Study On Traffic Design Of Contraflow Left-turn Lane Intersection

With the continuous growth of the economy,the number of motor vehicles in our country has been increasing,the traffic demand has expanded dramatically.Urban road traffic congestion and driving accidents have become more serious.Signalized intersections are important nodes in the urban road network.Due to the inadequate utilization of road space resources,channelization and signal timing are unreasonable,resulting in intersections becoming a high incidence of road traffic congestion or accidents.To this end,the traffic management department has proposed a series of transportation organization methods that rationally use the space-time resources of roads to improve the ability of peers at intersections.However,in reality,there are still insufficient utilization of space resources at intersections and the effect of congestion control is not satisfactory.In multi-directional traffic flow,left-turn traffic has the greatest impact on the intersection,so optimizing left-turn traffic has become the key to traffic organization at intersections.First of all,based on the traffic organization characteristics of urban road intersections,this paper analyzes the left turn traffic flow of intersections in terms of the traffic impact of left turn traffic flow,the complexity of left turn traffic flow and the traffic characteristics of left turn traffic flow.Based on the commonly used left turn traffic organization methods of intersections,this paper introduces the concept of the reverse variable lane,and summarizes the advantages and disadvantages of the reverse variable lane and setting conditions.Secondly,through the analysis of the setting of left turn lanes at home and abroad,the geometric parameters of reverse variable lane are studied,including the length,width,opening length of central separate belt,number of lanes and pre signal timing of reverse variable lane,and the calculation model of the number of lanes is optimized.At the same time,the setting method of traffic management facilities in the left turn lane is studied.At last,the practicability of the reverse variable lane is analyzed by VISSIM simulation software,and the benefit practicability is evaluated and analyzed.Combined with the actual case,based on the current geometric layout of the intersection,traffic survey data,a comprehensive evaluation of the left turn intersection is carried out.The purpose of this paper is to make full use of the time and space resources of urban road intersections based on the existing road resources.The most important thing is to provide scientific and effective design and management basis for engineering designers and traffic managers,and provide methods to relieve the left turn traffic pressure of urban road intersections.