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• Importance of vehicular trajectory for sensing naturalistic instincts of the vehicles. • Instantaneous Perception Time is coined for quantifying vehicle attentiveness. • Safety thresholds for measuring the risk of rear-end collision. • Real time monitoring to check the performance of traffic stream. The present research work is initiated, probing for safety levels, evolving as an outcome of analysis of micro-level interactions due to naturalistic vehicular movements on Indian expressways. The research work reported here, devised a micro-level parameter, namely instant perception time (IPT) as a safety measure, which is a function of vehicular interactions. As a step towards deriving IPT, video-graphic surveys were conducted and traffic data was collected on two intercity Indian expressways. As a part of this work, first microscopic trajectory data was developed for capturing naturalistic driving behavior under heterogeneous traffic environment. Thereafter, hysteresis plots were developed between leader-follower pairs using relative speed and spacing between the vehicles. By means of the developed hysteresis plots, a novel approach for identification and quantifying chances of rear-end crashes using follower's Instantaneous perception time (IPT), is proposed in the present study. To study the IPT approach under different flow conditions, well-calibrated and validated simulation model is also developed using real trajectory data collected for the prevailing traffic conditions observed on the study sections. From the obtained IPTs using simulation model, three cluster ranges are delineated pertaining to different levels of risks of crashes. The cluster-analysis suggests that the least values of space-headway (m) and IPT (s) (space headway < 10.91 m, IPT < 5.61 s) at a given location shows most severe chances of rear-end collision. While, lower to moderate values indicate (with thresholds: space headway in the range 10.91–18.5 m; IPT 5.61–11.91 s), whereas higher values of IPT (more than 12 s) suggest the least chances of rear-end collision. The methodological approach, results and findings thus developed under naturalistic driving environment, presented here can be very useful in understanding the operational deficiencies of traffic streams, road geometry, coupled with safety assessment of traffic streams on uninterrupted roadway facilities. Furthermore, traffic control or geometry improvement related decisions can also be taken at different unsafe locations using IPT as a risk measure to enhance safety. [ABSTRACT FROM AUTHOR]

Connected and automated vehicles (CAVs) promise to change the transportation landscape with safer, faster and more energy-efficient mobility. However 100% CAV penetration may never be achieved, raising the question of how to ensure a productive co-existence of CAVs with conventional vehicles. In this paper, we address the problem of optimally controlling CAVs under mixed traffic conditions where both CAVs and human-driven vehicles (non-CAVs) travel on the roads. We specifically consider problems with such mixed traffic crossing an intersection without using explicit traffic signaling, the objective being to minimize energy consumption subject to a throughput maximization requirement while guaranteeing safety constraints. The impact of CAVs on overall energy consumption is investigated under different traffic scenarios as a function of the CAV penetration rate (i.e., the fraction of CAVs relative to all vehicles). Performance under traffic light control is used as a baseline for this study. Results are validated through simulation using MATLAB and VISSIM. The results indicate that the energy efficiency improvement becomes more significant as the CAV penetration rate increases, while the significance diminishes as traffic becomes heavier. [ABSTRACT FROM AUTHOR]

Narrow seat aisle is an important part of vehicle car interior, and previous studies on pedestrian dynamics in such area is still insufficient. To improve this situation, experiments of individual and single-file pedestrian movement were performed. Discussions were carried out from the aspect of walking speed, headways distance, and fundamental diagram. It is shown that walking speed of individual pedestrian grows exponentially fast to an asymptotic value as aisle width increases, and the width of 0.40 m is wide enough to allow a smooth walking. In the single-file movement, pedestrian walking speed can also be affected by headways distance and the predecessors. Also, existence of inactive pedestrian interferes the pedestrian flow, slowing down the flow rate or even causing a jam. Moreover, linear fitting models introduced in this paper, which link the motion of individual and single-file pedestrian, are able to well predict the movement speeds. This study will provides reference for the safety design of similar seat area in vehicle cars. [ABSTRACT FROM AUTHOR]

The last decade has seen a worldwide exponential increase in the use of mobile information systems, especially smartphones. This trend covers all areas of life, and also seems to include phone use while driving. In order to assess the scope of secondary task occupation, especially smartphone use while driving, observation studies from outside the car have been established as an efficient and valid method. A review of international studies using traffic observation was done finding 51 publications with a total of 117 observation studies with more than 1,800,000 single observations at more than 17,500 sites from nine different countries. The review describes the relevant aspects of the observation methods and gives an overview about the trends found in the data. As the methods differ widely over the years as well as between the countries and studies, an integration of the results is not possible. However, from all studies it is very clear that smartphone use has increased including not only phoning while driving but also, more important to traffic safety, using apps and texting on the smartphone. Additional observable secondary tasks were only rarely examined. Thus, further research using observational studies is strongly recommended. Suggestions are given with regard to the methodology which can contribute to get comparable and valid results across countries and studies. [ABSTRACT FROM AUTHOR]

Cooperative Intelligent Transport Systems (C-ITS) - Connected Vehicle technology in the USA - where vehicle and roadside infrastructure communicates to deliver more intelligent traffic management, is one of a range of ITS technologies emerging as a key component in pursuit of the wider objectives of improved urban mobility. This paper presents the Compass4D project, which deployed a C-ITS system in seven European cities and coordinated the common evaluation of the technology for three services focusing specifically on safety and environmental objectives under real-world driving conditions. The significance of the Compass4D deployments and results provides some of the first evidence of the effectiveness of C-ITS in real world conditions. Both light and heavy vehicles showed efficiency savings of 2–6%. Equipped buses exhibited a variety of results with one pilot site showing a reduction of greater than 200gCO 2 per bus route per trip whilst other buses showed an increase in total emissions. The paper presents results from both field trials and microscopic simulation studies (to understand the network- or city-wide impacts of the technology). It discusses the results in detail before outlining the potential for further deployment in terms of the impact on energy efficiency and environmental objectives. Government and road operators will benefit from the results to gain an understanding of the potential impact of services given specific deployment characteristics. [ABSTRACT FROM AUTHOR]

In the context of road safety, improvements in road traffic education have been recognized in several countries as an instrument for reducing road accidents. However, the level of road safety education imparted by different institutions lacks an objective performance measure regarding the level of awareness that different participants in the transport process have concerning road transportation risks. Based on an analytical hierarchy process to weigh the relative importance of different questions, in this paper, the fundamentals of a road safety questionnaire are presented and discussed, including the corresponding references for the contents of each question. This test was designed for six road transport participants: car drivers and passengers; public bus, motorcycle and bicycle riders; and pedestrians. For each of these participants, six areas of knowledge were addressed: applied situations, courtesy and urbanity, infrastructure, safety and human factors, traffic signals and rules/recommendations. The target population for applying the test was the inhabitants of the City of Santiago de Queretaro, Mexico. For a grading scale of 1 to 10, the lowest and highest grades were obtained by motorcycle riders (5.72) and pedestrians (8.84), respectively, which denotes the need for better instructions for motorcyclists regarding road safety. [ABSTRACT FROM AUTHOR]

