Study Of City's Traffic Bottleneck With Cellular Automaton Model

Cellular automation model is a new way to research the non-liner dynamic system which takes discrete variable in time and space. It can simulate complex natural and society phenomena based on some very simple rules and get good results. Due to the characteristics of easily simulated computing on computers and flexibility, it is widely used in many disciplines in recent years. Great progress has been made especially on the research of traffic flow of a cellular automation model. In the process of traffic flow theory development, scientists always concern researches on the causing and dispersing of traffic jams. Because of various actual conditions, there are always different traffic bottlenecks, some of which are caused by the traffic accidents; some by inhomogeneous roads; some by on- and off-ramp. In general all kinds of bottlenecks are being studied except the one caused by city bridges. we set a bridge bottleneck model in this paper according to the actual bridges. After simply introducing the cellular automation traffic model and its theoretical base, several classical cellular automation models are used to simulate and analyze the consequence of bridge bottlenecks in the traffic flow.In this paper, the first part introduces the development and application of current traffic flow models and various research situations of bottleneck models. The second part puts the simplest cellular automation traffic flow model (No 184 single lane rule) into the use of bridge bottleneck ones, then by using computers simulates that there are the characteristics of complex dynamics of all lanes of the whole system and vehicle distributing instability. Based on this, the third part, according to the characteristics of traffic flow and mean-field theory, analyses the vehicle distribution in various lanes and the flow distributing in lanes. Thus the computing results totally tally with simulating ones. The author explains the reason of vehicle scattering qualitatively and gives some suggestions on the administration of bridge bottlenecks. To get closer to the actual traffic flow, in the fourth part, the more actual traffic flow cellular automation model-N-S Model are applied in the bridge bottleneck transport. The author analyses different system properties under different transport rules at bridge intercrosses and puts forward models with transport intervene and those without intervene. The simulating shows that there is a self-organization phenomenon of the moving vehicles at bridge bottlenecks. In the fifth part, definitive N-S model are applied in the bridge bottleneck, some interesting consequence are found.