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Bicycle–motor vehicle (BMV) crashes have been identified as a major type of traffic accident affecting transportation safety. In order to determine the characteristics of BMV crashes in cold region...

Traffic safety for hazardous material (hazmat) transportation has not been studied well at a macro level in recent years. A Bayesian negative binomial conditional autoregressive safety model was us...

The ownership of motorised two wheelers (MTWs) has been on the rise across various countries across the globe. The growth has been especially higher in developing countries which have typical traffic characteristics and higher populations. This steady rise has resulted in increased accident and fatalities. This abrupt increase warranted attention from the researchers to carry out specific studies for MTWs, which have a very different behaviour as compared to cars in terms of physical and dynamic parameters. Moreover, the unique traffic patterns usually found in the developing countries pose an additional challenge to the researchers, since the conventional focus of transportation safety researchers was a homogeneous car-based traffic. Many such studies have been attempted, especially in the recent decades, which have considered various risk factors related to MTW safety. However, the studies have considered different sets of risk factors and have given surprising and even conflicting results. Therefore, a comprehensive review of the diverse studies needs to be carried out which incorporates all the risk factors considered in previous research. This study reviews such research papers which have analysed various risk factors related to safety of MTWs, especially in heterogeneous, non-lane based traffic. Specifically, this paper aims to incorporate results from those studies and highlight the conclusions from state of the art. The paper also discusses about the research gaps that are crucial for MTW safety in mixed traffic conditions. The review will be useful for researchers working in the field of MTW safety and for policy implementation and analysis.

The underreporting of maritime accident data is a major concern in maritime transportation safety analysis. In order to avoid biased effects caused by the underreporting issue, this study aims to p...

The high number of vehicle–pedestrian crashes in the United State has gained increased attention among transportation safety analysts in recent years. Being directly exposed to the collision force makes pedestrians more prone to becoming severely injured when in crash than other road users. Considering the fact that pedestrian-involved crashes is a serious public health problem, the current study’s aim is to investigate the contributing factors associated with injury severity of pedestrian crashes by time-of-week. Separate injury severity models for weekday and weekend crashes were developed, and the overall stability of the model estimates was examined through likelihood ratio tests. For this purpose, random parameter ordered-response models were employed to specify the ordinal nature of injury severity levels and capture the potential unobserved heterogeneity. In addition, Artificial Neural Network (ANN) was used to explore the nonlinear relationship between explanatory variables and severity outcomes. Comparison of the prediction performance demonstrated that optimized ANN provides superior results compared to conventional statistical approaches. A variable impact analysis was then conducted on the optimized ANN to investigate the effects of the explanatory variables on injury severity. The results revealed the factors that are significantly associated with pedestrian fatalities. These findings further provide insights for a better understanding of pedestrian injury severity in weekday vs. weekend crashes through the impact analysis of various explanatory variables.

International audience; Autonomous Vehicles (AVs) promise of a multi-trillion-dollar industry that revolutionizes transportation safety and convenience depends as much on overcoming the psychological barriers to their widespread use as the technological and legal challenges. The first AV-related traffic fatalities have pushed manufacturers and regulators towards decisions about how mature AV technology should be before the cars are rolled out in large numbers. We discuss the psychological factors underlying the question of how safe AVs need to be to compel consumers away from relying on the abilities of human drivers. For consumers, how safe is safe enough? Three preregistered studies (N = 4,566) reveal that the established psychological biases of algorithm aversion and the better-than-average effect leave consumers averse to adopting AVs unless the cars meet extremely potentially unrealistically high safety standards. Moreover, these biases prove stubbornly hard to overcome, and risk substantially delaying the adoption of life-saving autonomous driving technology. We end by proposing that, from a psychological perspective, the emphasis AV advocates have put on safety may be misplaced.

