Abstract: In this study, the traffic congestion of the ring-radial road network is investigated considering the traffic demand and road network topology. Based on the OD data analysis of taxi passengers from several cities in China, the travel distance distribution characteristics of the taxi users are studied; further, a universal traffic demand generation model is established based on the OD distribution. Thus, the traffic congestion in case of two typical traffic network structures, i.e., the regular grid and ring-radial road networks, are studied under the specified demand distributions. The results denote that the ring-radial road network topology can effectively reduce the network congestion time and reduce the transportation cost under the traffic demand that satisfies the specific OD Euclidean distance distribution.

Key words: traffic network equilibrium assignment, traffic demand distribution;topological structure;traffic congestion