Connecting Gap Acceptance Behavior with Crash Experience

While a basic understanding of drivers’ gap acceptance behavior may be understood, many unanswered questions remain, particularly regarding the safety-related impacts associated with this behavior. Previous work has attempted to address these questions, yet limitations in scope have continually emerged as a result of challenges associated with the collection of high fidelity gap acceptance data in the field. This research directly addresses the safety-related implications of driver’s gap acceptance behavior with a large-scale data collection effort of detailed gap acceptance data. Using the data set collected in the large-scale field test using a newly developed software package, factors that appeared to affect drivers' gap acceptance decision-making, and had clear implications on safety, were identified. Different driver groups, specifically different age and gender groups, displayed different gap acceptance behavior. The factors that had the greatest affect on gap acceptance behavior were the presence of a queue behind the driver, driver wait time, and number of gaps rejected. These factors, relating to drivers feeling pressure or simply impatience, resulted in drivers accepting shorter gaps and sacrificing a degree of safety to execute their turn. Identifying and analyzing "gap acceptance related” crashes, connections were drawn with the results of the gap acceptance analysis. Driver groups displaying more aggressive gap acceptance behavior, male drivers and teen drivers, are overrepresented in gap acceptance related crashes. Development of a better understanding of these connections has the potential to translate into more targeted solutions to the gap acceptance related crash problem.