Time And Space Optimization Of Signalized Intersection Based On Bus Priority

In recent years,with the gradual increase of the number of vehicles,the phenomenon of urban traffic congestion is serious,and the contradiction between road supply and vehicle demand is becoming more and more prominent.The development of public transport is the only way to alleviate this phenomenon,and it is also China’s fundamental national policy.At present,the main methods of implementing public transport priority can be divided into three categories: space priority,time priority and space-time coordination priority from the perspective of time and space.These methods can bring priority to the buses,but there are also several deficiencies.First of all,the existing methods often focus on through bus,while ignoring the impact of turning to bus on social vehicles;Secondly,the relative position of bus stations and bus lanes is also an important factor affecting the design of bus priority scheme;Finally,the running time of the bus will also affect the generation of bus priority scheme.Therefore,considering the above three factors into a model,the coordinated optimization of time and space is an effective method under the condition of bus priority at the intersection.Firstly,this paper demonstrates the necessity of time and space coordination and optimization of intersections under the condition of bus priority.The time and space coordinated optimization of signalized intersection can effectively improve the traffic efficiency of vehicles at the intersection.Therefore,starting from the necessity of time and space optimization of signalized intersection,this paper analyzes its optimization ideas and methods.On this basis,this paper further discusses the differences and necessity of intersection time and space coordination optimization under the condition of bus priority,so as to make a foundation for the theoretical research of intersection time and space optimization method under the condition of bus priority.Then,this paper proposes a time and space optimization model of signalized intersection based on bus priority.Aiming at the maximum number of passengers that the intersection can pass in unit time,the model designs the basic constraints such as lane allocation,Lane saturation and signal timing of the intersection,as well as the constraints based on bus priority,such as the location and time of bus lane.The final experiment shows that compared with the previous models,the proposed model can make more passengers pass through the intersection in unit time,reduce the delay of passengers at the intersection and improve its traffic efficiency.Finally,in order to further improve the solution speed of the model,the Lagrange relaxation algorithm based on community detection method is selected to solve the model.Based on the basic Lagrange algorithm,the community detection algorithm is introduced to divide the decision variables of the model,so that the large-scale optimization problem can be decomposed into several sub problems that can be solved independently,so that each sub problem can be calculated in parallel,so as to improve the solution speed of the model.Finally,the experiments analyzed that the Lagrange relaxation algorithm based on community detection method can improve the computational efficiency of the model to a certain extent.