Dynamic Collaborative Optimization Of Variable Approach Lane And Signal Timing At Intersection

The location of the intersection in the urban road network is critical,and its operation status plays an extremely important role in maintaining the smooth operation of the entire road network.Therefore,it is necessary to adopt a reasonable method to control the intersection in time.However,due to the distribution of urban spatial functions and the differences in the travel period of residents,the traffic flow at the intersection often fluctuates in the distribution of the traffic direction.This kind of problem is usually solved by adjusting the traffic flow at the intersection of the travel time or traffic order.However,when the traffic flow of each turn fluctuates greatly,if the signal control method is still used to solve the problem,the travel time of the traffic flow in other directions will often be shortened,and it is easy to cause the transfer or diffusion of traffic congestion.However,the variable approach lane can change the lane function according to the actual traffic conditions,improve the utilization of road space and relieve the traffic congestion at the intersection.Therefore,how to effectively combine the lane function with signal timing,establish a reasonable and effective dynamic control method,deal with the unbalanced turning traffic demand of the entrance road,and improve the utilization rate of road resources,which is not only of practical significance to alleviate the increasingly serious intersection congestion problem,but also the focus of this paper.Firstly,this paper studies the basic theory of variable approach lane,systematically analyzes the requirements of road channelization,traffic and signal control for setting variable approach lane at intersections,and clarifies the setting method and control form of variable approach lane.Combined with the setting principle of variable approach lane and the analysis of control objectives,and considering the limitations of relying on manual control and lane function switching at fixed time periods,the dynamic control logic of the variable approach lane in this paper is proposed.Secondly,based on the fuzzy control to judge the difference of the queue length of the steering traffic flow,combined with the steering traffic flow saturation requirements before and after the lane function switching,the lane function is judged,and the dynamic control model of the lane function is constructed.Then,the signal timing optimization model is constructed based on the phase of the double-loop structure to realize the coordinated optimization of the time and space resources at the intersection.And analyze the pre-signal coordination relationship after lane function switching to solve the traffic interweaving problem during the lane function change.Finally,Sanlihe East Road and Fuchengmenwai Street are selected as the case intersection.After analyzing the case intersection from the aspects of road channelization and signal phase control,a variable approach lane is set at the entrance.The COM interface of VISSIM simulation software is called by Python to build a dynamic simulation platform.Combined with the changes of traffic conditions in multiple periods,the optimization control method proposed in this paper is compared with other control strategies,which proves the effectiveness of the optimization control method proposed in this paper to reduce the delay of signalized intersection and reduce the queue length.