Mobile systems applied to traffic management and control and traffic safety have the potential to shape the future of road transportation. The following innovations, that will be deployed on a large scale, could reshape road traffic management practices: – the implementation of connected vehicles with global navigation satellite (GNSS) system receivers; – the autonomous car revolution; – the spreading of smartphone-based systems and the development of Mobile Cooperative Web 2.0 which is laying the base for future development of systems that will also incorporate connected and autonomous vehicles; – an increasing need for sustainability of transportation in terms of energy efficiency, traffic safety and environmental issues. This paper intends to provide a state of the art on current systems and an anticipation of how mobile systems applied to traffic management and safety could lead to a completely new transportation system in which safety and congestion issues are finally properly addressed. [ABSTRACT FROM AUTHOR]

Introduction: Road traffic injuries are the fifth leading cause of years of life lost, with pedestrians comprising 39% of all road deaths (Global Burden of Disease Mortality and Causes of Death Collaborators [1]). Programs that use injury surveillance data to identify high-risk targets for intervention are known to be effective for reducing injury. This study aims to identify trends in the population incidence of pedestrian traffic injury (PTI) in Victoria, Australia.Method: A retrospective review of data from the Victorian Emergency Minimum Dataset, the Victorian Admitted Episodes Dataset, the Victorian State Trauma Registry and the National Coronial Information System was conducted of patients with a PTI who present to a public hospital emergency department, were admitted to hospital, sustained major trauma or who died of their injuries from January 1st 2009 to December 31st 2013. The primary outcome measure was population incidence of pedestrian traffic-related emergency presentations, hospital admissions, major trauma and deaths.Results: Over the study period, 1838 cases presented to a public hospital emergency department and were discharged without admission to hospital and an additional 3241 cases were admitted to hospital. Of these, 628 cases were classified as major trauma including 90 in-hospital deaths. From January 1st 2008 to December 31st 2011, a total of 216 deaths occurred. A decrease in the population incidence of emergency presentations for PTI was observed over the study period. No significant change was observed in the population incidence of hospital admissions, major trauma cases or deaths from PTI. The demographics of PTI were observed more commonly to be young, intoxicated males and pedestrians aged over 65 years.Conclusions: Although the population-adjusted incidence of emergency presentations for PTI in Victoria has decreased from 2009 to 2013, no change was observed in the incidence of hospital admissions, major trauma or pedestrian fatalities. Novel programs designed to address high-risk groups should be considered to achieve further reductions in PTI and severity of injuries. [ABSTRACT FROM AUTHOR]

This study uses repeated cross-sections of individual level crash data to study the effectiveness of motorcycle helmet legislation. Results suggest that motorcycle helmet laws reduce average individual fatality risks by 20.5%. From a policy standpoint, large states such as Florida and Texas can reduce annual motorcycle fatalities by an average 100 deaths through reinstating universal helmet laws. Valuing these fatality reductions at the U.S. DOT suggested $9.4 million value of a statistical life yields aggregate annual state benefits of approximately $940 million. The effectiveness of helmet legislation can be attributed to the technological efficacy of helmets as well as enhancing behavior in the form of reduced risk taking among motorcyclists. Specifically, motorcyclists who use helmets in order to comply with mandatory helmet laws are 29.8% less likely to receive a traffic citation for risky driving behavior (speeding, alcohol, etc.), travel at a 6 mph lower average speed, and have a 47.4% reduction in the probability of “severely” damaging their motorcycle in a crash. [ABSTRACT FROM AUTHOR]

Background Despite the importance of cycling speed on shared paths to the amenity and safety of users, few studies have systematically measured it, nor examined circumstances surrounding it. Methods Speed was measured for 5421 riders who were observed cycling on shared paths across 12 metropolitan and regional locations in Sydney, Australia. Multivariate regression analysis was carried out to examine rider and environmental factors that contribute to riders cycling above the median speed. Results The study found that observed riders travelled at a median speed of 16 km/h (mean 18.4 km/h). Nearly 80% of riders travelled at 20 km/h or less and 7.8% at speeds of more than 30 km/h. Riders were significantly less likely to cycle above the median speed on shared paths that had an average volume of over 20 pedestrians/hour. Riders were significantly more likely to travel above the median speed on paths that had a centreline (OR: 1.71, 95% CI: 1.41–2.07), on wider paths (over 3.5 m) (OR: 1.34, 95% CI: 1.12–1.59) and on paths with visual segregation between cyclists and pedestrians. Visual segregation, where cycling and walking areas are differentiated by the type of material or by paint colour used, was the strongest predictor of travelling above median speed on shared paths (OR: 3.9, 95% CI: 3.1–4.8). Conclusions The findings suggest that riders adjust their speeds to accommodate pedestrians and path conditions. Path characteristics that support separation from pedestrians may allow relatively higher speeds, and associated amenity, without substantial loss of safety. [ABSTRACT FROM AUTHOR]

Using 2014 and 2015 data from the UK Near Miss Project, this paper examines the stability of self-report incident rates for cycling near misses across these two years. It further examines the stability of the individual-level predictors of experiencing a near miss, including what influences the scariness of an incident. The paper uses three questions asked for only in 2015, which allow further exploration of factors shaping near miss rates and impacts of incidents. Firstly, a respondent's level of cycling experience; secondly, whether an incident was perceived as deliberate; and finally, whether the respondent themselves described the incident as a ‘near miss' (as opposed to only a frightening and/or annoying non-injury incident). Using this data, we find a decline of almost a third in incident rates in 2015 compared to 2014, which we believe is likely to be largely an artefact due to differences in reporting rates. This suggests caution about interpreting small fluctuations in subjectively reported near miss rates. However, in both years near miss rates are many times more frequent than injury collisions. In both years of data collection our findings are very similar in terms of the patterning of incident types, and how frightening different incident categories are, which increases confidence in these findings. We find that new cyclists experience very high incident rates compared to other cyclists, and test a conceptual model explaining how perceived deliberateness, near-miss status, and scariness are connected. For example, incidents that are perceived to be deliberate are more likely to be experienced as very frightening, independent of their ‘near miss’ status. [ABSTRACT FROM AUTHOR]

