IATSS Research最新文献

Given the dangers pedestrians are susceptible to when crossing the roadway, an investigation of motorists' yielding decisions at uncontrolled crossings should be prioritised. Some encounters between motorists and pedestrians turn into injuries or deaths due to excessive delay on the part of drivers, and pedestrians' impatience might lead them to opt for the rolling gap. Insights into drivers' yielding behaviour in developing countries are lacking. Meanwhile, developing countries contribute significantly to traffic deaths, particularly those in the African Region. Understanding drivers' yielding behaviour is necessary for effective interventions to safeguard pedestrians and encourage safe walking. Accordingly, by deploying a backward binary logit model, this study investigated drivers' yielding behaviour at marked uncontrolled pedestrian crossings through naturalistic observation. The results revealed that a small share of drivers, 258, were observed to yield to pedestrians, representing a 28% yielding rate in total. The model indicates that the chances of motorists yielding to pedestrians are enhanced by the following factors: pedestrian age, density, gender and traffic condition. Private car drivers had the lowest yielding rate of 18.2%, followed closely by public transport drivers. This research contributes to the discourse on drivers' yielding behaviour at pedestrian crossings with perspectives from a developing country. Further, it discusses policy implications for policymakers and enforcement agencies.

The Safe System approach is a commonly adopted approach internationally to address road traffic injuries. Existing research has identified that the approach has multiple descriptions, and there have been noted difficulties associated with implementation. Practitioners have an important role in rolling out road safety interventions, and thus are a key point for translating Safe System into practice. However, there has been limited investigation of how practitioners view and understand Safe System. Of particular importance is practitioners' interpretation of Safe System's purpose and the facilitators and barriers to application. Four hundred and sixty-nine respondents completed an online survey which investigated perceptions regarding Safe System's purpose.

The results highlight that practitioners view Safe System as being multidimensional, with a range of ideas about what the overall purpose is. Safe System was perceived as both visionary and practical, with the majority of respondents reporting that it defines a broad outcome for road safety and provides direction on how to respond to road traffic injury. Additionally, two thirds of respondents identified that they applied Safe System to the last project or program they worked on and were broadly supportive of the approach. However, multiple impediments to application were identified, with these barriers effected by the practitioners' demographics, role and organisation. For practitioners, Safe System represents a complex approach that aims to reduce injury and deaths, however, effective application can only occur when barriers are reduced.

Despite having the highest accident risk of all motorized vehicles, motorcycles are rapidly gaining popularity in Asian countries because of their affordability and flexibility. In response to this trend, many studies in Asian countries have examined the prevalence of motorcycles and assessed their impacts. In order to identify significant studies on motorcycles, this study conducts a bibliometric analysis of motorcycle studies in Asian countries. The data were gathered from Scopus and Web of Science databases over the entire publication period from 1971 to 2022. This study uses VOS-viewer and Biblioshiny to highlight important indicators, including source, authorship, country, institution, citation, co-citation analysis topic classifications, and keyword occurrences. A total of 2529 articles from journals and conferences were examined. The results reveal that published studies of motorcycles in Asian countries increased by an average of 22% after their initial appearance in 1971. Motorcycling studies in Asia have evolved from focusing on safety (1971–2000) to broader themes including emissions (2001−2012), the built environment's impact on energy (2013–2019), and recently towards advanced technology and urban sustainability (2020−2022). IATSS Research is ranked seventh with the most motorcycle articles. China, including Taiwan, has the most articles and citations among Asian countries. Based on the publication themes, the 51 years of motorcycle studies in Asia can be categorized into five clusters: accidents and human factors, traffic and policy, air pollution, motorcycle engineering and performance, and roads and technological innovation. Finally, eco-friendly fuels for motorcycles, diversity of motorcyclist behaviors in Asia, and technology-based driving safety are significant topics for future studies.