Purpose For the purpose of reducing the incidence of hazardous materials transport accident, eliminating the potential threats and ensuring their safety, aiming at the shortcomings in the process of current hazardous materials transportation management, this paper aims to construct the framework of hazardous materials transportation safety management system under the vehicle-infrastructure connected environment. Design/methodology/approach The system takes the intelligent connected vehicle as the main supporter, integrating GIS, GPS, eye location, GSM, networks and database technology. Findings By analyzing the transportation characteristics of hazardous materials, this system consists of five subsystems, which are vehicle and driver management subsystem, dangerous sources and hazardous materials management subsystem, route analysis and optimization subsystem, early warning and emergency rescue management subsystem, and basic information query subsystem. Originality/value Hazardous materials transportation safety management system includes omnibearing real-time monitoring, timely updating of system database, real-time generation and optimization of emergency rescue route. The system can reduce the transportation cost and improve the ability of accident prevention and emergency rescue of hazardous materials.

A major focus for transportation safety analysts is the development of crash prediction models, a task for which an extremely wide selection of model types is available. Perhaps the most common cra...

The growth of metropolitan regions in the U.S. leads to transportation safety issues related to roadway crashes that imperil personal well-being. Previous studies have investigated the environmenta...

Safety, along with the issue of security, is the most substantial and critical issue to any society and nation of the mankind. The fact that human elements contribute dominantly, in particular, to the transportation – marine, air and road traffic – accidents requires not only the technical approaches, but also cultural configuration inherent to the accidents. This paper tries to incorporate Hofstede’s dimensions of national culture to identify possible interaction with accidents. It will be of help to figure out the need to consider the aspect of national culture to be efficient in dealing with policies for safer communities and nations.

Fatigue that is related to the amount and quality of sleep obtained can impair human performance in ways that can lead to accidents. As many transportation industries operate around the clock, fatigue and its effects cannot be eliminated completely; instead, they must be managed. A first step is to document the prevalence and role of fatigue in accidents that occur. The Transportation Safety Board of Canada (TSB) routinely investigates such transportation industry incidents to determine if fatigue was present, if it played a role, and if there were practices in place to effectively manage it and associated risks. Herein, we summarize and describe the TSB's fatigue investigation methodology in the hopes that investigators of other organizations and domains will find the concepts applicable to their operational context.

Walking and bicycling to school (active school transportation, AST) has been in decline for decades in North America and globally with the rise of automobility. This cross-sectional study estimated associations between the built environment and AST in seven Canadian communities. We observed the travel behaviours of almost 118,000 students at 552 schools. Using beta regression, we modeled the proportion of children using AST, considering built environment and social environment factors around schools. Across all schools, the average proportion of children using AST was 54.3% (SD 18.9%), with variability among cities from a low of 39.5% (SD 22.1%) in Laval, Quebec to 69.7% (SD 18.1%) in Montreal, Quebec. Overall, several modifiable road design features were associated with AST, including the presence of school crossing guards, cycling infrastructure, Walk Score® and traffic signal density. There was variability in the directionality and statistical significance of associations with design variables across cities, suggesting that the local context and directed local interventions are important to support AST. Natural experiment studies are necessary to examine local approaches related to the built environment to increase AST and ensure appropriate new policy and program interventions are developed.

The article presents definitions of and approaches to the concept of safety in order to confirm the subjective character of its determination, description, and interpretation. By presenting examples of security statistics and safety-related behaviours, its ambiguity and complexity are revealed. The author draws attention to the media’s attitude towards safety-related incidents. With reference to contemporary scientific knowledge about the methods of improving safety in transportation organizations, the author also suggests that safety improvement initiatives should focus more strongly on facilitating closer cooperation between leaders, superiors and subordinates with different levels of experience.

