, Eric William; Lee, Lois Kaye

2018-07-01

Pedestrian road safety remains a public health priority. The objective of this study is to describe trends in fatalities and injuries after pedestrian-motor vehicle collisions in the U.S. and identify associated risk factors for pedestrian fatalities. This is a cross-sectional study of U.S. pedestrian-motor vehicle collisions from 2006 to 2015 (performed in 2017). Pedestrian fatality and injury data were obtained from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System and National Automotive Sampling System General Estimates System. Frequencies of fatalities, injuries, and associated characteristics were calculated. Multivariable logistic regression was performed for risk of fatality, controlling for demographic and crash-related factors. There were 47,789 pedestrian fatalities and 674,414 injuries during the 10-year study period. Fatality rates were highest among the elderly aged 85 years and older (2.95/100,000 population), whereas injury rates were highest for those aged 15-19 years (35.23/100,000 population). Predictors associated with increased risk for death include the following: male sex (AOR=1.36, 95% CI=1.15, 1.62), age ≥65 years (AOR=3.44, 95% CI=2.62, 4.50), alcohol involvement (AOR=2.63, 95% CI=1.88, 3.67), collisions after midnight (AOR=5.21, 95% CI=3.20, 8.49), at non-intersections (AOR=2.76, 95% CI=2.21, 3.45), and involving trucks (AOR=2.15, 95% CI=1.16, 3.97) and buses (AOR=5.82, 95% CI=3.67, 9.21). Potentially modifiable factors are associated with increased risk of death after pedestrian-motor vehicle collisions. Interventions including elder-friendly intersections and increasing visibility of pedestrians may aid in decreasing pedestrian injuries and deaths. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Optical transmission modules for multi-channel superconducting quantum interference device readouts.

PubMed

Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong

2013-12-01

We developed an optical transmission module consisting of 16-channel analog-to-digital converter (ADC), digital-noise filter, and one-line serial transmitter, which transferred Superconducting Quantum Interference Device (SQUID) readout data to a computer by a single optical cable. A 16-channel ADC sent out SQUID readouts data with 32-bit serial data of 8-bit channel and 24-bit voltage data at a sample rate of 1.5 kSample/s. A digital-noise filter suppressed digital noises generated by digital clocks to obtain SQUID modulation as large as possible. One-line serial transmitter reformed 32-bit serial data to the modulated data that contained data and clock, and sent them through a single optical cable. When the optical transmission modules were applied to 152-channel SQUID magnetoencephalography system, this system maintained a field noise level of 3 fT/√Hz @ 100 Hz.

[Pedestrian accidents].

PubMed

Bugmann, I; Röthlisberger, M; Friederich, N F; Müller, W

1998-12-03

The epidemiology of non-traffic-related, pedestrian injuries in the winter sports resort of Arosa (Switzerland) between 1968 and 1995 (beginning december to end april) was studied. A total of 2813 patients (1140 male and 1673 female patients) with 3010 injuries was surveyed in a general practice. The study showed in the examined period not only an increasing number of injuries and a culmination in February, but also a higher risk for females (60 versus 40 per cent) and an increasing incidence with age. 6% of all patients had more than one injury and 5% required hospitalization. Most pedestrians had injuries of the upper and lower extremity; fracture of the distal radius was the most often diagnosed injury, followed by distortions of the foot and wrist and fractures of the ankle. For accident prevention it is important, that the authorities do not abstain from mechanical cleaning of walking surfaces as soon as they become slippery and from giving out warnings via the mass media. For outdoor walking we postulate boots for ankle protection. The results are discussed and compared with already existing publications.

[Automobile versus pedestrian accidents analysis by fixed-parameters computer simulation].

PubMed

Mao, Ming-Yuan; Chen, Yi-Jiu; Liu, Ning-Guo; Zou, Dong-Hua; Liu, Jun-Yong; Jin, Xian-Long

2008-04-01

Using computer simulation to analyze the effects of speed, type of automobile and impacted position on crash-course and injuries of pedestrians in automobile vs. pedestrian accidents. Automobiles (bus, minibus, car and truck) and pedestrian models were constructed with multi-body dynamics computing method. The crashes were simulated at different impact speeds (20, 30, 40, 50 and 60 km/h) and different positions (front, lateral and rear of pedestrians). Crash-courses and their biomechanical responses were studied. If the type of automobile and impact position were the same, the crash-courses were similar (impact speed < or = 60 km/h). There were some characteristics in the head acceleration, upper neck axial force and leg axial force. Multi-body dynamics computer simulation of crash can be applied to analyze crash-course and injuries (head, neck and leg) of pedestrians.

