Timing Optimization Of Two-phase Signal Controlled Intersections Based On Conflict Characteristics

With the increasing number of motor vehicles in the country,it not only brings pressure to the traffic situation of the whole society,but also puts forward higher requirements for traffic management.The problems of traffic in the new era need to be effectively solved.At most intersections,the composition of traffic flow is very complex,and the interaction between various traffic bodies is very great.Especially at two-phase signalized intersections,the conflict between left-turning motor vehicles and straight-going motor vehicles is one of the main reasons for increasing traffic delay and reducing traffic capacity.Therefore,it is necessary to study the conflict characteristics of two-phase signalized intersections,and on this basis,to optimize signal timing.Firstly,the research status of signal timing scheme at home and abroad is analyzed and summarized,and the main research content of this paper is determined by taking two-phase intersection as the research object.The characteristics of motor vehicles,non-motor vehicles and pedestrians at intersections and road conflicts at two-phase signal controlled intersections are analyzed,including the types of traffic conflicts,the basic forms of traffic conflict points,the identification methods of traffic conflicts and the severity of traffic conflicts.Based on the actual intersection data of Changchun City,the collision rate and collision number are quantitatively analyzed.The results show that the negative correlation coefficients are above 0.8,and the accuracy meets the requirements.Then,two optimization schemes are selected:Method one is based on the traditional TRRL model to alleviate the overall delay of the entire intersection,combined with the conflict theory of two-phase signal control intersection,based on the delay to determine the flow ratio correction coefficient₄),so as to optimize the timing parameters;The second method is to design the lap phase and calculate the timing parameters according to the uneven flow of left-turning vehicles at the intersection.Finally,taking the intersection of Zhuhai Road and Exhibition Street in Changchun City as an example,Webster delay model was used to calculate the theoretical delay of the two optimization methods respectively,and VISSIM simulation software was used to simulate the two optimization methods.