How safe are autonomous vehicles? The answer is critical for determining how autonomous vehicles may shape motor vehicle safety and public health, and for developing sound policies to govern their deployment. One proposed way to assess safety is to test drive autonomous vehicles in real traffic, observe their performance, and make statistical comparisons to human driver performance. This approach is logical, but it is practical? In this paper, we calculate the number of miles of driving that would be needed to provide clear statistical evidence of autonomous vehicle safety. Given that current traffic fatalities and injuries are rare events compared to vehicle miles traveled, we show that fully autonomous vehicles would have to be driven hundreds of millions of miles and sometimes hundreds of billions of miles to demonstrate their reliability in terms of fatalities and injuries. Under even aggressive testing assumptions, existing fleets would take tens and sometimes hundreds of years to drive these miles—an impossible proposition if the aim is to demonstrate their performance prior to releasing them on the roads for consumer use. These findings demonstrate that developers of this technology and third-party testers cannot simply drive their way to safety. Instead, they will need to develop innovative methods of demonstrating safety and reliability. And yet, the possibility remains that it will not be possible to establish with certainty the safety of autonomous vehicles. Uncertainty will remain. Therefore, it is imperative that autonomous vehicle regulations are adaptive—designed from the outset to evolve with the technology so that society can better harness the benefits and manage the risks of these rapidly evolving and potentially transformative technologies.

Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become one of the primary tools we use daily both in our personal and professional lives. The applications play key roles in facilitating many applications that are pivotal in our today's society including communication, education, business, entertainment, medical, finance, travel, utilities, social, and transportation. This paper reviewed the opportunities and challenges of the applications related to transportation. The opportunities revealed include route planning, ridesharing/carpooling, traffic safety, parking information, transportation data collection, fuel emissions and consumption, and travel information. The potential users of these applications in the field of transportation include (1) transportation agencies for travel data collection, travel information, ridesharing/carpooling, and traffic safety, (2) engineering students for field data collection such as travel speed, travel time, and vehicle count, and (3) general traveling public for route planning, ridesharing/carpooling, parking, traffic safety, and travel information. Significant usage of smart mobile applications can be potentially very beneficial, particularly in automobile travel mode to reduce travel time, cost, and vehicle emissions. In the end this would make travel safer and living environments greener and healthier. However, road users' interactions with these applications could manually, visually, and cognitively divert their attention from the primary task of driving or walking. Distracted road users expose themselves and others to unsafe behavior than undistracted. Road safety education and awareness programs are vital to discourage the use of applications that stimulate unsafe driving/walking behaviors. Educating the traveling public about the dangers of unsafe driving/walking behavior could have significant safety benefits to all road users. Future research needs to compare accuracies of the applications and provide guidelines for selecting them for certain transportation related applications.

This study aimed at investigating how driver's mental workload could be assessed during driving, using driving performance as well as electrophysiological and subjective data. Participants had to follow a lead vehicle at a safe and constant distance and to deal with two particular driving events (overtaking and pedestrian occurrence) within two sessions (baseline and experimental) on a driving simulator. Traffic density and time pressure (overtaking event) and time pressure (pedestrian event) were increased in the experimental session in order to induce a higher workload. Participants filled NASA TLX questionnaire after each driving session. Electrophysiological parameters (SCL, ECG), driving performance (SDLP and response to speed change of the lead vehicle: coherence, delay and gain) were analysed after each event in two temporal windows (30 sec and 5 min). Results showed that both performance and physiological variables differed as a function of traffic conditions and time pressure. Moreover, while performance variations were systematically observed over a long period (five minutes after the events), effects on mean SCL data obtained from experimental session notably differed from baseline values within thirty seconds after the events. Results are discussed in term of mental workload and suggestions are made about the safety systems that could monitor driver's mental state.

In both developing and advanced economies, it is commonly believed that lower income and minority populations are disproportionately at risk of being injured or killed in a motor vehicle crash, especially as pedestrians. However, this risk is rarely quantified with information about exposure. We argue that a combined transportation–population health framework is one way to quantify, and therefore prioritize, equity considerations in transportation safety decision-making. We illustrate this approach with an analysis that compares age-adjusted fatal and nonfatal injury rates per 100 million person-trips by race/ethnicity and sex for motor vehicle occupants, bicyclists, and pedestrians. We found that, per trip, whites are equally safe as pedestrians and motor vehicle occupants, whereas other racial and ethnic groups for whom we have data are less safe when they walk. In addition, black/African-American female motor vehicle occupants and pedestrians have higher inpatient injury risk than female travel...

