Traffic congestion has seriously hindered the healthy and sustainable development of economy and society. Many research have been done to address the issue. Intelligent Transportation System (ITS) is key to improve the performance of urban traffic. As one of the essential components of an ITS, green ITS navigation for people and freight is critical, its research must base on the accurate grasp of real-time traffic conditions and the complex nature of the transport network. In order to provide more accurate traffic state information for ITS navigation, we study the traffic bottleneck which is the source of congestion based on complex network and user equilibrium model in this paper. We identify the bottleneck and evaluate its importance according to the consequences of the road failure from two aspects of the traveling cost and the network effectiveness. Furthermore, we verify the performance of the proposed identification method and evacuation strategy by simulating on VISSIM. The research outcome shows that the proposed algorithm is correct and effective.