In order to explore the influence of electric vehicles on the traffic flow characteristics of traditional fuel vehicles, this paper proposes an improved cellular automata model considering the physical properties of vehicles, such as, the acceleration and deceleration amplitude, relative speed and safety distance etc. Based on the sensitivity analysis of the randomization probability, combined with the actual data, the model parameters are quantified to simulate the electric-fuel vehicle mixed traffic flow. Through numerical simulation, the results show that compared with NS (Nagel–Schreckenberg) model and VE(Velocity Effect) model, the improved model can reproduce rich traffic phenomena and is closer to the measured data. With the increase of electric vehicle permeability, the flow rate and speed are increased, the congestion near the critical density is reduced and the traffic safety is improved. At high density, the congestion shows a trend of decreasing first, then increasing and then decreasing again, and the safety is lower than that of homogeneous traffic flow. The speed fluctuation of fuel vehicles is enlarged, and the speed of the overall traffic flow shows an upward trend. In addition, it is found that the TIT curve can identify the state change of traffic flow, and electric vehicles in high-density mixed flow cause greater disturbance to the speed of traffic flow and reduces traffic safety. The results of this paper can provide a basis for further research of electric-fuel vehicle hybrid traffic flow. • A heterogeneous traffic flow model mixed with EVs considering the amplitude of acceleration and deceleration is proposed. • Under medium and high density, the greater the penetration rate of EVs, the greater the vehicle speed and flow rate. • Near the critical density, the threshold of congestion occured increases with the proportion of electric vehicles. • The speed fluctuation of EVs decreases with the increase of its permeability, while fuel vehicles is the opposite. [ABSTRACT FROM AUTHOR]

Accidents between right-turning motor vehicles and straight-ahead cyclists are one of the most common accident types leading to cyclist injuries at signalised junctions in Denmark. A before-after safety evaluation of applying staggered stop lines in 189 arms at 123 signalised junctions is presented. The evaluation accounts for long-term accident trends and changes in motor vehicle traffic volumes. Applying staggered stop lines gives no decline in accidents between right-turning motor vehicles and straight-ahead cyclists. However, there is a statistical tendency to a decline of these right-turn accidents involving heavy vehicles. There are several questions about factors leading to right-turn accidents that cannot be answered by recorded accident data. A study of conflicting behaviour focuses on factors leading to conflicts. Video observations have been carried out in 10 arms at signalised junctions. A total of 45 situations with conflicting behaviour between right-turning motor vehicles and straight-ahead cyclists have been investigated and compared to a reference group of simultaneous arrivals. The relative risk is lowest when both parties stop on red before entering the junction. Upon simultaneous arrival of both parties at a green light, the relative risk is highest. Cyclists tend to have a higher relative risk of being involved in conflicts if they; a) ride through on yellow, b) have a time distance of at least 2 seconds to other cyclists, c) wear a black jacket, and/or d) arrive at the junction at a speed of at least 25 km/h. Much less can be said about the motor vehicles or their drivers on the basis of these video observations, but motor vehicles stopping in the cycle crossing in order to yield to pedestrians or cyclists have a higher relative risk of being involved in conflicts. [ABSTRACT FROM AUTHOR]

The computer simulation of fire spread based on modelling of complex processes related to fire by Computer Fluid Dynamics CFD theory should be a significant contribution to increase of safety of road tunnels. This paper is about instant project aimed at creating simulation models of formation and spread of fires in the road tunnel. The simulations will be compared with real in-situ measurements of fire scenarios suggested by customer organization in two road tunnels. Within the project, Tunnel Traffic and Operation Simulator, as unique facility at University of Žilina will be extended by visualizations of smoke stratification in the virtual tunnel tube. [ABSTRACT FROM AUTHOR]

The paper presents essence of traffic risk. Determinants of this derivative of frequency and consequences are enumerated and described. The main attention is focused on kind of consequences, type of vehicle, injury seriousness as well as kind of accident participant. Basing on classical risk approach, traffic risk assessment methodology is created. It plays a crucial role in formulating risk strategies, implemented from most popular, international risk management standards – PRINCE2® and PMI®. Recommendations for traffic safety improvement base on an unique comparison of risk assessment results and general risk strategies, and they are implemented into real data that characterizes the biggest city in Poland – Warsaw. [ABSTRACT FROM AUTHOR]

This paper reviews the preconditions for successful applications of Experimental Economics methods to research on transportation problems, as new transportation and research technologies emerge. We argue that the application of properly designed incentives, the hallmark of Experimental Economics, provides a high degree of experimental control, leading to internal validity and incentive compatibility. Both of these are essential for ensuring that findings generalize to contexts outside the immediate application. New technologies, such as virtual reality simulators, can generate external validity for the experiments by providing realistic contexts. GPS and other tracking technologies, as well as smart phones, smart cards and connected vehicle technologies can allow detailed observations on actions and real-time interactions with drivers in field experiments. Proper application of these new technologies in research requires an understanding of how to maintain a high level of internal validity and incentive compatibility as external validity is increased. In this review of past applications of Experimental Economics to transportation we focus on their success in achieving external and internal validity. [ABSTRACT FROM AUTHOR]

• The study explored the difference in mobile phone use while driving across the time of day. • The impact of roadway design, traffic operation, and traffic control were different across morning, evening, and off-peak, investigated by structural equation modeling (SEM) in a naturalistic and big data environment. • High roadway design level increased the participation of mobile phone use while driving in the morning peak. • Strong traffic control encouraged drivers to engage in mobile phone use while driving. Mobile phone distracted driving (MPDD) is one of the most significant and common factors in distraction-affected crashes. In previous studies, MPDD has been described as a self-selected behavior that affects driving performance, rather than a multidimensionally impacted behavior. In this study, the researchers hypothesized that external environmental features significantly impacted MPDD and tested this hypothesis by structural equation modeling (SEM). Three external latent variables (road, operation, and control factors) were measured at different times during weekdays in urban areas of Texas by integrating a large number of mobile phone sensor data and roadway inventory data. A structural model was developed to test the relationship between the latent variables and the rate of drivers involved in MPDD (MPDDR) on the roadway during different time periods. Finally, the data summary and model results revealed significant temporal effects. Standardized estimates from the SEM results revealed the positive impact of roads factors in the morning peak that broader shoulders, wider medians, and smaller curve radians were correlated with higher MPDDR in the morning peak hours; the negative impact of operation factors that higher average annual daily truck traffic (truck AADT) were associated with lower MPDDR significantly. And the impact of control factors on MPDDR is positive. In other words, the road segments with a large number of traffic signals in urban areas had a higher MPDDR than those without traffic signals. These findings could assist transportation and legislation agencies in the development of appropriate countermeasures or enforcement tactics and implement them effectively to reduce the occurrence of MPDD. In addition, this study provides a novel perspective close to the actual consideration of drivers about using mobile phones while driving, in the context of MPDD research, rather than comparing driver groups and vehicle performance. [ABSTRACT FROM AUTHOR]

