Comparison of Dilemma Zone and Driver Behavior of Trucks and Passenger Cars at High-Speed Signalized Intersections

Trucks have different dynamic performance and stronger willing of passing the intersection during the yellow light comparing with passenger cars. These differences can result in different behaviors conflicts and high safety risks at high-speed intersections. This paper investigates the driver behavior and dilemma zone of trucks and passenger cars at three high-speed signalized intersections in Shanghai. The authors use statistical methodology considering both type I dilemma zone and type II dilemma zone. Based on the field observation, it is found that there are significant differences in both type I dilemma zone, type II dilemma zone and red light running behavior between trucks and passenger cars. According to the stop/go decision of field observation, a calibration of parameters of type I dilemma zone is conducted based on vehicle types. The differences mentioned above can lead to both serious right-angle and rear-end conflicts. Thus an all-red extension strategy based on truck exclusive-approach lane was proposed to provide additional protection for trucks. The quantitative simulation evaluation shows that it can reduce the vehicle conflicts significantly and reduce the intersection delay as well.