During the past few decades, there has been a surge of interest in research seeking to understand how personal and public health are affected by transportation systems. A large and diverse literature has recently emerged as a result, which complements a rich literature developed beginning in the early 20th century. In this manuscript, we identify five unique research trajectories in health and transportation that, in many cases, seem unrelated. After exploring these five areas, we argue that a holistic viewpoint that links all of the ways transportation systems impact health will provide new opportunities for health and transport researchers. To do this, we present a causal loop diagram, which illustrates a systems perspective on the complex relationships between health and transportation. Finally, a discussion on future directions points out ways that such a perspective will benefit researchers going forward.

Introduction: Driver distraction has become a significant problem in transportation safety. As more portable wireless devices and driver assistance and entertainment systems become available to drivers, the sources of distraction are increasing. Method: Based on the results of different studies in the literature review, this paper categorizes different distraction enablers into six subcategories according to their fundamental characteristics and how they would affect a driver's likelihood of engaging in non-driving related activities. The review also discusses the characteristics and influence of external and internal distractions. The objective of this study is to examine the effect of different distraction sources in fatal crashes with the consideration of a driver's age and sex. Tukey test, chi-square test of independence, Nemenyi post-hoc test, and Marascuilo procedure have been used to investigate the top distraction sources, the trend of distraction-affected fatal crashes, the effect of different distractions on drives in different age groups, and their influence on female and male drivers. Results: It was found that inner cognitive inferences accounted for the greatest proportion of driver engagement in distractions. Young drivers show a larger probability of being distracted by in-vehicle technology-related devices/objects. Within the group of young drivers, female drivers showed a higher probability than their male counterparts of engaging in distracted driving caused by in-vehicle technology-related devices. Among six subcategories of distractions, drivers older than 80 years old were found to be most likely affected by inner cognitive interferences.

Obstacles detection systems are essential to obtain a higher safety level on railways. Such systems has the ability to contribute to the development of automated guided trains. Even though some laser equipments have been used to detect obstacles, short detection distance and low accuracy on curve zones make them not the best solution. In this paper, after an assessment of the risks related to railway accidents and their possible causes, computer vision combined with prior knowledge is used to develop an innovative approach. A function to find the starting point of the rails is proposed. After that, bottom-up adaptive windows are created to focus on the region of interest and ignore the background. The whole system can run in real time thanks to its linear complexity. Experimental tests demonstrated that the system performs well in different conditions.

Fatigued driving is a major cause of road accidents. For this reason, the method in this paper is based on the steering wheel angles (SWA) and yaw angles (YA) information under real driving conditions to detect drivers' fatigue levels. It analyzes the operation features of SWA and YA under different fatigue statuses, then calculates the approximate entropy (ApEn) features of a short sliding window on time series. Using the nonlinear feature construction theory of dynamic time series, with the fatigue features as input, designs a "2-6-6-3" multi-level back propagation (BP) Neural Networks classifier to realize the fatigue detection. An approximately 15-h experiment is carried out on a real road, and the data retrieved are segmented and labeled with three fatigue levels after expert evaluation, namely "awake", "drowsy" and "very drowsy". The average accuracy of 88.02% in fatigue identification was achieved in the experiment, endorsing the value of the proposed method for engineering applications.

In the mid-2000s, public transit agencies began testing onboard video feedback systems on buses, which capture short video clips when triggered by an unusual event such as hard braking, a sharp turn, or impact with an object. The objective of this study was to deter mine whether the systems have enhanced passenger safety by reducing the frequency and severity of collisions and injuries and to identify lessons learned from the implementation of such systems. The study concludes that the systems appear to have a positive impact on transit safety achieved through a reduction in collisions and injuries and the risky driving behaviors that contribute to them. The systems provide transit mangers with a wealth of information about their employees’ driving habits that was not previously available. Transit agencies should consider investing in such systems as one component of an overall safety and training program.

