Method Of Traffic Flow Analysis And Simulation On Ring Road System Of Urban Expressway Based On Shortest Path Algorithm

ABSTRACT:Urban traffic problem is essentially the embodiment of the conflict between traffic supply and traffic demand, and the combined strategies of increasing supply and controlling demand are always used to solve urban traffic problems. As a way of increasing traffic supply, the construction of urban rapid ring road has been widely applied. However, people begin to pay more and more attention to the scientific and reasonable traffic organization methods with the urban rapid ring road being congestion. The understanding of the ring road has remained in qualitative description lever as a result of lack of quantitative theoretical analysis methods, which impedes the development of the traffic organization of the ring road to some extent.In this paper, the framework of theoretical model to study the urban rapid ring road traffic system is proposed from the angle of quantification. Firstly, the ring road system of circular city is transferred to a uniform rectangular grid system based on topo logical transformation. Secondly, a shortest path algorithm is proposed for normal traffic system, one-way direction traffic system, traffic system with ramps, and the mixed conditions. And then, with the aid of the shortest path algorithm and the uniform rectangular grid system, the framework of theoretical model to study the urban rapid ring road traffic system is built based on the traffic distribution model and the traffic assignment model, and the trip space/time distance and the traffic demand intensity are taken as evaluation indexes. Eventually, different types of the ring road traffic system are simulated.