One abstract method for the study of network transportation and its application in the traffic problem in the process of city expansion

One abstract method for the study of network transportation is proposed in this paper. By interpolating the properties of the edges that constitute network into the two leading parameters of the nodes, this method can abstract the configuration of real-life transportation networks without losing the influence of the distance and the capability of the physical facilities, which are essential parts of the transportation networks. With this method we can study network transportation from the local point of view and describe network congestion in detail, especially the dispersing of congestion. After applying this method, as an example, to the traffic problem in the process of city expansion, simulation results show that: the intuitions that with the same rate of particle generation and the same capacity and power, the smaller the network is the harder for the network to become congested; and the network will never be congested if the power of each node equals or is bigger than its capacity are incorrect. And the distance from one crossroad to another and the width of the roads can be designed properly, when designing a city, so as to enlarge the tolerance size of the city in the process of city expansion. This method may provide more appropriate guide for real-life traffic design of network transportation. PACS: 89.75.Hc, 89.20.Hh, 89.75.Fb, 05.10.-a