The pedestrian safety can be evaluated by proactive methods (conflict techniques). Proactive method is a cost-effective technique as compared to the historic crash data analysis. Pedestrian safety studies at mid-block crosswalks based on proactive methods are required due to the growing number of pedestrian crossing facilities in developing countries. Hence, the present study evaluated the pedestrian safety at unprotected mid-block crosswalks by considering the proactive safety measure as a pedestrian safety margin (PSM). PSM is the time difference between accepted vehicular time gap with reference to the pedestrian crossing path and pedestrian actual crossing time (based on the field conditions). To fulfill this objective eight unprotected mid-block crosswalks were selected which have different roadway characteristics. Video graphic survey has been conducted for data collection at these locations. PSM values were extracted corresponding to the pedestrian behavioural, vehicular and traffic characteristics at all the eight crosswalks. Further, stepwise regression and binary logit models (the probability of pedestrian-vehicle non-conflict) have been developed in order to find out the factors contributing to the PSM values as well as predicting the probability of avoiding conflict with an approaching vehicle at unprotected mid-block crosswalks. From the study, it is observed that pedestrian behavioural characteristics such as rolling behaviour and speed change conditions significantly reduce the PSM values, and it influences the probability of avoiding conflict with an approaching vehicle at unprotected mid-block crosswalks. These findings may be useful for evaluation of the existing unprotected mid-block crosswalk locations and for increasing the pedestrian safety at these crosswalks by considering suitable control measurements on pedestrian behaviour under mixed traffic conditions. [ABSTRACT FROM AUTHOR]

Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, reliability, etc.) and estimated the expected capacity and safety conditions. These latter were studied with the method provided by the Highway Safety Manual (HSM), as well as by undertaking sensitivity analyses to quantify the expected changes in crash frequency at varying HSR activation hours (from 30 to 200 h) in a year. It has been observed that HSR activation does not involve significant variations in the general safety conditions in the presence of a considerable capacity increase up to 35%. Moreover, have been identified the cases which require speed limit implementation (with VSLs system) in function of the values of reliability ϕ and velocity process V ‾ , and also suggested a speed limit sign system. [ABSTRACT FROM AUTHOR]

This paper examines the determinants of road traffic crash fatalities in Queensland for the period 1958–2007 using a state-space time-series model. In particular, we investigate the effects of policies that aimed to reduce drink-driving on traffic fatalities, as well as indicators of the economic environment that may affect exposure to traffic, and hence affect the number of accidents and fatalities. The results show that the introduction of a random breath testing program in 1988 was associated with a 11.3% reduction in traffic fatalities; its expansion in 1998 was associated with a 26.2% reduction in traffic fatalities; and the effect of the “Safe4life” program, which was introduced in 2004, was a 14.3% reduction in traffic fatalities. Reductions in economic activity are also associated with reductions in road fatalities: we estimate that a one percent increase in the unemployment rate is associated with a 0.2% reduction in traffic fatalities. [ABSTRACT FROM AUTHOR]

Growing traffic in China has resulted in a demand for freeway exit ramps with higher capacity in order to avoid congestion. The right single-lane exit ramp is the most common style of the freeway exit ramp which can be divided into two types: taper-type single-lane exit ramp and parallel-type single-lane exit ramp. The main objective of the paper was to elaborate recommendations about the best single-lane exit ramp layout according to different parameters by evaluating safety and capacity. 6 taper-type and 4 parallel-type exit ramps were selected in Jiangsu Province and the space mean speeds ( SMS ) of the 200 vehicles on the deceleration lane of each sample were observed. The average SMS standard deviation of taper-type was 8.0 kmph comparing with 4.6 kmph of parallel-type, which indirectly indicated that parallel-type single-lane exit ramp was safer than the other one. The capacities of the two exit ramp types were analyzed using the FHWA 's Traffic Software Integrated System ( TSIS ). Two microsimulation models were constructed and the vehicle input varied from 0 to system alert “backed up” by each increment of 100 pcph . The capacity was defined as the input value before the system “backed up”. The results of the two exit ramp types were 1800 pcph and 2100 pcph , which meant the capacity of parallel type was more than the taper type. [ABSTRACT FROM AUTHOR]

Recently, the need of pedestrian detection at night has gained more and more interest. However, the performance of traditional nighttime pedestrian detection systems remains poor because region of interest (ROI) generation and feature extraction are designed separately. Thus, this paper presents novel thermal imagery algorithms to enhance the performance of nighttime pedestrian detection systems. The proposed thermal image pedestrian detection system involves novel outline features, developed from the ROI generation method of pedestrians that are different from traditional features. A three-layer back-propagation feed-forward neural network is used as the classifier. Two databases, the OTCBVS database and our own are used to evaluate the performance of the proposed thermal image pedestrian detection algorithm. Experimental results show that the proposed outline features are effective, and the detection performance of a traditional pedestrian detection system at night is improved. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to evaluate the possibility of enhancing the visibility of motorcycles and pedestrians for motorists via safety messages concerning the vulnerability of these road users. Background In several cases of collision between cars and vulnerable road users (VRU), car drivers failed to detect the latter in time to avoid collision because of their low conspicuity. Method 2 groups of 17 motorists (23.6 years old) carried out a VRU detection task in 2 sessions in a car-driving simulator after either watching or not watching a film presenting safety messages about the vulnerability of these road users. Participants had to detect pedestrians and motorcyclists standing at the road side or who appeared on different parts of the road. Results The group of motorists who watched the film detected these VRUs at a greater distance and drove safely in zones which constitute a high risk of collision for pedestrians (key areas). Only the intensity of anger felt after the film can explain the improvement in VRU visibility distance. Moreover, this improvement was also associated with a modification in speed management in key areas. This last result provides evidence of the importance of top down processes in the detection of VRUs by motorists. Conclusion The film enhanced VRU visibility and led to safer driving behaviour for pedestrians. Application The practical implications of these results for safety campaigns and future directions of research on the emotional states of motorists and their perception during driving are considered. Short abstract We examine motorists’ ability to detect motorcycles and pedestrians (VRUs) in a simulated car-driving task after watching a film presenting safety messages about VRU vulnerability. Informed motorists detect VRU sooner and drive in a safer way for pedestrians. We also consider practical implications and futures lines of research related to safety campaigns. [ABSTRACT FROM AUTHOR]

Truck-related crashes contribute to a significant percentage of vehicle crashes in the United States, which often result in injuries and fatalities. The amount of truck miles traveled has increased dramatically with the growing rate of freight movement. Regarding truck crashes in the highway work zones, many studies indicated that there was a significant increase in crash severity when a truck crash occurred in work zones. To mitigate the risk of truck crashes in work zones, a portable changeable message sign (PCMS) was frequently utilized in addition to standard temporary traffic control signs and devices required by the Manual on Uniform Traffic Control Devices. To justify the use of a PCMS in work zones, there is a need to study the effective location of a PCMS deployed in a work zone by measuring the changes of truck and passenger car speed profiles. The difference of speed changes between trucks and passenger cars was considered as one of the major reasons which caused truck-related crashes in work zones. Therefore, reducing the difference of speed changes between trucks and passenger cars could potentially improve safety in work zones. The outcomes of this study will provide required knowledge for traffic engineers to effectively utilize the PCMS in work zones with the purpose of reducing truck-related crashes. In addition, the success of this study will provide a roadmap to investigate the effective deployment of other temporary traffic control devices on mitigating the risk of truck-related crashes in work zones. [ABSTRACT FROM AUTHOR]