Risk factors in road crossing among elderly pedestrians and readiness to adopt safe behavior in socio-economic comparison.

PubMed

Rosenbloom, Tova; Sapir-Lavid, Yael; Perlman, Amotz

2016-08-01

This research examines the Health Promotion Behavior (HPB) models regarding elderly pedestrians' behaviors and attitudes. We studied cognitive-psychological variables, such as risk estimation, self-efficacy and demographic variables and compared elderly pedestrians' attitudes and behaviors in a city with higher socio-economic level (Tel Aviv) versus a city with low socio-economic level (Beer Sheva). We expected to find more problematic behaviors among elderly pedestrians in the low socio-economic city compared to the high socio-economic city, and also less feeling of self-efficacy, and lessened awareness of the risks, that leads to lessened willingness to adopt preventive behaviors. The research was conducted in two studies. The first study was based on observations on 2591 pedestrians in six similar crosswalks in both cities. It revealed that pedestrians in the high socio-economic city demonstrated safer road crossing patterns than in the low socio-economic city and that elderly pedestrians reveal safer crossing patterns than younger pedestrians. We found an interaction of location and age due to greater gap of safe behaviors of elderly and young pedestrians in the high socio-economic city than in the low socio-economic city. In Tel Aviv elderly adhere to the crossing rules much more than the young while in Beer Sheva elderly and young people are almost similar in their crossing patterns. The second study used questionnaires that have been completed by 143 elderly in both cities. The questionnaires referred to (a) demographic variables such as gender, age, marital status, education, socio-economic level, (b) variables related to the affiliation to the main culture such as migration, date of migration, knowledge in Hebrew (local language) and connectivity to media and (c) cognitive as well as psychological variables related to the decline to adopt healthy behaviors based on Schwarzer and Fuchs (1995). This part also indicated that elderly in Tel Aviv have higher

Automatic Pedestrian Crossing Detection and Impairment Analysis Based on Mobile Mapping System

NASA Astrophysics Data System (ADS)

Liu, X.; Zhang, Y.; Li, Q.

2017-09-01

Pedestrian crossing, as an important part of transportation infrastructures, serves to secure pedestrians' lives and possessions and keep traffic flow in order. As a prominent feature in the street scene, detection of pedestrian crossing contributes to 3D road marking reconstruction and diminishing the adverse impact of outliers in 3D street scene reconstruction. Since pedestrian crossing is subject to wearing and tearing from heavy traffic flow, it is of great imperative to monitor its status quo. On this account, an approach of automatic pedestrian crossing detection using images from vehicle-based Mobile Mapping System is put forward and its defilement and impairment are analyzed in this paper. Firstly, pedestrian crossing classifier is trained with low recall rate. Then initial detections are refined by utilizing projection filtering, contour information analysis, and monocular vision. Finally, a pedestrian crossing detection and analysis system with high recall rate, precision and robustness will be achieved. This system works for pedestrian crossing detection under different situations and light conditions. It can recognize defiled and impaired crossings automatically in the meanwhile, which facilitates monitoring and maintenance of traffic facilities, so as to reduce potential traffic safety problems and secure lives and property.

Effects of Different Levels of Refractive Blur on Nighttime Pedestrian Visibility.

PubMed

Wood, Joanne M; Marszalek, Ralph; Carberry, Trent; Lacherez, Philippe; Collins, Michael J

2015-07-01

The aim of this study was to systematically investigate the effect of different levels of refractive blur and driver age on nighttime pedestrian recognition and determine whether clothing that has been shown to improve pedestrian conspicuity is robust to the effects of blur. Nighttime pedestrian recognition was measured for 24 visually normal participants (12 younger mean = 24.9 ± 4.5 years and 12 older adults mean = 77.6 ± 5.7 years) for three levels of binocular blur (+0.50 diopter [D], +1.00 D, +2.00 D) compared with baseline (optimal refractive correction). Pedestrians walked in place on a closed road circuit and wore one of three clothing conditions: everyday clothing, a retro-reflective vest, and retro-reflective tape positioned on the extremities in a configuration that conveyed biological motion (known as "biomotion"); the order of conditions was randomized among participants. Pedestrian recognition distances were recorded for each blur and pedestrian clothing combination while participants drove an instrumented vehicle around a closed road course. The recognition distances for pedestrians were significantly reduced (P < 0.05) by all levels of blur compared with baseline. Pedestrians wearing biomotion clothing were recognized at significantly longer distances than for the other clothing configurations in all blur conditions. However, these effects were smaller for the older adults, who had much shorter recognition distances for all conditions tested. In summary, even small amounts of blur had a significant detrimental effect on nighttime pedestrian recognition. Biomotion retro-reflective clothing was effective, even under moderately degraded visibility conditions, for both young and older drivers.

