Safety assessment of signalized intersections with through-movement waiting area in China

Abstract

Installing the through-movement waiting area (TWA) at the signalized intersections has seen the gradual popularity in the metropolitan cities in China. The traffic design allows the through vehicles to enter the waiting area prior to its green phase and wait for the through green time. Several studies have demonstrated that installing the TWA could improve the operational efficiency of the intersections. However, there is no study specifically conducted to assess the safety performance of the intersections with TWA. The paper implements the traffic conflict technique and ordered probit model to compare the scenarios of intersections with and without TWA, and identifies the significant factors contributing to the severity levels of conflicts occurring at TWA. Results show that: (1) the employment of TWA increases the severity of left-turn crossing conflicts, which has a negative impact on the intersection safety; (2) driving beyond the TWA, vehicle type on the adjacent-right lane, left-turn vehicles entering left-turn waiting area at the inappropriate moment, and the lane position of the through vehicles are the significant factors attributing to the severity of left-turn crossing conflict; and (3) the trailing vehicle type and the lane width of TWA affect the severity of the lane-changing conflict. The findings serve to improve the safety design and operational management of TWA.