The advent of Big Data era has transformed the outlook of numerous fields in science and engineering. The transportation arena also has great expectations of taking the advantage of Big Data enabled by the popularization of Intelligent Transportation Systems (ITS). In this study, the viability of a proactive real-time traffic monitoring strategy evaluating operation and safety simultaneously was explored. The objective is to improve the system performance of urban expressways by reducing congestion and crash risk. In particular, Microwave Vehicle Detection System (MVDS) deployed on an expressway network in Orlando was utilized to achieve the objectives. The system consisting of 275 detectors covers 75 miles of the expressway network, with average spacing less than 1 mile. Comprehensive traffic flow parameters per lane are continuously archived on one-minute interval basis. The scale of the network, dense deployment of detection system, richness of information and continuous collection turn MVDS as the ideal source of Big Data. It was found that congestion on urban expressways was highly localized and time-specific. As expected, the morning and evening peak hours were the most congested time periods. The results of congestion evaluation encouraged real-time safety analysis to unveil the effects of traffic dynamics on crash occurrence. Data mining (random forest) and Bayesian inference techniques were implemented in real-time crash prediction models. The identified effects, both indirect (peak hour, higher volume and lower speed upstream of crash locations) and direct (higher congestion index downstream to crash locations) congestion indicators confirmed the significant impact of congestion on rear-end crash likelihood. As a response, reliability analysis was introduced to determine the appropriate time to trigger safety warnings according to the congestion intensity. Findings of this paper demonstrate the importance to jointly monitor and improve traffic operation and safety. The Big Data generated by the ITS systems is worth further exploration to bring all their full potential for more proactive traffic management. [ABSTRACT FROM AUTHOR]

This paper describes the approach taken and the results to develop guidance, to include Resilience Engineering principles in methodology for safety assessment of functional changes, in Air Traffic Management (ATM). It summarizes the process of deriving resilience principles for ATM, originating from Resilience Engineering concepts and transposed into ATM operations. These principles are the foundation for guidance material incorporating Resilience Engineering (RE) concepts into safety assessment methodology. The guidance material provides a method using workshops generating qualitative descriptions of RE principles applied to ATM services of everyday work, as done currently and as envisioned after introduction of a new technology or way of working. The guidance material has been proposed as part of the safety assessment methodology of SESAR (Single European Sky ATM Research), and as stand-alone guidance for ATM design processes. The methodology was validated via a test case on the i4D/CTA (Controlled Time of Arrival) concept. Operational examples from the application of the developed guidance to the i4D/CTA concept are provided. Initial evaluation of the guidance suggests that the methodology (1) provides a narrative, vocabulary and documentation means of project discussions on resilience; (2) brings the discussions of safety and resilience closer to operational practice; (3) facilitates a broader systemic and integrative perspective on operational, management, business, safety, environmental, and human performance aspects; and (4) can extend the vocabulary of safety assessment to include the description of emergent properties, to better support functional changes in ATM. [ABSTRACT FROM AUTHOR]

Rapid urbanization in many large cities in China makes metro station an integral part of metropolitan people's daily life. High density of crowds in metro stations would cause serious congestion problems and pose threats to pedestrian safety. Because of the heterogeneous and complex properties of pedestrians, traditional approaches face difficulties in predicting future pedestrian flow patterns. The use of agent-based simulation approach makes it possible to naturally reproduce various pedestrian behaviors in different scenarios. This paper presented an agent-based microscopic pedestrian simulation model—CityFlow, which was proved to be flexible in revealing most important pedestrian behaviors in metro stations by several simulation cases. The model applications can provide implications in evaluation of design proposals of metro facilities. [ABSTRACT FROM AUTHOR]

Research has paid little attention to driving and road safety in the ultraorthodox communities in Israel, in which perceptions on such issues display unique cultural characteristics, and may have long-term effects on traffic safety. This study attempts to gain insight into the attitudes and behaviors of the ultraorthodox young men road users in Israel with regard to driving and road safety, using a qualitative research method based on 42 face-to-face in-depth interviews with men from different ultraorthodox circles in different stages of life. The analysis reveals that the stringent cultural norms strongly influence road behavior, far beyond what is known about young novice drivers and their peers in general. For example, owning a license by young, single ultraorthodox students is seen as an offense against the ultraorthodox establishment compared to driving without a license, which is considered a one-time lapse. The findings indicate that unique cultural phenomena such as concealing the process of licensing, unlicensed driving and road interactions create a dangerous effect extending beyond the ultraorthodox neighborhoods. They also imply that road safety can be interpreted differently in diverse cultures, a fact which should be considered while planning safety intervention strategies. [ABSTRACT FROM AUTHOR]

Two-dimensional multi-objective optimizations have been used for decades for the problems in traffic engineering although only few times so far in the optimization of signal timings. While the other engineering and science disciplines have utilized visualization of 3-dimensional Pareto fronts in the optimization studies, we have not seen many of those concepts applied to traffic signal optimization problems. To bridge the gap in the existing knowledge this study presents a methodology where 3-dimensional Pareto Fronts of signal timings, which are expressed through mobility, (surrogate) safety, and environmental factors, are optimized by use of an evolutionary algorithm. The study uses a segment of 5 signalized intersections in West Valley City, Utah, to test signal timings which provide a balance between mobility, safety and environment. In addition, a set of previous developed signal timing scenarios, including some of the Connected Vehicle technologies such as GLOSA, were conducted to evaluate the quality of the 3-dimensional Pareto front solutions. The results show success of 3-dimensinal Pareto fronts moving towards optimality. The resulting signal timing plans do not show large differences between themselves but all improve on the signal timings from the field, significantly. The commonly used optimization of standard single-objective functions shows robust solutions. The new set of Connected Vehicle technologies also shows promising benefits, especially in the area of reducing inter-vehicular friction. The resulting timing plans from two optimization sets (constrained and unconstrained) show that environmental and safe signal timings coincide but somewhat contradict mobility. Further research is needed to apply similar concepts on a variety of networks and traffic conditions before generalizing findings. [ABSTRACT FROM AUTHOR]

