Abstract:

In order to fully consider the impact of Back of Queue (BoQ) on upstream node and avoid the queuespillover in short- linked sections,the evolution principle of queuing length in entrance lane is firstly analyzed byusing the traffic wave theory,and a method to calculate the distance from BoQ to stop line in saturation period isdeduced.Secondly,by taking the shortest distance of BoQ in critical line of critical phase as the optimizationobjective,a model to optimize the maximum cycle length is established.Then,8 types of testing environmentsmeeting different traffic requirements are designed,in which the proposed and existing optimization methods arecomparatively investigated by calculating the maximum cycle length and by determining the signal timing schemeson the basis of equi- saturation principle.Finally,the efficiencies of the two methods are evaluated in differenttesting environments via VISSIM simulation.The results show that the proposed method is more effective than theexisting one because the former helps reduce the average queuing length,the average distance from BoQ to stop lineand the average stops in critical line of critical phase,with the decrements respectively being 10.67%,11.36%and 11.01%; what's more,the proposed method also results in an average time delay decrement and an averagestop decrement of the whole test network of 3.86% and 3.81%,respectively,as well as an average vehicle numberincrement and an average vehicle speed increment of 1.19% and 3.58%,respectively．

Key words: traffic congestion, traffic wave, maximum cycle length, back of queue, maximum queuing length, VISSIM simulation