This paper analyzes the transportation fatality risk in the United States. The analysis is in two parts. The first part compares the relative risks of the different modes based on data for the decade from 2000 to 2009. The second part is a time-series analysis for each mode using annual data from 1975 to 2010. By almost any measure, transportation is considerably safer now than it was in the mid 1970s. The improvement is especially noticeable for commercial modes such as aviation, railroads and maritime. Even the risks from private highway driving have halved during the past thirty-five years.

One of the primary sources of information and inspiration in the creation of new, more secure solutions in traffic organization are the occurrences with most serious consequences called accidents (air), serious accidents (rail) or catastrophes (road, sea). Accidents investigation is usually conducted in terms of searching for the reasons of these events and to make preventive recommendations aimed at elimination of these causes. In this paper, it is proposed to draw more attention to the events of somewhat less severity of the consequences - serious incidents (air), traffic conflicts (road) and incidents (rail, maritime). A model of real serious traffic incident, created with the use of stochastic, timed Petri nets is presented. Simulation experiments were carried out, which allowed for determination of the probability of transformation of the incident into the accident. The proposed method of analyzing serious traffic incidents also allows to determine the effectiveness of the barriers that have prevented an accident in a real occurrence.

Reliability-based analysis of road geometric design has been reported in literatures as a trend in transportation safety study. In the reliability analysis of a horizontal curve, the performance function is usually formulated as a function of the failure mode of vehicle skidding only. This paper takes into account the failure modes of vehicle skidding and rollover in formulating the performance functions of cars and trucks, respectively. A comparative study of three different performance functions for calculating the probability of vehicle failure modes is conducted. The results qualitatively show that trucks are more vulnerable to skid than cars, and are more likely to rollover than to skid on dry pavement. A vehicle's is greatly influenced by vehicle suspension and roll motion. A sensitivity analysis investigating the influences of vehicle parameters and superelevation on vehicle skidding and rollover follows. In order to make the paper practically useful, the probability of failure for the minimum radius recommended by AASHTO at various superelevations and design speeds was computed to investigate the reliability of the recommended minimum radius.

Purpose Most school bus related injury events in Sweden take place when the child is outside the bus. In order to enhance their safety, the societal costs of four different measures applied on “bus stops” on high speed roads were investigated. Methods From a door-to-door perspective, a measure hierarchy, comprising the four existing measures, viz.: Rerouting using the current operating vehicle, New construction, Rerouting using a different operating vehicle, Speed reduction in the vicinity of the “bus stop” was applied. Results By allocating 7.7 € per child per school day, almost nine out of ten children’s transportation safety may substantially be enhanced, simply by rerouting the current operating vehicle or using alternative operating vehicles. Conclusions In the investigated municipality it was feasible to enhance school transportation safety for children by implementing cheap and alternative measures.

Purpose – The objective of this paper is the development of a voluntary compliance model that is applied to the current and substantive governmental regulatory electronic on‐board recorder (EOBR) proposal in the workplace.Design/methodology/approach – This study is designed to qualitatively evaluate the responses of commercial drivers to the federal government's proposed EOBR safety technology. Results are based on the analysis of published comments made by commercial drivers to a US government online database, the Federal Docket Management System.Findings – Four major thematic categories emerged from the commercial driver comments are analyzed, including government control over workplace behavior; financial impact; technology readiness; and attribution issues –, e.g. misplaced responsibility for safety problems (generally on other drivers or outside parties). This paper links these concerns to a procedural justice model and discusses how procedural justice concerns can contribute to voluntary compliance ...