Austrian road tunnels within the Trans-European Road Network (TERN) must fulfil the requirements of the Directive 2004/54/EC (European Commission, 2004) not later than April 2019. This regulation has to be applied to all tunnels in the TERN with a length of more than 500 m, whether they are in operation, under construction or at design stage, and aims at ensuring a minimum level of safety for road users. One of the main features of this directive is the requirement for providing an egress possibility to a safe environment every 500 m throughout the whole tunnel. The Arlberg road tunnel has a length of some 15.5 km and is in operation for more than 35 years. It is a single tube tunnel operated with bi-directional traffic, but carries a quite low traffic volume. Hence, the construction of a second tube is not really cost effective. Currently the tunnel is equipped with a transversal ventilation system with remotely controlled smoke extraction dampers providing smoke extraction every 100 m. The maximum distance between egress possibilities to a save environment is some 1500 m. Due to the high costs of a construction of a second tube or a parallel running escape gallery, a novel solution was found. The existing fresh air duct will be used as safe escape way between the existing egress possibilities. This solution has big impacts on the ventilation system and on the requirements for thermal structure protection of the new egress ways, i.e. the fresh air duct. In order to overcome this problem, massive changes in the ventilation design have to be performed, accompanied by the installation of a high-pressure water-mist system for structure protection. [ABSTRACT FROM AUTHOR]

The analysis of a road network could be carried out using different techniques, the most advanced of which for the identification of hazardous sites are based on a statistical tool known as a “Safety Performance Function” (SPF). SPFs are fundamental to procedures in the Highway Safety Manual (HSM) and Safety Analyst, both of which require calibration of the SPFs to local conditions. In the case of infrastructure in which the traffic flow is physically divided, such as motorways, there are two different methods to calibrate an SPF; one is based on a consideration of two directional segments, the other one is based on mono-directional segments with a correction factor that takes into account the presence of two directional traffic, as proposed by Safety Analyst. In the first case, traffic flows are the sum of traffic flows for each direction. The two methods give a different calibration factor for local condition, i.e., different performance in terms of goodness of fit and SPF transferability. This paper seeks to address these differences by investigating the two approaches to estimate crash count using a motorway sample data from Italy and focusing on a comparison in terms of model transferability. Furthermore two different SPFs were calibrated on the same data using the two different functional equation form, to evaluate the goodness of fit of the two different traffic based segmentation. The goodness of fit of the models is investigated using CURE plots and the R 2 values. The four sets of models give good results in terms of goodness of fit but they have different values for the calibration factor. The calibration factor of the calibrated mono-directional model is closer to a value of one, suggesting a better goodness of fit on the contrary the HSM model gives the better performance in terms of transfer ability where crash data are not available. [ABSTRACT FROM AUTHOR]

Portable changeable message signs (PCMSs) have been employed in highway work zones as a temporary traffic control device for decades in the United States. Results of previous research showed that the traditional text-based PCMS had several limitations, such as having a short range of legibility and being difficult to read by elderly and non-English-speaking drivers. A few simulation studies indicated that using graphic-aided PCMSs could likely overcome these limitations. This paper presents the results of field experiments that were conducted to determine the effectiveness of graphic-aided PCMS in reducing vehicle speeds in the upstream of highway work zones. In field experiment Phase I, a full-matrix PCMS was programmed to display a work zone graphic and a flagger graphic, which were similar to the W21-1 sign and W20-7 sign, respectively, specified by the Manual on Uniform Traffic Control Devices. In field experiment Phase II, the PCMS was programmed to display two alternative work zone graphics along with the original work zone graphic. 1115 and 1600 valid vehicle speed data were collected during field experiments Phase I and Phase II, respectively. The results of data analysis suggested that graphic-aided PCMSs reduced mean vehicle speeds between 13% and 17% in the upstream of a work zone. This study provided valuable knowledge to government agencies and the transportation industry on how to regulate and implement graphic-aided PCMS in highway work zones. [ABSTRACT FROM AUTHOR]

Highlights: [•] We model non-motorist fatality rates for all 50 states from 1999 to 2009. [•] We examine regulatory influences on non-motorist fatality rates. [•] Fatalities decrease with higher state highway and traffic safety enforcement expenditures. [•] Fatalities increase with higher per capita alcohol consumption. [•] Other tested traffic safety regulations do not impact non-motorist fatalities. [ABSTRACT FROM AUTHOR]

Highlights: [•] CRFs are calculated to determine the reduction of crash index (crashes/mile) and injury severity levels of each group. [•] When the deceleration lane lengths are less than 400ft, the crash frequency decreases with the increment of the distance. [•] When the deceleration lanes are longer than 700ft, the crash frequency increases with the increment of the length. [•] For the one-lane exit, the minimum deceleration lengths are 500ft for the design speed of 55mph, and 700ft for 70mph. [ABSTRACT FROM AUTHOR]

Abstract: Romania is increasing and modernizing its highway network to manage the new transportation system as a result of the development of its economy. It is consequently important that the roads system should be efficiently responsible to the standard traffic requirements. Every safety barrier producer must have an investigation report, known as crash-test. Protective guardrails have as most important aim the redirection of the vehicles on the roadway, ensuring directing pedestrians and other road users. Safety barriers are situated on hazardous road sections in terms of traffic security, to keep vehicles on roadway. Crash-tests are quite expensive and given that they have need of specialized services and qualified personnel, the result is that important decisions are quite often based on the results of a few full-scale impact tests. At present, worldwide, protective guard rails are manufactured in different geometric configurations, depending on different fixing modes in soil, in order to enlarge impact strength capacity for different types of collisions. In this paper, the authors propose and analyze the impact behavior of two new safety guardrail systems in order to raise the impact energy absorption. The tests were performed using as impact or a 1500kg Chevrolet C1500 pick-up truck from the NCAC models library. [Copyright &y& Elsevier]

Highlights: [•] Our study recommends not considering the DIC as the sole model selection criterion. [•] Comparison should be done between the models that have similar parameterization. [•] The study also recommends considering other alternatives in addition to the DIC. [ABSTRACT FROM AUTHOR]

