Date of Award
College of Science, Engineering, and Technology (COSET)
MS in Transportation Planning & Management
At the intersections with permissive only signal control, pedestrians will move at the permissive phase with the parallel through vehicular movement and left-tum vehicles, the left-tum vehicles have to yield to both opposing vehicles and pedestrians at crosswalk. Under such complicated driving conditions, collision risks rise if left-tum vehicles make misjudgments and fail to yield to the pedestrians. The exiting warrants or guidelines on left-tum operations are mainly focus on the traffic conditions at the intersections and do not give particular considerations on the pedestrian safety problems. They are developed mainly based on the left-tum and the opposing through traffic volumes, while the pedestrian volumes and other pedestrian safety related factors, such as the design features of the crossroads, and the heavy vehicle influence on the left-tum drivers have not been explicitly taken into account. This research attempts to achieve two goals: 1) determine factors that contribute to the crashes between left-tum vehicles and pedestrians during the permissive left-tum phase, and 2) assess the impacts of the factors that contribute to the crashes between left-tum vehicles and pedestrians under different traffic and geometric conditions during the permissive left-turn phase. 1 2 To achieve these goals, driving-simulation based experiments were conducted to identify and assess the impacts of the factors that contribute to the crashes between left-turn vehicles and pedestrians under permissive left-turn control. After that, a survey was conducted to the participated drivers to get their subjective assessment of the pedestrian safety at different intersections with various traffic and geometric conditions. The key findings of this study include: 1) Tuck on the left-turn lane block the view of other left-turn vehicles will increases the risk of collisions between permissive left-turn vehicles and pedestrians significantly, 2) The probability of collisions between permissive left-turn vehicles and pedestrians will increase with the increase of pedestrian volume, 3) The collision risk will increase with the increase of opposing through traffic and then decrease after the opposing through traffic reaches a certain degree, and 4) Four-leg intersections will cause more collisions between pedestrians and permissive left-turn vehicles comparing with three-leg intersection
Guo, Aohan, "Pedestrian Safety Under Permissive Left-Turn Signal Control" (2012). Theses (Pre-2016). 61.