Research On Traffic Flow Modeling And Simulation Based On Cellular Automaton

Intelligent transportation system (ITS) improvs the situation of transportation systems by managing advanced technologies such as telecommunication, network, automatic control and traffic engineering to, thus establishing an intelligent, secure, convenient, efficient, comfortable and environmental protection transportation system. Traffic flow modeling is one of the most important parts of ITS. ITS can be categorized as microscopic modeling and macroscopic modeling. Microscopic traffic models such as cellular automaton (CA) models and hybrid traffic models arisen in recent years have potential values in application.Based on the theory of traffic modeling, this thesis mainly did some research on CA bicycle flow modeling and hybrid traffic modeling. The main contents and contributions could be summarized as follows:1. In Chapter 2, Two bicycle flow models based on cellular automaton were proposed based on the characteristics of bicycle flow and the behaviors of riders. The relations between vertical speed and horizon speed of a bicycle were considered in the first model which is under open boundary condition. The model could simulate the behaviors of bicycles at intersections very precisely. The bicycle characteristics were described in a more detailed way in the second model which is under periodic boundary condition by adding riders' psychological and physical conditions. Influences of barriers between bicycle lanes and vehicle lanes were also considered in the second model as well. It could be applied to many different road conditions.2. A hybrid traffic model based on CA was proposed in the thesis by analyzing the theory of hybrid traffic modeling. The consistency between the microscopic model and the macroscopic model, the synchronized evolution rules and the information transition between two boundaries were analyzed in the model. The results provided theoretical basis for further research on hybrid traffic modeling.3. The author participated in designing and implementing the traffic intersection simulation system (Tiss). A new concept called signal sequence group was proposed in representing the whole signal sequences of a single intersection. The signal distribution module of Tiss provided the uses to design the signal distribution both manually and automatically. The module could export an optimized signal list according to different inputs imported by users. This structure made signal distribution methods of every intersection to be independent and thus made great convenience for users to design and rectify signal phases for a certain intersection.