• Factors affecting motorcycle crash casualty severities at intersections are explored. • The analysis is performed using the association rules mining algorithm. • Chains of factors influencing severity outcomes differ by type of intersection. • Nighttime and no shoulders are related with fatalities at unsignalized intersections. • Daylight and road shoulder are associated with fatalities at signalized intersections. Despite the countless benefits derived from motorcycle usage, it has become a significant public health concern, particularly in developing countries, due to the plateauing number of fatal/serious injuries associated with them. Although it has been well documented that the frequency and fatality rates of intersection-related motorcycle crashes are high, little research efforts have been made to explore the contributory factors influencing motorcycle-involved crashes at these locations. Interestingly, no study has investigated the latent patterns and chains of factors that simultaneously contribute to the injury severity sustained by motorcycle crash casualties at intersections under different traffic control conditions in developing countries. Since motorcycles are mostly used as taxis in developing countries, it is imperative to consider the injury severity sustained by all crash casualties in the motorcycle safety analysis. This study bridges the research gap by employing a plausible data mining tool to explore hidden rules associated with motorcycle crash casualty injury severity outcomes at both signalized and non-signalized intersections in Ghana's most densely populated region, Accra, using three-year crash data spanning 2016–2018. Besides, a binary logit regression model was also employed to explore the impact of crash factors on casualty severity outcomes using the same dataset. The results from both analysis techniques were consistent; however, the data mining technique provided chains of factors which provided additional insights into the groups of factors that collectively influence the casualty injury severity outcomes. From the rule discovery results, while full license status, daytime/daylight, and shoulder presence increased the risk of fatal injuries at signalized intersections, factors such as inattentiveness, good road surface, nighttime, shoulder absence, and young rider were highly likely to increase casualty fatalities at non-signalized intersections. By controlling all or some of these risk factors, the level of injury severity on the roadways could be reduced. Based on the findings, we provide enforcement, education, and engineering-based recommendations to help improve motorcycle safety. [ABSTRACT FROM AUTHOR]

Abstract: One way to improve safety of signalized arterials is to optimize signal timings. Historically, signal retiming tools were used to reduce traffic delay and stops and other measures of traffic efficiency. The concept of optimizing signal timings specifically to improve safety metrics, or their surrogate measures, is not common in current signal timing optimization practice. This study advocates a fresh approach to integrating VISSIM microsimulation software, Surrogate Safety Assessment Model, and VISSIM-based Genetic Algorithm for Optimization of Signal Timings to reduce surrogate measures of safety and thereby reduce risks of potential real-world crashes. In addition, a multiple-objective genetic algorithm is implemented to identify the optimal compromise between two competing objectives: surrogate safety and traffic efficiency. A 12-intersection corridor on Glades Road in Boca Raton and two smaller synthetic network served as case studies. Optimized signal timings delivered a solution that balanced both safety and efficiency. When compared to initial signal timings the estimated number of conflicts was reduced by 7%. In addition, when compared to signal timings optimized for efficiency the estimated number of conflicts was reduced by 9% without a significant loss of efficiency (∼1%). The study also approximated a Pareto Front of conflicts and throughput which may be instrumental when trading off (surrogate) safety for efficiency in the development of signal timing plans. Most of the improvements came at the expense of worsening efficiency of traffic streams which shows an inevitable necessity for trade-off between efficiency and safety. A strong relationship between increase in cycle length and reduction of vehicular conflicts has been observed. Further investigation is needed to validate the approach and perform detailed analysis of impacts of signal timings on vehicular conflicts. [Copyright &y& Elsevier]

Abstract: This paper reviews road safety performance in the United States. The paper develops a framework for assessing dimensions of road safety, and analyzes the importance of economic factors, travel patterns, demographics, road/traffic/vehicle technology, driver behavior, and public policy. Issues and challenges for future road safety research are discussed. [Copyright &y& Elsevier]

Highlights: [•] This paper develops methods to evaluate highway alternative alignments. [•] The methods allow quick and precise reviews of highway alternatives in terms of: [•] Vehicular fuel consumption, sight distance deficiency, and highway safety. [ABSTRACT FROM AUTHOR]

Abstract: A two-pronged effort to quantify the impact of lighting on traffic safety is presented. In the statistical approach, the effects of lighting on crash frequency for different intersection types in Minnesota were assessed using count regression models. The models included many geometric and traffic control variables to estimate the association between lighting and nighttime and daytime crashes and the resulting night-to-day crash ratios. Overall, the presence of roadway intersection lighting was found to be associated with an approximately 12% lower night-to-day crash ratio than unlighted intersections. In the parallel analytical approach, visual performance analyses based on roadway intersection lighting practices in Minnesota were made for the same intersection types investigated in the statistical approach. The results of both approaches were convergent, suggesting that visual performance improvements from roadway lighting could serve as input for predicting improvements in crash frequency. A provisional transfer function allows transportation engineers to evaluate alternative lighting systems in the design phase so selections based on expected benefits and costs can be made. [Copyright &y& Elsevier]

Abstract: The objective of this paper is to develop crash estimation models at traffic analysis zone (TAZ) level as a function of land use characteristics. Crash data and land use data for the City of Charlotte, Mecklenburg County, North Carolina were used to illustrate the development of TAZ level crash estimation models. Negative binomial count models (with log-link) were developed as data was observed to be over-dispersed. Demographic/socio-economic characteristics such as population, the number of household units and employment, traffic indicators such as trip productions and attractions, and, on-network characteristics such as center-lane miles by speed limit were observed to be correlated to land use characteristics, and, hence were not considered in the development of TAZ level crash estimation models. Urban residential commercial, rural district and mixed use district land use variables were observed to be correlated to other land use variables and were also not considered in the development of the models. Results obtained indicate that land use characteristics such as mixed use development, urban residential, single-family residential, multi-family residential, business and, office district are strongly associated and play a statistically significant role in estimating TAZ level crashes. The coefficient for single-family residential area was observed to be negative, indicating a decrease in the number of crashes with an increase in single-family residential area. Models were also developed to estimate these crashes by severity (injury and property damage only crashes). The outcomes can be used in safety conscious planning, land use decisions, long range transportation plans, and, to proactively apply safety treatments in high risk TAZs. [Copyright &y& Elsevier]

Abstract: Previous research has indicated that older drivers are more likely to be involved in collisions in complex traffic scenarios like intersections even if they are not more involved in accidents in general. Moreover, being more vulnerable, the older driver is generally at higher risk of sustaining an injury when involved in a traffic accident. Even though there may be many factors leading to the over-involvement of older drivers in intersection collisions it is clear that the visual capacity and the ability to observe may be one of the possible causes that is of high interest to understand further. The objective of the study is to identify to what degree the visual behaviour could explain older drivers’ involvement in intersection accidents. A 20km long route composed by intersections in rural and urban environment was selected to collect both driving and eye movement data. Two groups of drivers were compared, one group aged 35–55years and one aged 75 and above. Apart from the driving data, neck flexibility measurement was performed. The results from the neck flexibility measurement showed a clear age effect, with the older drivers showing less neck flexibility. When it comes to visual behaviour data, a difference was also found concerning the area of interest the drivers looked at; while the older drivers looked more at lines and markings on the road to position themselves in the traffic, the younger drivers looked more at dynamic objects such as other cars representing a possible threat. The difference in the visual behaviour should be used to design safety systems for all drivers to support them when they drive through an intersection. [Copyright &y& Elsevier]

Abstract: We study the dynamic process of the multiple-vehicle collision when a vehicle stops suddenly in a traffic flow. We apply the optimal-velocity model to the vehicular motion. If a vehicle does not decelerate successfully, it crashes into the vehicle ahead with a residual speed. The collision criterion is presented by if where and are the speed and headway of vehicle i at time t. The number of crumpled vehicles depends on the initial velocity, the sensitivity, and the initial headway. We derive the region map (or phase diagram) for the multiple-vehicle collision. [Copyright &y& Elsevier]

