A Study On Dynamic Traffic Assignment Based On Simulantion

With the economy growth and the rapid increase of automobile, traffic jam is becoming more and more severe, and it is an imperative problem what kinds of traffic control and guidance methods can be applied to lighten it and effectively improve traffic systems' efficiency. Dynamic traffic assignment is the key to this problem, and it plays an important role in the traffic control and guidance. From the point of view of research methodlogy, the development of dynamic traffic assignment theory includes mathematic programming model,optimal control model,VI model and computer simulation model .although from the point of academia, the attraction power of computer simulation model to researcher is inferior to mathematic analytic model but computer simulation can describe dynamic traffic lively. Firstly this paper introduces the significance of the dynamic traffic assignment and the research status of native and foreign countries.and lucubrate some questions about dynamic traffic simulation.It mainly includes several parts as follows:The formulate to estimate link travel times for dynamic traffic assignment; In the part of traffic assignment method,this paper adopt an improved Logit model,it improves the algorithmic speed and efficiency; in the part of the decision of OD matrices for dynamic traffic flow,it gives different λpresented different traffic status to get method how to decide OD matrices for dynamic traffic flow. Lastly this paper provides the output of the system simulation and analyzes the output.