Although signal countdown timers (SCTs) are likely to enhance efficiency at signalized intersections, there is little research on how they affect road users’ behavior. The present study explores factors associated with driver behavior through two approaches to examine how SCTs influence drivers’ actions toward pedestrians violating red lights. In the first approach, through an on-road questionnaire survey, the self-reported behavior of 369 drivers when crossing an intersection enabled with SCTs was analyzed. In the second approach, the drivers’ behavior was studied through naturalistic driving studies at two signalized intersections equipped with SCTs in Babol, Iran. Analyzing vehicle–pedestrian conflicts indicated that the presence of SCTs had a significant influence on driving behavior. Also, the ending seconds of green lights, as critical times of the SCTs, led to changes in driving behavior. Increasing the vehicle speed, changing lanes, and concurrent increases of speed and changing lanes were the common driver actions affected by critical times of the SCTs. Finally, the effect of critical times on drivers’ actions during conflicts was modeled by using the binary and multinomial logistic methods. The results show that SCTs are an external factor that can lead to risky driver behavior, such as errors and violations that might increase the potential for pedestrian accidents.@en

Children are one of the most vulnerable population groups in traffic crashes. Child safety seats (CSSs) can reduce the severity of crash outcomes for children. The use of CSSs has significantly increased in the U.S. over the last 40 years, but the use of CSSs in popular ridesharing services (RSSs), such as Uber and Lyft, is not widespread. This paper used a publicly available nationwide online survey designed to understand the knowledge and attitudes of drivers and riders toward child passenger safety in RSSs. This study performed a rigorous exploratory data analysis to identify key insights about the survey participants. A recently developed dimension-reduction method was applied to understand the co-occurrence patterns of the responses to gain intuitive insights. Finally, open ended responses of survey participants have been analyzed for further insights. The findings of this study can be used to promote new safety legislation and the use of CSSs in RSSs.@en