A study was conducted to analyze the factors affecting violation behavior among road users in Thailand and Japan in order to determine appropriate policies and recommendations. The study used the theory of planned behavior (TPB) to evaluate road user behavior and attitude. Questionnaires were distributed in Bangkok, Thailand and Sapporo, resulting in 477 valid responses in Thailand and 201 in Japan. The data was analyzed using structural equation modeling (SEM). Results showed that notice failure and bicycle stunt were the most impactful factors for the bicycle model in Japan, while instrumental attitude and conformity tendency were significant for the pedestrian model. In Thailand, traffic errors and motorcycle stunts were the most impactful factors for the motorcycle model, while instrumental attitude, descriptive norm, and conformity tendency were significant for the pedestrian model. The study suggests promoting awareness of violation and accidents, teaching proper motorcycle riding techniques, and creating safe environments to prevent accidents. It also recommends cultivating consciousness in individuals behavior and emphasizing the importance of traffic rules to parents and companions.

The location of level crossings for pedestrian circulation is a safety issue due to potential human losses and material damage. This problem has become a concern in urban and industrial environments due to the characteristics of rail systems and unsafe pedestrian behaviour. Research reveals that psychological and infrastructural factors influence pedestrians' decision-making when crossing railroad lines. One of these is the convenience that leads pedestrians to cross at the nearest point. However, investigations to date only study the impact of location on the risk and severity of crashes and pedestrian rule violations. The current research is quasi-experimental, i.e., no optimisation tool has been developed to determine which crossing points pedestrians should follow. Therefore, this research develops a mathematical model for locating level crossings at railways to minimise the total weighted-walked distance. A genetic algorithm was proposed for solving the model, especially for large-size problems. The algorithm parameters were calibrated using the design of experiments and ten instances based on the characteristics of the area under study. The obtained results provide (1) the location of the level crossings and (2) the route pedestrians should follow for each origin-destination pair based on the facilities adjacent to the rail lines. A sensitivity analysis was performed using the ten instances to determine how the location of the level crossings changes with modifications in the facilities' location. Results showed that the model provides alternative solutions according to the problem's size. This study delivers a methodology for practitioners and stakeholders of transportation systems.

Objective

Indonesia experiences a high number of motorcycle accidents at railway crossings (RLXs). The purpose of this study is to observe motorcyclists' behavior and intent to cross the railway in a dangerous or illegal way and the factors influencing these decisions.

Method

Two hundred and fifty-nine people (mean age = 24.2 years, SD = 7.2 years, 146 males, 113 females) voluntarily participated in this study by filling in an online questionnaire. This questionnaire gathered demographic data and used constructs adapted from the extended Theory of Planned Behavior, asking respondents about their behavior at RLXs when the barrier is open, when it is half closed and when it is fully closed. A five-point Likert scale was used to measure the response of the questionnaire. Data were analyzed using descriptive analysis for demographic data, inferential statistics, and structural equation modeling (SEM) for the construct items of the model. Field observation was also conducted to measure the violation rate at RLXs at both busy and non-busy times, which were then compared.

Result

The results show that factors influencing RLX violation based on the extended Theory of Planned Behavior model are attitude, past behavior, and traffic environments. Demographic factors, occupation, RLX characteristics, and crossing frequency were related to self-reported violations and intentions to violate. Based on our observations and questionnaire, it was found that when accident risk was higher, the observed violation rate decreased significantly, as did intention to violate and previous risky crossing behavior.

Conclusion

violations at railway crossings are influenced by individual and environmental factors as well as perceived risk.

Time headway characteristics are of great importance for planning and design of roadway. The present study determines time headway distribution pattern of vehicular stream at various urban roads and evaluate drop in capacity of roadway section having curb-side bus stops. Field data for present study was collected at 8 different locations on four-lane and six-lane divided sections in the cities of Warangal and Hyderabad in India. The mean time headway of heterogeneous vehicles fitted to various headway distributions for estimating capacity of road section. The factors affecting the capacity have been identified as bus frequency, dwell time, and the average roadway width lost. Percentage reduction in capacity (PRC) is determined to develop regression model. Further, speed-flow diagrams were developed using field observed traffic flow data for determining parameters free-speed, critical speed, and roadway capacity on selected section. After comparing capacity values obtained from two methods, the study determined avg. time headway of vehicular stream under the traffic flow at capacity and free flow conditions. The study also finds capacity value of bus stop section using methodology provided in Indo-HCM (2017). The PRC values estimated based on Indo-HCM guidelines are found to be significantly higher than those estimated by the proposed PRC model. It is due to the Indo-HCM guideline considering only one parameter i.e. bus frequency. The study finds, in addition to bus frequency the dwell time, roadway width lost, and presence of an extra lane also influences the drop in capacity of bus stop section on multilane divided urban roads.

