Using Simulation to Assess and Reduce Conflicts between Drivers and Bicyclists

This paper presents an experiment conducted in a large-screen bicycling simulator to assess the impact of protected intersections on bicycle-vehicle conflicts by examining how bicyclists respond to vehicles making right-hook turns at protected vs. unprotected intersections. Participants were divided into four groups that differed by the road infrastructure (separated bike lane and protected intersections vs. conventional bike lane and unprotected intersections) and the presence (treatment) vs. absence (control) of vehicles making right-hook turns. Turning vehicles were timed to arrive at the conflict point 1 s or 1.5 s before the rider. The results show significant differences in the margin of safety between riders and turning vehicles at the conflict point where their paths cross in protected vs. unprotected intersections. The discussion focuses on the factors that underlie this difference, including the geometry of the rider’s path and the site lines as riders approach the conflict point in protected vs. unprotected intersections.