Improving pedestrian facilities in congested urban areas: a case study of Chennai city

NASA Astrophysics Data System (ADS)

Subramanyam, B.; Prasanna Kumar, R.

2017-07-01

Traffic congestion and lack of public pedestrian space are some problems faced by most urban metropolises. Conventionally walking has been a mode of transportation in Indian cities. The percentage of pedestrians may vary from 16 to 57 depending upon the city. Encounters between vehicular traffic and pedestrian traffic are at its rise currently. Rapid industrialization and urbanization in India has resulted in neglecting of pedestrian facilities. Consequently pedestrian are at greater risk for their safety more especially in the commercial zones of large cities. A change in perspective spotlight will create a sense of awareness that the pedestrian traffic is also vital as the vehicular traffic. Soothing the traffic would moderately cut the driving expediency but the pedestrians will get a much safer and peaceful route to their terminuses. Safety and comfort are the two pans of a balance while considering the pedestrian traffic. Considering these aspects, this study deals a study in improving pedestrian facilities by analysing the existing skeleton of the selected locations. The adequacy of facility is checked based on IRC latest guidelines and counteractive measures are postulated.

Pedestrian self-reported use of smart phones: Positive attitudes and high exposure influence intentions to cross the road while distracted.

PubMed

Lennon, Alexia; Oviedo-Trespalacios, Oscar; Matthews, Sarah

2017-01-01

Pedestrian crashes are an important issue globally as pedestrians are a highly vulnerable road user group, accounting for approximately 35% of road deaths worldwide each year. In highly motorised countries, pedestrian distraction by hand held technological devices appears to be an increasing factor in such crashes. An online survey (N=363) was conducted to 1) obtain prevalence information regarding the extent to which people cross the road while simultaneously using mobile phones for potentially distracting activities; 2) identify whether younger adult pedestrians are more exposed to/at risk of injury due to this cause than older adults; and 3) explore whether the Theory of Planned Behaviour (TPB) might provide insight into the factors influencing the target behaviours. Self-reported frequency of using a smart phone for three levels of distraction (visual and cognitive-texting/internet; cognitive only- voice calls; audio only-listening to music) while crossing the road was collected. Results indicated that about 20% of the sample had high exposure to smart phone use while crossing, especially 18-30year olds who were significantly more likely than other age groups to report frequent exposure. TPB constructs of Attitude, Subjective Norm, and Perceived Behavioural Control significantly predicted intentions to use a smart phone while crossing the road, accounting for 62% of variance in Intentions for the entire sample, and 54% of the variance for 18-30year olds. Additional variables of Mobile Phone Involvement and Group Norms provided an additional significant 6% of the variance explained for both groups. Attitude was by far the strongest predictor for both the whole sample and for 18-30year olds, accounting for 38% and 41% explained variance, respectively. This suggests that pedestrians with positive attitudes towards using their smart phones while crossing the road have stronger intentions to do so. Moreover, high exposure was associated with stronger intentions to

Potential field cellular automata model for pedestrian flow

NASA Astrophysics Data System (ADS)

Zhang, Peng; Jian, Xiao-Xia; Wong, S. C.; Choi, Keechoo

2012-02-01

This paper proposes a cellular automata model of pedestrian flow that defines a cost potential field, which takes into account the costs of travel time and discomfort, for a pedestrian to move to an empty neighboring cell. The formulation is based on a reconstruction of the density distribution and the underlying physics, including the rule for resolving conflicts, which is comparable to that in the floor field cellular automaton model. However, we assume that each pedestrian is familiar with the surroundings, thereby minimizing his or her instantaneous cost. This, in turn, helps reduce the randomness in selecting a target cell, which improves the existing cellular automata modelings, together with the computational efficiency. In the presence of two pedestrian groups, which are distinguished by their destinations, the cost distribution for each group is magnified due to the strong interaction between the two groups. As a typical phenomenon, the formation of lanes in the counter flow is reproduced.

