Active Strategy to Improve the Right-Turn Capacity at Signalized Intersections

Abstract

Conflicts between the right-turn vehicles and crossing pedestrians at signalized intersections not only endanger pedestrians, but also impede the ability of vehicles to execute their runs. The strategy proposed in this study recognizes the fact that the pedestrian volume in the late stage of the pedestrian green (PG) time is often low. Thus, it terminates the PG in advance to provide the right-turn vehicles with a pedestrian-free interval, which quickens the turning movements and improves the right-turn capacity. A rule-based algorithm is developed to determine the PG termination time dynamically, which considers the priority needs of vehicles and pedestrians. The proposed strategy is validated numerically at an intersection in Shanghai, China. The results demonstrate that the proposed strategy could efficiently improve the right-turn capacity and reduce vehicle delays with limited impact on pedestrians. Sensitivity analyses suggest that the proposed strategy is applicable at signalized intersections with high right-turn vehicle volume and moderate pedestrian volume.