This paper focuses on the situation in the cold region of China where the transportation safety management of road is passive and negative, the coordination between managements is poor, and the efficiency of emergency rescue is low in snow-icing weather. It also analyzes the characters of road transportation safety in snow-icing weather, and summarizes the national and foreign disposal strategies to deal with snow-icing traffic. Then three effective strategies that can reduce the impact on road transportation safety by snow-icing weather have been received, including the provision of information, traffic control, and dealing with the snow-icing. The paper also discusses the effect of each strategy from the perspective of road maintenance managers, emergency managers, traffic managers, and road users. It will be helpful to improve the operations of road transportation safety in snow-icing weather in the cold region of China. Language: en

With most of the global population and capital goods concentrated in urban areas, cities are key to social development and economic prosperity. They are drivers of national economic growth and innovation, and act as cultural and creative centers. Many development partners and other organizations are active on the topic of resilience in cities, and there has been a recent upswing in the development and promotion of innovate programs, tools, and initiatives. Arup International and the Rockefeller Foundation have developed the city resilience framework, which provides a lens through which the complexity of cities and the numerous factors that contribute to a city’s resilience can be understood. The framework is being used to facilitate agenda-setting sessions in cities selected to participate in the 100 resilient cities challenge. Within this global context, the city strength diagnostic was developed to help World Bank staff apply this new holistic approach to urban resilience to operations. It was designed to help facilitate a dialogue among stakeholders (for example, government, civil society, residents, and the private sector) about risks, resilience, and the performance of urban systems. The city strength diagnostic results in the identification of priority actions and investments that will enhance the city’s resilience as well as increase the resilience building potential of planned or aspirational projects. It stresses a holistic and integrated approach that encourages cross-sectoral collaborations to more efficiently tackle existing issues and to unlock opportunities within the city.

Since 9/11, our world has changed. The threats now facing us are extreme and unpredictable. The potential for terrorists to use public transit to deliver bombs or turn public transit vehicles into bombs underscores the importance of training - training that can help us prepare to deal with the advent of terrorism on a devastating scale. This paper explains how training in teamwork and decision-making aided the reaction of mass transit agencies during the 9/11 attacks. It also describes the new techniques and technologies that can be used to provide even better training for future attacks.

Analysis of actual accident experience in the United States from 1995 to 2000 has revealed that railroad commuter services using a combination of high and low level platforms exhibit a higher injury rate in boarding and alighting accidents than systems with either all high or all low platforms. This paper examines the safety features of these different types of station platforms and the corresponding railroad car entranceways used on these systems. New designs that would incorporate features of the lower accident rate high level only or low level only systems are identified and examined. Estimates of the reduction in the number of injuries that would result from use of these designs are made. The connection to other important performance features impacted by the designs are briefly considered, including cost, speed, meeting Americans with Disabilities Act requirements, and compatibility with freight service. Conclusions regarding the incorporation of boarding and alighting accident considerations in the evaluation of the various car and platform design options as rail passenger lines are upgraded or new services introduced are presented.

This paper presents an overview of current issues in road safety, describes some promising areas of research and provides an introduction for the papers contained in this special issue of the Journal of Transportation Engineering.

Transportation-related injuries are a leading cause of pediatric death, and effective interventions are limited. Otto the Auto is a website offering engaging, interactive activities. We evaluated Otto among a sample of sixty-nine 4- and 5-year-old children, who participated in a randomized parallel group design study. Following baseline evaluation, children engaged with either Otto or a control website for 2 weeks and then were re-evaluated. Children who used Otto failed to show increases in transportation safety knowledge or behavior compared to the control group, although there was a dosage effect whereby children who engaged in the website more with parents gained safer behavior patterns. We conclude Otto may have some efficacy when engaged by children with their parents, but continued efforts to develop and refine engaging, effective, theory-driven strategies to teach children transportation safety, including via internet, should be pursued.