Influence of approaching tram on behaviour of pedestrians in signalised crosswalks in Poland.

PubMed

Kruszyna, Maciej; Rychlewski, Jeremi

2013-06-01

Research done in two Polish cities has uncovered an influence of an approaching tram on pedestrian behaviour. The measurements were done by counting pedestrians waiting for a green signal, crossing on red signal safely, or crossing on red signal taking a risk of being hit by a car, differentiating between pedestrians attempting to board a public transport vehicle and other pedestrians. It was expected, that pedestrian behaviour might be influenced by traffic control predictability, therefore two cities were chosen for the task: Wrocław with fixed time traffic control and Poznań with a majority of traffic responsive traffic signals. Data from the measurements was compared in order to find behaviour patterns - the comparison led to a conclusion, that an attempt to get on board of an incoming public transport vehicle can be a major cause for pedestrians to violate a red signal, including an increase of unsafe behaviour. These pedestrians may provoke other pedestrians to cross on a red signal. On the other hand if traffic control guarantees boarding the public transport vehicle, passengers-to-be may be even more obedient than other pedestrians. Copyright © 2013 Elsevier Ltd. All rights reserved.

Capacity analysis of pedestrian facilities involving individuals with disabilities.

DOT National Transportation Integrated Search

2015-08-31

Walking facilities are important infrastructures that must be designed to accommodate the behavior of pedestrians in order to be effective. Heterogeneity in pedestrian composition is one important factor generally overlooked in walking facility desig...

Improving Pedestrian Access to Transit: City of Gresham's Ped-to-MAX Program

DOT National Transportation Integrated Search

1999-01-01

Accommodating multi-modal travel on high speed arterials is a challenge, : particularly in Gresham where numerous arterials transect the city, creating : barriers to pedestrians, bicyclists, and transit users. The "Ped-to-MAX" : program was created t...

Pedestrian Detection and Tracking from Low-Resolution Unmanned Aerial Vehicle Thermal Imagery

PubMed Central

Ma, Yalong; Wu, Xinkai; Yu, Guizhen; Xu, Yongzheng; Wang, Yunpeng

2016-01-01

Driven by the prominent thermal signature of humans and following the growing availability of unmanned aerial vehicles (UAVs), more and more research efforts have been focusing on the detection and tracking of pedestrians using thermal infrared images recorded from UAVs. However, pedestrian detection and tracking from the thermal images obtained from UAVs pose many challenges due to the low-resolution of imagery, platform motion, image instability and the relatively small size of the objects. This research tackles these challenges by proposing a pedestrian detection and tracking system. A two-stage blob-based approach is first developed for pedestrian detection. This approach first extracts pedestrian blobs using the regional gradient feature and geometric constraints filtering and then classifies the detected blobs by using a linear Support Vector Machine (SVM) with a hybrid descriptor, which sophisticatedly combines Histogram of Oriented Gradient (HOG) and Discrete Cosine Transform (DCT) features in order to achieve accurate detection. This research further proposes an approach for pedestrian tracking. This approach employs the feature tracker with the update of detected pedestrian location to track pedestrian objects from the registered videos and extracts the motion trajectory data. The proposed detection and tracking approaches have been evaluated by multiple different datasets, and the results illustrate the effectiveness of the proposed methods. This research is expected to significantly benefit many transportation applications, such as the multimodal traffic performance measure, pedestrian behavior study and pedestrian-vehicle crash analysis. Future work will focus on using fused thermal and visual images to further improve the detection efficiency and effectiveness. PMID:27023564

Pedestrian Detection and Tracking from Low-Resolution Unmanned Aerial Vehicle Thermal Imagery.

