Integrated Optimization Method for Left turn Phases of Adjacent Junctions

Abstract:

Based on an analysis of the available routes for left turn movements, a set of constraints was set up to optimize left turn phases coordinately including flow conservation, duration of green, degree of saturation, cycle length and so on. Capacity gap computation model was proposed between adjacent intersections with different left turn phases, then, with the objective of minimizing capacity gap, integrated optimization model for left turn phases of adjacent junctions was formulated. Based on the geometry layout and traffic flow data of two field intersections, average vehicle delay and maximum throughput were applied to a comparative evaluation of the field method, Synchro based method and the proposed method. The results show that with the proposed method, the capacity gap between the adjacent intersections and the delay decreases, while the capacity enlarges in comparison with the field and Synchro based mothod with only a slight adverse effect on the system.