Some important intersection nodes in the urban road network are generally defined by a single indicator such as the traffic flow or the number of connected links. It is difficult to ensure the reliability of the road network once the traffic incident in the hub node happens. In this paper, according to the free scale features, the urban road network is simplified as a weighted complex network, in which the traffic impedance is taken as the weight parameter, and a method of the weighted network node importance transmission contribution matrix is proposed. The method comprehensively combines the intersection location in the road network, the number of connected links, and the traffic impedance of associated links, to evaluate the intersection node importance. The node efficiency value is used to represent the information related with the intersection location, meanwhile, the node degree value and the traffic impedance value are fused to characterize the importance dependencies of adjacent intersections in the process of the traffic information transmission. A regional road network in Tianjin is used as a test sample to validate the proposed approach. The cascading failure is simulated on the network by continuously removing important nodes. Simulation results show that the largest subgraph size based on the proposed method falls by 9.10%, as compared with the weighted node contraction method when the top 8 important nodes are continuously removed. These results provide a theoretical basis for the congestion warning for the urban traffic network.

urban road network  /  intersection node  /  traffic impedance  /  complex network