The Complex Network Model Of Urban Road Traffic System And The Research Of Traffic Jam Phenomenon

The urban traffic network is a carrier where urban system can exist and play a role. The prosperity and development of a city often depend on its superior geographical conditions and convenient traffic facilities. With the development of modern urbanization and improvement of people’s living conditions, vehicle population increased dramatically, and the phenomena of the traffic congestion becomes more and more serious. Traffic congestion will not only increase traveling time and bring great economic loss, but also cause environmental pollution and traffic accidents. How to improve the performance of traffic system and ensure the normal operation of the urban functions is a question which needed to be solved rapidly.The urban traffic system is a typical complex system whose complexity contains the complexity of dynamics, the complexity of topological structure, the complexity of evolutionary process, the uncertainty of traffic system and the multilateral layer of traffic system. The research methods of complex systems can be used on the theoretical study of urban traffic system.Complex networks theory is a theory which is used to study complex systems, and the urban traffic network is a typical complex network. By using complex networks theory, we can study the running mechanism of urban traffic network’s internal functions, and then plan the urban traffic to ease and avoid traffic jams.This paper builds a double urban traffic network model, and study the traffic flow assignment of complex urban traffic network, the Braess paradox, and the cascading failure. The main research work is as follows:(1)According to the characteristics of the double urban traffic network, improving the method of successive averages to save time. The comparing of method of successive averages and its improved algorithm in realizing the user equilibrium assignment indicates that the improved algorithm can effectively reduce the running time.(2)Try to use intelligence algorithm to solve the user equilibrium model. According to the characteristic of double urban traffic network, using improved invasive weed optimization algorithm to solve the user equilibrium model, by comparing with successive averages, indicating the feasibility of the new algorithm.(3)To study the Braess paradox of complex urban traffic network. Try to find the roads which cause the Braess paradox, and compute their impact on traffic overall performance, and then give the reasonable urban planning strategy.(4)Using different ways to select some roads, and improving their traffic capacity, then analyzing their impact on traffic performance, and to find roads which are the most important.(5)Considering the problems which exist in the traditional cascading failure model, try to build a new cascading failure model. By using two cascading failure model on different urban traffic network, indicating that the new model is more reasonable.(6)Considering the recovery capability of the road, and analyzing the impact of the recovery capability on the cascading failure phenomenon. The study of the cascading failure model indicates that the recovery capability can reduce and avoid the cascading failure phenomenon.