PubMed

Ma, Yalong; Wu, Xinkai; Yu, Guizhen; Xu, Yongzheng; Wang, Yunpeng

2016-03-26

Driven by the prominent thermal signature of humans and following the growing availability of unmanned aerial vehicles (UAVs), more and more research efforts have been focusing on the detection and tracking of pedestrians using thermal infrared images recorded from UAVs. However, pedestrian detection and tracking from the thermal images obtained from UAVs pose many challenges due to the low-resolution of imagery, platform motion, image instability and the relatively small size of the objects. This research tackles these challenges by proposing a pedestrian detection and tracking system. A two-stage blob-based approach is first developed for pedestrian detection. This approach first extracts pedestrian blobs using the regional gradient feature and geometric constraints filtering and then classifies the detected blobs by using a linear Support Vector Machine (SVM) with a hybrid descriptor, which sophisticatedly combines Histogram of Oriented Gradient (HOG) and Discrete Cosine Transform (DCT) features in order to achieve accurate detection. This research further proposes an approach for pedestrian tracking. This approach employs the feature tracker with the update of detected pedestrian location to track pedestrian objects from the registered videos and extracts the motion trajectory data. The proposed detection and tracking approaches have been evaluated by multiple different datasets, and the results illustrate the effectiveness of the proposed methods. This research is expected to significantly benefit many transportation applications, such as the multimodal traffic performance measure, pedestrian behavior study and pedestrian-vehicle crash analysis. Future work will focus on using fused thermal and visual images to further improve the detection efficiency and effectiveness.

Time-to-collision analysis of pedestrian and pedal-cycle accidents for the development of autonomous emergency braking systems.

PubMed

Lenard, James; Welsh, Ruth; Danton, Russell

2018-06-01

The aim of this study was to describe the position of pedestrians and pedal cyclists relative to the striking vehicle in the 3 s before impact. This information is essential for the development of effective autonomous emergency braking systems and relevant test conditions for consumer ratings. The UK RAIDS-OTS study provided 175 pedestrian and 127 pedal-cycle cases based on in-depth, at-scene investigations of a representative sample of accidents in 2000-2010. Pedal cyclists were scattered laterally more widely than pedestrians (90% of cyclists within around ±80° compared to ±20° for pedestrians), however their distance from the striking vehicle in the seconds before impact was no greater (90% of cyclists within 42 m at 3 s compared to 50 m for pedestrians). This data is consistent with a greater involvement of slow moving vehicles in cycle accidents. The implication of the results is that AEB systems for cyclists require almost complete 180° side-to-side vision but do not need a longer distance range than for pedestrians. Copyright © 2018 Elsevier Ltd. All rights reserved.

Study on bi-directional pedestrian movement using ant algorithms

NASA Astrophysics Data System (ADS)

Sibel, Gokce; Ozhan, Kayacan

2016-01-01

A cellular automata model is proposed to simulate bi-directional pedestrian flow. Pedestrian movement is investigated by using ant algorithms. Ants communicate with each other by dropping a chemical, called a pheromone, on the substrate while crawling forward. Similarly, it is considered that oppositely moving pedestrians drop ‘visual pheromones’ on their way and the visual pheromones might cause attractive or repulsive interactions. This pheromenon is introduced into modelling the pedestrians’ walking preference. In this way, the decision-making process of pedestrians will be based on ‘the instinct of following’. At some densities, the relationships of velocity-density and flux-density are analyzed for different evaporation rates of visual pheromones. Lane formation and phase transition are observed for certain evaporation rates of visual pheromones.

Materials challenges for repeatable RF wireless device reconfiguration with microfluidic channels

NASA Astrophysics Data System (ADS)

Griffin, Anthony S.; Sottos, Nancy R.; White, Scott R.

2018-03-01

Recently, adaptive wireless devices have utilized displacement of EGaIn within microchannels as an electrical switching mechanism to enable reconfigurable electronics. Device reconfiguration using EGaIn in microchannels overcomes many challenges encountered by more traditional reconfiguration mechanisms such as diodes and microelectromechanical systems (MEMS). Reconfiguration using EGaIn is severely limited by undesired permanent shorting due to retention of the liquid in microchannels caused by wetting and rapid oxide skin formation. Here, we investigate the conditions which prevent repeatable electrical switching using EGaIn in microchannels. Initial contact angle tests of EGaIn on epoxy surfaces demonstrate the wettability of EGaIn on flat surfaces. SEM cross-sections of microchannels reveal adhesion of EGaIn residue to channel walls. Micro-computed tomography (microCT) scans of provide volumetric measurements of EGaIn remaining inside channels after flow cycling. Non-wetting coatings are proposed as materials based strategy to overcome these issues in future work.