Abstract: This paper investigates fatal accidents and fatalities at level crossings in Great Britain over the 64-year period 1946–2009. The numbers of fatal accidents and fatalities per year fell by about 65% in the first half of that period, but since then have remained more or less constant at about 11 fatal accidents and 12 fatalities per year. At the same time other types of railway fatalities have fallen, so level crossings represent a growing proportion of the total. Nevertheless, Britain''s level crossing safety performance remains good by international standards. The paper classifies level crossings into three types: railway-controlled, automatic, and passive. The safety performance of the three types of crossings has been very different. Railway-controlled crossings are the best-performing crossing type, with falling fatal accident rates. Automatic crossings have higher accident rates per crossing than railway controlled or passive crossings, and the accident rates have not decreased. Passive crossings are by far the most numerous, but many have low usage by road users. Their fatal accident rate has remained remarkably constant over the whole period at about 0.9 fatal accidents per 1000 crossings per year. A principal reason why fatal accidents and fatalities have not fallen in the second half of the period as they did in the first half is the increase in the number of automatic crossings, replacing the safer railway controlled crossings on some public roads. However, it does not follow that this replacement was a mistake, because automatic crossings have advantages over controlled crossings in reducing delays to road users and in not needing staff. Based on the trends for each type of crossing and for pedestrian and non-pedestrian accidents separately, in 2009 a mean of about 5% of fatal accidents were at railway controlled crossings, 52% were at automatic crossings, and 43% were at passive crossings. Fatalities had similar proportions. About 60% of fatalities were to pedestrians. A simple comparison of automatic railway level crossings and signalised road intersections found that in 2005 the numbers of fatalities per 1000 crossings or intersections were similar. [Copyright &y& Elsevier]

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

Abstract: The aim of this paper is to take a holistic perspective to explore levels of cycling and opportunities and barriers to increase children’s safer cycling in disadvantaged areas in England. The study was one part of a larger study which explored the factors underlying the high level of road traffic casualties especially among children in the most disadvantaged areas of England and to explore how this impacts on mobility and quality of life. The methods involved a cross sectional survey comprising school based questionnaire surveys with children aged 9–14 and focus groups with parents who had children within this age range. The surveys were conducted in 2007 and the focus groups during 2008. 4286 children completed the survey and eight focus groups were held. Bike ownership (77%) was high, use in previous week moderate (39%) but only 2% cycled to school. Ownership was significantly lower in minority ethnic groups. Despite young children’s strong preference to travel by cycle (30%) than walk or go by car, most parents felt it was too hazardous. It is unlikely that these findings would be any different from the rest of England, however the combination of environmental and social factors may elevate the risks for young cyclists in these areas. This paper concludes that a number of barriers exist to increasing levels of cycling among children living in disadvantaged areas particularly amongst ethnic groups. These barriers could be addressed by environmental modifications to reduce speeds and by reducing the levels of antisocial driving and riding in residential areas and around destinations where children travel, by providing cycle training to improve children’s skills and parent’s confidence, and by providing secure storage facilities for bikes. Until these barriers are addressed it is unlikely that cycling will increase despite the strong preferences children have to travel by bike. Such preferences to cycle provide an opportunity for local authorities to act on. [Copyright &y& Elsevier]

Abstract: Fault tree analysis (FTA) is a logically structured process that can help identify potential causes of system failure before the failures actually occur. However, FTA often suffers from a lack of enough probabilistic basic events to check the consistency of the logic relationship among all events through linkage with gates. Sometimes, even logic relationship among all events is difficult to determine, and failures in system operation may have been experienced rarely or not at all. In order to address the limitations, this paper proposes a novel incident tree methodology that characterizes the information flow in a system instead of logical relationship, and the amount of information of a fuzzy incident instead of probability of an event. From probability statistics to fuzzy information quantities of basic incidents and accident, we propose an incident tree model and incident tree analysis (ITA) method for identification of uncertain, random, complex, possible and variable characteristic of accident occurrence in quantified risk assessment. In our research, a much detailed example for demonstrating how to create an incident tree model has been conducted by an in-depth analysis of traffic accident causation. The case study of vehicle-leaving-roadway accident with ITA illustrates that the proposed methodology may not only capture the essential information transformations of accident that occur in system operation, but also determine the various combinations of hardware faults, software failures and human errors that could result in the occurrence of specified undesired incident at the system level even accident. [ABSTRACT FROM AUTHOR]

Abstract: Because of rapid increase in the urban population and hence road traffic, the vehicle–pedestrian crashes are more frequent and have become a major concern in road traffic safety. Though the bumper of a vehicle plays an important role to protect the vehicle body damage in low speed impacts, many bumpers particularly in larger vehicles are too stiff for pedestrian protection and safety. To prevent lower extremity injuries in car–pedestrian collisions, it is important to determine the loadings that car front structures impart on the lower extremities and the mechanisms by which injuries are caused. In the present work, a dynamic legform impactor model is introduced and validated against EEVC/WG17 criteria. The collision mechanism between a GMT bumper and the legform impactor model is investigated numerically using LS-DYNA software. The effect of the height of the impact point of bumper assembly to lower extremity injuries is also investigated. In this paper, it is shown that changing the local stiffness of bumper assembly due to the change in the height of the bumper and distribution of stiffness from upper parts of the bumper assembly to lower parts are the most important parameters in the pedestrian’s leg injuries. As lower extremity injuries are related to the lower bumper height, developing special legform impactors for different countries with different average person height seems essential in investigating the effect of people’s height on lower extremity injuries. [Copyright &y& Elsevier]

Abstract: A significant percentage of fatal vehicle crashes involve loss of control (LOC). Electronic stability control (ESC) is an active safety system that detects impending LOC and activates counter-measures that help the driver maintain or re-gain control. To assess the effectiveness of ESC in preventing LOC, an empirical study was conducted on a high-fidelity driving simulator. The ESC systems for two vehicles were incorporated into the simulator''s dynamics code which was calibrated to ensure engineering validation. The study utilized three scenarios designed to recreate typical LOC situations, and was designed to assess the effects of ESC presence, vehicle type, scenario, age and gender. A total of 120 research participants completed the study. Results showed a statistically significant reduction in LOC with ESC compared to without ESC (F =52.72, p <0.0001). The study findings of 5% LOC with ESC and 30% without ESC match several epidemiological studies that have analyzed ESC effectiveness on real-world crashes, providing strong support to the use of driving simulation for studying driver behavior. Study conclusions suggest that wide-spread utilization of ESC is likely to reduce traffic fatalities. [Copyright &y& Elsevier]