Research On The Evaluating Index For The Vulnerability Of Transportation Network

The urban traffic network which keeps getting complex with the city’s expanding is animportant basis of the development of the urban society and economy. In this process, theweakness in standing the abnormal events of the urban traffic network begin to be exposed,which is the concrete manifestation of the vulnerability. The urban traffic networkvulnerability has been a hot issue in current traffic network researches.In recent years, many achievements have been gained in traffic network study, but thereare still a lot of deficiencies. The most serious deficiency is that most researchers assesstraffic network from a single side, which can only reflect the characteristic of the trafficnetwork from one side. However, the traffic network vulnerability reflects in many sides,such as topological structure, running state, etc. consequently, the vulnerability assessingbased on single index can’t reflect the real characteristics of the traffic networkcomprehensively and accurately.In consideration of the deficiency in the traffic network vulnerability assessing, thisthesis establishes an assessing index system of traffic network vulnerability whichcontains different indices and every individual index has a priority by means of analyzingthe common used vulnerability assessing indices, then verifies the validity and advantageof the index system through a practical traffic network of Changsha.In order to establish the vulnerability index system, the cardinal works in the thesis aredescribed as follows:1. The definitions of cut link and no-cut link are redefined. This thesis redefines cut linkand no-cut link on basis of complexity network theory and the analysis of the transmissionand influence of traffic congestion to make them reflect the transmission and influenceof traffic congestion in the traffic network.2. The total travel demand, travel demand structure, cascading failure condition in traffic network vulnerability assessing are analyzed. This thesis analyzes the influencemechanism of the total travel demand, travel demand structure, cascading failure conditionin the traffic network vulnerability assessing through a series of controlled trial.3. The assessing index system of traffic network vulnerability is established. This thesisestablishes an assessing index system of traffic network vulnerability on basis of thedefinition of the cut link and no-cut link to make them reflect multi-aspect characteristicsof traffic network vulnerability. Through setting priority in indexes, this thesis solves thedeficiency that the indices cannot be compared with each other when assessing the trafficnetwork vulnerability by different indices. At last, this thesis verified the validity andadvantage of the index system through a practical traffic network.