Step styles of pedestrians at different densities

NASA Astrophysics Data System (ADS)

Wang, Jiayue; Weng, Wenguo; Boltes, Maik; Zhang, Jun; Tordeux, Antoine; Ziemer, Verena

2018-02-01

Stepping locomotion is the basis of human movement. The investigation of stepping locomotion and its affecting factors is necessary for a more realistic knowledge of human movement, which is usually referred to as walking with equal step lengths for the right and left leg. To study pedestrians’ stepping locomotion, a set of single-file movement experiments involving 39 participants of the same age walking on a highly curved oval course is conducted. The microscopic characteristics of the pedestrians including 1D Voronoi density, speed, and step length are calculated based on a projected coordinate. The influence of the projection lines with different radii on the measurement of these quantities is investigated. The step lengths from the straight and curved parts are compared using the Kolmogorov-Smirnov test. During the experiments, six different step styles are observed and the proportions of different step styles change with the density. At low density, the main step style is the stable-large step style and the step lengths of one pedestrian are almost constant. At high density, some pedestrians adjust and decrease their step lengths. Some pedestrians take relatively smaller and larger steps alternately to adapt to limited space.

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.

Severity of vehicle bumper location in vehicle-to-pedestrian impact accidents.

PubMed

Matsui, Yasuhiro; Hitosugi, Masahito; Mizuno, Koji

2011-10-10

Pedestrian protection is one of the key topics for safety measures in traffic accidents all over the world. To analyze the relation between the collision site of the vehicle bumper and the severity of the lower extremity injuries, we performed biomechanical experiments. We compared the applied external force and the risks of subsequent injuries between the impact of the center and side positions of the front bumper. These comparisons were performed by practical impact tests with eight typical different types of cars which were typical of the current vehicle fleets. The tests were made using the TRL legform impactor which was a mechanical substitute of a pedestrian lower extremity. The TRL impactor is used all over the world for assessing the safety of car bumpers. It was found that the risks of lower extremity injuries in the impacts at the side positions, in front of the vehicle's side member, were significantly higher than those at the center. In the tests, we found that foam materials around the rigid front cross member had a significant effect on reducing the lower extremity injury risks and especially tibia fracture risk against vehicle bumper center collisions, but had little effect at the sides of the bumper over the vehicle's side members where the foam was thinner. We also found that the front shape of the vehicle affected the risk of ligaments injuries. According to these results, the information of impact locations of cars in vehicle-to-pedestrian traffic accidents is valuable for clinicians to diagnose patients with lower extremity injuries in traffic accidents and for forensic pathologists to analyze the accident reconstruction. Furthermore, the results suggest that testing of the bumper area in front of the main longitudinal beams should be included in the car safety legislation to require pedestrian safety. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Scaling laws in granular flow and pedestrian flow

NASA Astrophysics Data System (ADS)

Chen, Shumiao; Alonso-Marroquin, Fernando; Busch, Jonathan; Hidalgo, Raúl Cruz; Sathianandan, Charmila; Ramírez-Gómez, Álvaro; Mora, Peter

2013-06-01

We use particle-based simulations to examine the flow of particles through an exit. Simulations involve both gravity-driven particles (representing granular material) and velocity-driven particles (mimicking pedestrian dynamics). Contact forces between particles include elastic, viscous, and frictional forces; and simulations use bunker geometry. Power laws are observed in the relation between flow rate and exit width. Simulations of granular flow showed that the power law has little dependence on the coefficient of friction. Polydisperse granular systems produced higher flow rates than those produced by monodisperse ones. We extend the particle model to include the main features of pedestrian dynamics: thoracic shape, shoulder rotation, and desired velocity oriented towards the exit. Higher desired velocity resulted in higher flow rate. Granular simulations always give higher flow rate than pedestrian simulations, despite the values of aspect ratio of the particles. In terms of force distribution, pedestrians and granulates share similar properties with the non-democratic distribution of forces that poses high risks of injuries in a bottleneck situation.