Due to unfamiliarity, international tourists may have higher potential to be involved in traffic related incidents while driving in foreign countries. The study described in this paper evaluated the traffic control device comprehension by international and domestic drivers in the United States, identified other transportation related concerns, and suggested countermeasure ideas useful in addressing transportation and highway safety needs of international tourists. These objectives were achieved by conducting focus group surveys at the departing areas of two international airports in Florida, which is a popular destination among international tourists. Through the data analyses, it was found that more international drivers lack understanding of traffic signs, markings, and traffic signal indications than domestic persons. Based on the identified problem areas, highway safety related countermeasure ideas were suggested for addressing transportation needs of international drivers.

The human limiting values for sudden accelerations we have determined can be used to evaluate specific physical conditions that cause problems in maintaining postural balance. A comparison between the data obtained in the laboratory and the situations occurring during public transport by tram, bus, and metro revealed that both the initial impetus ("jerk") and the level of acceleration found in practice were sufficient to ensure that none of the individuals measured in the laboratory would have been able to retain their balance without extra support. The study suggests that limiting the initial jerk component of the acceleration would help considerably in alleviating the problem.

Occupant restraint systems are designed based on knowledge of crash dynamics and the application of proven occupant-protection principles. For ambulatory children or children who use wheelchairs but can transfer out of their wheelchair when traveling in motor vehicles, there is a range of child safety seats that comply with federal safety standards and that therefore offer high levels of crash protection. For children who remain seated in wheelchairs for travel, the use of wheelchairs and wheelchair tiedown and occupant restraint systems (WTORS) that comply with voluntary industry standards significantly enhances safety. Revisions to the initial versions of these standards will further improve safety for smaller children who travel seated in wheelchairs by requiring wheelchairs for children between 13 and 22 kg (18 and 50 lb) to provide a five-point, wheelchair-integrated crash-tested harness similar to that used in forward-facing child safety seats. While wheelchair and tiedown/restraint manufacturers, van modifiers, transportation personnel, clinicians, and others involved with children who use wheelchairs have clearly defined responsibilities relative to providing these children with safe transportation, parents and caregivers should be knowledgeable about best-practice in wheelchair transportation safety and should use this knowledge to advocate for the safest transportation possible.

Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. Various measures under education, enforcement, and engineering headings being attempted to improve the safety and efficiency of operations at signalized intersections. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on the effects of a countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline make the transferability of models developed in other countries (with more organized traffic) infeasible. The present study is an attempt to analyze the changes in queue-discharge characteristics and red-light violations (RLVs) under Indian traffic conditions due to the presence of a timer. A before-and-after analysis was carried out using the data collected from a selected intersection in Chennai, India. The analysis was carried out for different vehicle types in the presence and absence of timers separately for the start and end of red/green. Results showed that the information provided at the start of green (end of red) enhances efficiency, the start-up lost time is reduced, and there is an increase in RLVs. Two-wheelers present at the start of the queue are found to be the category that is mostly affected by this information. However, the information provided at the end of green (start of red) was found to reduce the incidence of RLVs. In the presence of information, it was found that the propensity of RLV (proportion of cycles having RLV) decreased from 59 to 31% at the end of green (start of red) and increased from 12 to 75% at the start of green (end of red) with a statistically significant drop in the headways (indicating an increased efficiency). Also, in the presence of information, the intensity of RLVs (mean RLVs per RLV cycle) for both the start of red and end of red decreased from 3.32 to 2.30 vehicles and 8.52 to 5.60 vehicles, respectively. The impacts varied based on vehicle type with major impacts on two-wheelers. The queue-discharge models show a significant change in trend, implying a need to update the signal timings when timers are installed. These results also bring to light the trade-off between safety and efficiency and the choices drivers make in the presence of phase-change information. These trade-offs should be carefully considered as the technology advances and drivers are provided with more and more information. For example, with the advent of intellidrive technology (vehicle-to-infrastructure communications), the extent of information provided to drivers should be tailored to achieve system optimality. The results of studies such as this one can help in decision making. � 2012 American Society of Civil Engineers.