Impacts of visual and cognitive distractions and time pressure on pedestrian crossing behaviour: A simulator study.

Distractions have been recognised as one important factor associated with pedestrian injuries, as the increasing use of cell phones and personal devices. However, the situation is less clear regarding the differences in the effects of visual-manual and auditory-cognitive distractions. Here, we investigated distracted pedestrians in a one-lane road with continuous traffic using an immersive CAVE-based simulator. Sixty participants were recruited to complete a crossing task and perform one of two distractions, a visual-manual task and an auditory-cognitive task. Moreover, normal and time pressure crossing conditions were included as a baseline and comparison. For the first time, this study directly compared the impacts of visual-manual, auditory-cognitive distractions, and time pressure on pedestrian crossing behaviour and safety in a controlled environment. The results indicated that although pedestrian safety was compromised under both types of distraction, the effects of the applied distractions were different. When engaged in the visual-manual distraction, participants crossed the road slowly, but there was no significant difference in gap acceptance or initiation time compared to baseline. In contrast, participants walked slowly, crossed earlier, and accepted smaller gaps when performing the auditory-cognitive distraction. This has interesting parallels to existing findings on how these two types of distractions affect driver performance. Moreover, the effects of the visual-manual distraction were found to be dynamic, as these effects were affected by the gap size. Finally, compared to baseline, time pressure resulted in participants accepting smaller time gaps with shorter initiation times and crossing durations, leading to an increase in unsafe decisions and a decrease in near-collisions. These results provide new evidence that two types of distraction and time pressure impair pedestrian safety, but in different ways. Our findings may provide insights for further studies involving pedestrians with different distraction components.

Effects of mobile phone distraction on pedestrians' crossing behavior and visual attention allocation at a signalized intersection: An outdoor experimental study.

With the rapid growth in mobile phone use worldwide, traffic safety experts have begun to consider the impact of mobile phone distractions on pedestrian crossing safety. This study sought to investigate how mobile phone distractions (music distraction, phone conversation distraction and text distraction) affect the behavior of pedestrians while they are crossing the street. An outdoor-environment experiment was conducted among 28 college student pedestrians. Two HD videos and an eye tracker were employed to record and analyze crossing behavior and visual attention allocation. The results of the research showed that the three mobile phone distractions cause different levels of impairment to pedestrians' crossing performance, with the greatest effect from text distraction, followed by phone conversation distraction and music distraction. Pedestrians distracted by music initiate crossing later, have increased pupil diameter, and reduce their scanning frequency, fixation points and fixation times toward traffic signal area priorities. In addition to the above effects, pedestrians distracted by phone conversation cross the street more slowly, direct fewer fixation points to the right traffic area, and spend less fixation time and lower average fixation duration on the left traffic area. Moreover, pedestrians distracted by texting look left and right less often and switch, distribute and maintain less visual attention on the traffic environment. These findings may inform researchers, policy makers, and pedestrians.

A risk assessment study on accidents at French level crossings using Bayesian belief networks.

Level crossing (LX) safety continues to be one of the most critical issues for railways despite an ever increasing focus on improving design and practices. In the present paper, a framework of probabilistic risk assessment and improvement decision based on Bayesian belief networks (PRAID-BBN) is proposed. The developed framework aims to analyse various impacting factors which may cause LX accidents, and quantify the contribution of these factors so as to identify the crucial factors which contribute most to the LX accidents. A detailed statistical analysis is first carried out based on the accident/incident data. A BBN risk model is established according to the statistical results. Then, we apply the PRAID-BBN framework on the basis of the accident/incident data provided by SNCF, the French national railway operator. The main outputs of our study are conducive to efficiently focusing on the effort/budget to make LXs safer.

A new insight on the risky behavior of motorists at railway level crossings: An observational field study.

Accidents at railway level crossings (LXs) give rise to serious material and human damage. Particularly, collisions between trains and motorized vehicles are the most critical accidents occurring at LXs. It is worth noticing that violations committed by vehicle drivers are the primary cause of such accidents. The present study is a tentative to acquire a better understanding of risky behavior of vehicle drivers while crossing LXs during the closure cycle. Namely, risk analysis based on field measurement conducted at four automated LXs with two half barriers is performed. We focus on vehicle driver behavior during the LX closure cycle while distinguishing between different phases. In fact, the closure cycle is divided into three phases which are "Ph2 Red Flash and Siren", "Ph3 Barriers Coming Down" and "Ph4 Barriers Down"; and vehicle driver behavior in each phase as time increases is scrutinized respectively. Particularly, zigzag scenarios are detected, using an original experimental setting that we have implemented, and analyzed in detail. The main findings based on the analysis demonstrate that the peak of violation rate in the morning is later than the actual rush hour in the morning; a distinct peak of the violation rate shows on Friday, while the violation rate on weekend is fairly low; the relative violation rate of vehicles with high speed decreases continuously as time advances from Ph2 to Ph3 in the daytime; the violation rate during Ph4 decreases as Ph4 duration is prolonged, which contradicts a general speculation that a higher rate of zigzag violations would appear as the duration of Ph4 is extended. These findings open the way towards determining the impacting factors which have an important contribution to the vehicle driver decision-making in this context (e.g., traffic density, time schedule and phase duration). In addition, the outputs of the present study are conducive to identifying potential interventions to improve safety at LXs.