Research On Real-time Control And Signal Optimization Of Variable Lanes At Signalized Intersections

The application of variable lanes can alleviate the contradiction between the space-time resources of urban road intersections to a certain extent,but most of the current control methods are fixed-time control methods,which cannot adapt to the short-term changes in traffic pressure.There will still be unbalanced demand for left-turn and straight-through traffic flows in certain periods of time,and also the space resource utilization efficiency is not high.In response to the above problems,if the variable lane function can be changed in time according to the road conditions,the contradiction between the traffic demand of the two direction flows and the utilization of space resources can be better alleviated.In view of this,this article takes the intersections that still have the above problems after setting the variable lane as the research object,and discusses the real-time control method of the variable-lane function and the corresponding signal timing optimization.The main research work is summarized as follows:Firstly,the traffic flow conditions and distribution characteristics under real-time control are analyzed.Secondly,the feasibility analysis of real-time control of variable lanes is carried out in terms of basic road conditions,data acquisition conditions and signal conditions.Then it analyzes the influence of the implementation of variable lanes on adjacent intersections.By measuring the correlation between intersections,it is considered whether the traffic demand of adjacent intersections should be used as an influencing factor for the control of variable lanes.The realization of the variable lane control method provides a theoretical basis.Secondly,the model under the real-time control of variable lanes is proposed and the specific workflow is given.The switching judgment interval of variable lane function is determined according to the analysis result of the left-turn traffic flow.The queue length and saturation of the left-turn and straight traffic at the intersection are calculated.The difference in demand is used as the basis for lane function switching.The calculation method of the lane function switching time and the synergy between the main signal and the pre-signal are also given.A signal optimization model under variable lane real-time control is proposed.Based on the existing signal optimization model,the optimization objectives and constraints are adjusted to meet the signal timing requirements under variable lane real-time control.Finally,improve the algorithm fusion strategy,combine GA algorithm and PSO algorithm to solve the model,ensuring the speed of the model and the search ability of the problem solution.Finally,we take the signal-controlled intersection with variable lane where is still an unbalanced demand for left-turn straight-travel in Jinan city roads as an example,and complete the secondary development of VISSIM software with the help of PYTHON,to realize microscopic simulation model with variable lane intersection.By comparing the operation result of the case intersection under the real-time control strategy and the operation method of the fixed lane function in a fixed period of time,the average delay of vehicles and the length of the queue are selected as the evaluation indicators.The feasibility of the paper’s real-time control method of variable lanes and the effectiveness of improving the utilization of intersection space resources are verified.