Urban Microscopic Traffic Simulation & Its Application

Since 80's, many countries have built modern road networks. With the development of economy, the traffic capacity cannot catch up with the traffic raising. Traffic congestion is being worse and worse. Taking traffic control and accident management under such condition requires a clear understanding of traffic flow characteristics. For this purpose, during the past fifty years, a wide range of traffic flow theories and models has been developed. These models are classified to submicroscopic model, microscopic model, mesoscopic model and macroscopic model according to the level of detail.In the past, the hot point is the macroscopic model, which discusses the relationships among the traffic stream variables-speed, flow and density. Since the development of computer science and need of traffic simulation, the focus is transferred to microscopic models. Microscopic model calculates position, speed and acceleration of every vehicle in net at each moment. It can offer great deal of information to traffic management and simulation.This dissertation focuses on microscopic traffic modeling and urban microscopic traffic simulation system. The main contents are listed as follows:(1) Establish a vehicle action model, including car following model, lane changing model and nearby vehicle's effect model. The model takes enough consideration of the nearby vehicle's influence and drivers' response delay, which makes the model more realistic.(2) Develop an urban microscopic traffic simulation system, which involves vehicle generation model, network model, traffic regulation model, signal control model, vehicle action model, route choice model and intersection turning model.(3) Realize and Research the method that signal cycle and phases are assigned by the traffic need. When vehicles OD is known, this method can be used to decide the maximum traffic capacity of signal-controlled intersection and the evaluation reference of current control method.(4) Realize the visual part of the urban microscopic, traffic simulation system on graphic workstation OCTANE, by which we can observe real time traffic condition from different viewing positions.(5) Evaluate the urban microscopic traffic simulation system according to test data of typical section.