Research Of Traffic Flow For Group Of Freeway Tunnel Based On Cellular Automata

With the making a spurt of progress of modernization construction and continuously improving of our country's economy, infrastructure construction of the highway network was expanding to the central and western regions and becoming more and more perfect in China, extending the structure of bridge and tunnel, tunnel group, continuous horizontal and vertical line and so on, which greatly shortened the highway cargo transportation and travel distance and time. On the other hand, as the continued surge in car ownership in china, leading the existing highway network was becoming more and more crowded, resulting in a lot of traffic problems, such as the destruction of the ecological environment, noise pollution, the existing road network utilization, a large number of traffic accidents etc. In these traffic problems, the freeway tunnel groups of our country, from the point of view of traffic flow, was been the researching objects in this paper. A cellular automata model of road traffic flow is established according to the tunnel group which is a special "bottleneck" road. This paper deeply analyzes the macroscopic mechanism and evolution process of traffic flow of group of freeway tunnel from the microscopic point of view, seeks the traffic flow influence factors of highway tunnel group, and explores the relationship between the various factors, in order to improve the traffic safety and the traffic capacity of the road.Cellular automata, having the characteristic of temporal and spatial discrete isometry, parallelism and local update and evolution of high dimensional, can dynamically describe the invisible in the traffic system of microscopic and macroscopic physical phenomena and the internal coupling mechanism, and is flexible in the application process. It also is a commonly used tool in the transportation industry to establishing in line with the actual situation of the traffic flow model according to different road conditions.In this paper, in order to make a thorough analysis and according to the basic characteristics of highway tunnel group traffic road, the traffic flow CA model of the single tunnel, expressway tunnel group and the highway tunnel group of effects of the accident were established. And through the numerical simulation analyzing how effects of the characteristics of traffic flow to affect the capacity of highway tunnel group. The main work is as follows:First, summarizing the current research status and literature review was summarized in order to find the existing problems and gaps in the field, and Expressway Tunnel Group was discussed from the aspect of traffic flow.Second, In order to establish a cellular automata model of expressway tunnel group, the division of highway tunnel group section method, tunnel import and export the driver's visual characteristics, traffic characteristics, the operating environment characteristics and the characteristics of traffic accident were comprehensive analysis to prepare for the further analysis of traffic flow.Third, Numerical analysis the CA model of traffic flow of single highway tunnel, that has been built, including the evolution process of the vehicle and the change process of the overall traffic flow and average speed influencing on the road traffic capacity.Fourth, according to analyzing the visual characteristics of the driver of single tunnel for different types of highway traffic flow characteristics, highway tunnel group which is a mode of "normal"- "bottleneck"- " transition"- "bottleneck" … was been the focus of research, and expanding the cellular automata traffic flow model when the tunnel group traffic accidents.Fifth, Numerical analysis the CA model of traffic flow of highway tunnel group and considered the effect of traffic accidents, that have been built, including the length of transition section, the characteristics of Horizontal and vertical linear, the proportion of idle, the tunnel safety distance, the accident work time and work length and speed limit value in front of the accidents area, which influence on the capacity of whole tunnel group.Finally, summarizes the research results and the problems to be studied.