A Traffic Conflict Technique is a proactive approach that identifies observable critical vehicle interactions (conflict) that could have led to a crash. This paper develops conflict-based safety performance functions (SPFs) to predict the number of traffic conflicts at the signal cycle level in mixed traffic conditions with poor lane discipline (disordered traffic conditions). 9586 vehicle trajectories were extracted from traffic video data collected from 4 signalized intersections in India. Critically interacting vehicle pairs were estimated using Time to Collision (TTC). The conventional surrogate measure is modified into a 2-dimensional surrogate approach which captures the conflicts by incorporating the vehicle dimension, heading direction, position, speed, and acceleration in the longitudinal and lateral direction between vehicles. Rear-end and side-swipe conflicts are identified at varying threshold values to incorporate severity. Rear-end conflict SPFs show that higher conflict occurrence is expected during signal cycles with more traffic volume, higher vehicle arrival speed, more right-turning traffic, and a lower platoon ratio. At severe threshold (TTC ≤ 1 s), one 1 m/s increase in speed of vehicle increases the expected number of rear-end conflicts by 6%. Furthermore, SPFs show that severe side-swipe conflicts are expected during signal cycles with more lane-changing maneuvers and right-turning vehicles. For TTC ≤ 1 s, one unit increase in the number of lane changes would increase the expected number of sides-wipe conflicts by 7.9%. The finding of this study can be most beneficially used for arriving at policy measures and improving the safety of signalized intersections in disordered traffic conditions.

Pedestrian red-light violation is one of the crucial causes of pedestrian crashes at urban intersections, which cause considerable injuries and casualties to this vulnerable road group of road users. The objective of this study is to evaluate the risk of pedestrian-vehicle collisions by clustering the pedestrians' red-light violations using surrogate safety measures. The present study utilized surveillance camera footage to collect data on pedestrians' red-light violations at two urban intersections in Babol City. Based on critical thresholds of post-encroachment time (PET), Time to Collision (TTC), and Gap Time (GT), three different risk levels of red-light violations were identified through the use of a K-means algorithm. Moreover, structural equation models were developed for each of the risk levels considering variables that are associated with four major components: human, environment, road, and vehicle. Lastly, policy insights into amending pedestrian behavior and promoting traffic safety culture were proposed, with an overarching emphasis on the human factor, due to its identified greater influence on the propensity for red-light violations.

This paper presents a framework for monitoring highway traffic-stream measures using quality trajectory data of mixed (heterogeneous) traffic. The framework includes a new measure that reflects the attentiveness of the follower driver, called receptiveness angle, in the vehicle-following process. This measure is integrated with the traditional measures (distance gap between the leader and follower vehicles and their speeds) to model the probabilistic rear-end collision interactions between the two vehicles. To verify the proposed framework, two road sections in India with mixed traffic conditions, located along the same road, were used. One section has no construction activity (base section) and the other has construction activity. The verification consisted of two tasks. First, to trace the movements of the vehicles, trajectory data over the study sections were developed for three traffic-flow levels, where two flow levels between the two sections were comparable. Second, the trajectory data were used to verify the proposed framework which was evaluated for the traffic streams of the two sections at the three traffic-flow levels. The results showed that smaller vehicles in the traffic stream exhibited a higher receptiveness angle (paid less attention) compared to other vehicle classes. Interestingly, the study revealed variations in safety among the three traffic-flow levels. It was observed that the traffic stream was safer at stop-and-go conditions than at other flow conditions. Furthermore, due to the pre-cautioning measures for the construction section, vehicles in this section were more attentive than those in the base section.