Study Of Bus Signal Priority Under The Condition Of Intermittent Bus-only Approach

In order to resolve the conflict between bus priority and the general traffic at intersections,setting an intermittent bus-only approach is a new technical method.It provides the space priority for buses,by opening the bus-only approach intermittently to social vehicles and improves the utilization ratio of approach resources at intersections,and then reduce the traffic delay caused by dedicate bus-only approach.However,this new bus priority method only provides the space priority for buses at intersections,this paper tries to study the technical method to provide the signal priority for buses on an intermittent bus-only approach.The main work includes:Firstly,to improve the existing control method of intermittent bus-only approach,and on the basis of the improvement,to create a new bus priority control system which combines intermittent bus-only approach with bus signal priority,and to put forward the concrete steps and control process.Secondly,to study the lane-changing behavior of social vehicles under the intermittent bus-only approach optimal control.Based on the results of the study to calculate the length of vehicle merging road section by gap acceptance theory and differential methods.The storage length of approaches was calculated according to the maximum queue length at intersections.Then,to calculate the distance between the position of VMS and the stop line,which provide the key control parameter to the optimal system.Thirdly,traffic delays were analyzed quantitatively by delay triangle method under the intermittent optimal control before and after the combination of bus signal priority,and come up the formulas of bus and social vehicles delays.And then,the simulation model of the intermittent bus-only approach control system before and after the combination with bus signal priority was founded by the simulation software VIS SIM.Then to analyze the delays of the buses and the queue length of the social vehicles at intersections according to the simulation results.