Design and Simulation of Signal Phase for Pedestrians' Twice Crossing at Large Signalized Intersections

Under conditions of mixed traffic, pedestrians' twice crossing (PTC) is one of the effective maneuvers for signalized intersections with particularly large size to enhance traffic safety and efficiency by decreasing conflicts and ambiguity of pedestrians and motorized vehicles. However, it will lead to diminishing of vehicles throughput if the signal phase for PTC is not properly designed. In this paper, a method to design signal phase for PTC at large signalized intersections is proposed. The method is aimed at coordinating pedestrian and vehicle signal phases by making them overlap and by combining them. A limiting factor of the method is also presented, after detailed schemes of pedestrian signal phase being worked out under different assumptions of original vehicle signals and setting conditions for PTC. In order to compare the optional schemes of pedestrian signal phase, an evaluation model with regard to pedestrians' waiting time at different waiting zones and a simulation model to implement the evaluation are constructed. The proposed method and models are also employed to analyze the schemes of signal phase for PTC at a practical signalized intersection.