A Case Study On The Complexity Of Urban Road Networks Based On The Dual Approach

Urban traffic network system is a typical giant complex system. Due to the complexity ofthe occurrence and distribution of urban passenger transporting, studies on urban transportnetwork need to consider various aspects of urban transport, such as the period ofdevelopment which a city is experiencing, the amount and structure of travel demand, theurban road network design method by which city network will be built to meet both currentand future traffic demands, etc.In recent years, researchs on the mechanism of the complexity of the urban trafficnetwork by using “complex network theory” have been progressing on many different levelsand aspects. For example, there have been many researchs on the formation and transmissioncomplextity of traffic congestion under different network topologies and simulations for realstructure of transportation network by which the network structure and operation pattern, evenits evolution law, can be studied systematically.For the existing complex network theory and related applied research, such as theEpidemic Spread model, Mass Media model, the Internet Packet Transmission model, theEnergy Transmission Network model, etc, they are all built from the actual network, and thuswill ensure that the simulation of complex network functions and the state of the evolutionmodel can be in line with the real network.In this paper, we proposed that the complexity analysis on urban transport system shouldbe divided into "five levels" considering both the existing research and the diversityinfluences of urban road and transport network. And during each research part, the real citynetwork and related data will be selected to use.In Chapter2, we choose Beijing, Guangzhou and Xi’an to research and verify theirtypical characteristics of complex networks in a larger city scale compared with existingresearch. And based on relevant complexcity network indicators, such as the network degree,network clustering coefficient,various efficiency index, the betweenness value and so on,some urban transport phenomena can be systematically analysed;In Chapter3, the abstract analytical errors of conditional dual method-ICN method are firstly analysed. Then combined with the road network properties, an improvement method ofthe ICN method,“RP-ICN method” is proposed and verrified in Xi’an;In Chapter4, according to the comprehensive need of urban road network systemsresearch and complex networks "Cascade Failure" theory ideas, a new reseach framework onthe complexcity of traffic congestion formation and evolution conbined with “urbantransportation macromodel” are proposed and verified in Xi an.Finally, we give a hierarchical analysis about the shortage about existing research and aninitial plan about the further research direction.