Trees as environmental modifier to improve street canyon for pedestrian activities in Muscat

NASA Astrophysics Data System (ADS)

Khudhayer, Wael A.; Shaaban, Awni K.; Sukor, Nur Sabahiah Abdul

2017-10-01

Street shading efficiency is a function of orientation and profile proportion of its height to width. Under high sun altitude conditions, minimization of solar irradiance within the urban environment may often be a significant criterion in urban design. This reduction in solar irradiance achieved when the obstruction angle is large (high H/W ratio, H=height, W=width). High H/W values often lessen the solar access to streets. The horizontal sprawl of Muscat region is an example of low H/W ratio represented the remarkable challenge that causes the lack of shading rates in the urban street. This characteristic proliferates the negative impact on the pedestrian activities in the urban street. This research aims to improve the morphology of the street to promote the pedestrian behavior. The amendment based on suggesting different configurations of trees to increase effective shading of the urban street in Muscat. The street canyon abstracted into a virtual elongated channel formed of floor and walls of equal heights on both sides. Four street orientations (E/W, N/S, NE/SW, NW/SE) and three H/W ratio (0.5,1 and 2) are considered sufficient representative of street typologies. A mathematical model developed for calculation of shading efficiency of each street canyon. The trees assumed in this study as canyon's modifier to adjust the low H/W ratio of a street canyon to a higher one. Local trees and other plants in Muscat were studied concerning their morphology. The analysis selected two case study in Muscat to investigate the shading performance of their street canyons subsequently propose the modifications to improve it. The research concluded that the suggested changes of the street canyon by using a particular type of trees could increase the H/W ratio of street canyon significantly.

Spatial-size scaling of pedestrian groups under growing density conditions

NASA Astrophysics Data System (ADS)

Zanlungo, Francesco; Brščić, Dražen; Kanda, Takayuki

2015-06-01

We study the dependence on crowd density of the spatial size, configuration, and velocity of pedestrian social groups. We find that, in the investigated density range, the extension of pedestrian groups in the direction orthogonal to that of motion decreases linearly with the pedestrian density around them, both for two- and three-person groups. Furthermore, we observe that at all densities, three-person groups walk slower than two-person groups, and the latter are slower than individual pedestrians, the differences in velocities being weakly affected by density. Finally, we observe that three-person groups walk in a V-shaped formation regardless of density, with a distance between the pedestrians in the front and back again almost independent of density, although the configuration appears to be less stable at higher densities. These findings may facilitate the development of more realistic crowd dynamics models and simulators.

Metal-Assisted Channel Stabilization: Disposition of a Single Histidine on the N-terminus of Alamethicin Yields Channels with Extraordinarily Long Lifetimes

PubMed Central

Noshiro, Daisuke; Asami, Koji; Futaki, Shiroh

2010-01-01

Abstract Alamethicin, a member of the peptaibol family of antibiotics, is a typical channel-forming peptide with a helical structure. The self-assembly of the peptide in the membranes yields voltage-dependent channels. In this study, three alamethicin analogs possessing a charged residue (His, Lys, or Glu) on their N-termini were designed with the expectation of stabilizing the transmembrane structure. A slight elongation of channel lifetime was observed for the Lys and Glu analogs. On the other hand, extensive stabilization of certain channel open states was observed for the His analog. This stabilization was predominantly observed in the presence of metal ions such as Zn2+, suggesting that metal coordination with His facilitates the formation of a supramolecular assembly in the membranes. Channel stability was greatly diminished by acetylation of the N-terminal amino group, indicating that the N-terminal amino group also plays an important role in metal coordination. PMID:20441743

Effects of Switching Behavior for the Attraction on Pedestrian Dynamics.

PubMed

Kwak, Jaeyoung; Jo, Hang-Hyun; Luttinen, Tapio; Kosonen, Iisakki

2015-01-01

Walking is a fundamental activity of our daily life not only for moving to other places but also for interacting with surrounding environment. While walking on the streets, pedestrians can be aware of attractions like shopping windows. They can be influenced by the attractions and some of them might shift their attention towards the attractions, namely switching behavior. As a first step to incorporate the switching behavior, this study investigates collective effects of switching behavior for an attraction by developing a behavioral model. Numerical simulations exhibit different patterns of pedestrian behavior depending on the strength of the social influence and the average length of stay. When the social influence is strong along with a long length of stay, a saturated phase can be defined at which all the pedestrians have visited the attraction. If the social influence is not strong enough, an unsaturated phase appears where one can observe that some pedestrians head for the attraction while others walk in their desired direction. These collective patterns of pedestrian behavior are summarized in a phase diagram by comparing the number of pedestrians who visited the attraction to the number of passersby near the attraction. Measuring the marginal benefits with respect to the strength of the social influence and the average length of stay enables us to identify under what conditions enhancing these variables would be more effective. The findings from this study can be understood in the context of the pedestrian facility management, for instance, for retail stores.