A Transit Priority Model for Arterial Roads Based on the Delays of Upstream and Downstream Intersections

The coordination of green-wave and the efficiency of downstream intersections are affected by the transit signal priority (TSP)set up at the upstream intersections.In order to address this issue,a TSP model that considers the delays at the upstream and downstream intersections along arterial roads is presented in this paper.The extension of green light phase and the reduction of red light phase are used in the model.The weighted delays of upstream and downstream intersections are used as the performance index.This model ensures the transit priority and reduces its impacts on green-wave coordination.It is validated by Vissim simulation in this study.The results show that the average vehicle delay at down-stream intersections decreases by 10%,although the average vehicle delay at upstream intersections increases by 2.6%.The weighted delay of upstream and downstream intersections decreases by 3.7% comparing with the isolated TSP control strategy.The study results clearly show that the strategy in the proposed model can reduce the conflict between the TSP and the green-wave coordination.