Study on the Control of Traffic Congestion Based on Hierarchical Road Capacity

City traffic congestion control as the core problem in ITS, has been paid more and more attention. This article from the actual characteristics of spatial structure of city to divide different traffic levels is based on the flow of people and vehicles that two variables, which foundation underlies a new model of road capacity that describe and analysis the problem of road capacity from the needs of congestion control. Only in this way can we deepen the understanding over the dynamic traffic flow of city, so as to strengthen the purpose of city traffic network congestion and control.