Optimization Method of the Cycle and Critical Phase on Signal Control Intersection

Signal timing optimization is one of the most important methods that improve the intersection serve level. The paper studies the signal optimization method that the phases have overlapped phase, the bi-level optimization method is used to solve the questions. Firstly, the critical phase is introduced in detail. Then the cycle optimization method TRRL and ARRB is described. Based on the cycle optimization method, the critical phase optimization method is given. Through an example, it is tested that intersection´s average delay is decreased by 21.37%, the average vehicle queue is decreased 10 pcu/c, the intersection capacity is increased 0.93% and the saturation of the intersection is reduce from 1.38 to 0.93. It is proved that the method given in this paper can make the signal time more effectively and the intersection has better serve level.