Study On Traffic Capacity Of Urban Signal-controlled Intersection Groups

Because of the special plane geometric structure of urban signalized intersection group,it has formed strong spatial and geometric correlation,which has become the bottleneck area of improving urban traffic efficiency and restricted the development of the city.Therefore,this paper takes urban signalized intersection group as the research object,analyses the influencing factors of traffic capacity under various conditions,explores the traffic flow mechanism of intersection group,and finally constructs the traffic capacity model of urban signalized intersection group,which is of great significance for the analysis of the inherent contradictions of the whole urban traffic system and the improvement of traffic efficiency.Firstly,this paper studies the theory of traffic capacity of urban signalized intersections.Based on the analysis of the basic theory of intersection group and the discussion of the method of defining intersection group,the definition of signalized intersection group is studied,and the influencing factors of traffic capacity under ideal conditions,road conditions,traffic conditions,control conditions and other conditions are deeply analyzed and discussed.Secondly,according to the traffic flow characteristics and traffic correlation characteristics of intersections,this paper puts forward the concept of demand capacity,and analyses the traffic capacity of intersections from the perspective of traffic demand and traffic supply.Applying optimization theory,it draws the conclusion that the actual traffic capacity should be the minimum of demand capacity and supply capacity.On the basis of analysis,the calculation model of traffic capacity of signalized intersections is constructed,which is the sum of all traffic capacity of intersections,and the basic mathematical calculation model of traffic capacity and traffic capacity of key entrance roads is put forward.Finally,based on the VISSIM simulation system and the actual road traffic conditions,this paper establishes a traffic simulation experiment model,and determines the relevant simulation parameters.It verifies that the capacity of intersections is the sum of the capacity of each vehicle flow Lane in the intersection group,and the capacity of the vehicle flow Lane in the intersection group is the smaller value of the capacity of the import lane and the turning ratio of the import lane.Finally,a simulation example is designed to validate the correctness of the whole capacity calculation system proposed in this paper by comparing and analyzing the calculation data with the simulation data.