Road Traffic Network Vulnerability Assessment, Validation And Its Visualization Method

In recent years, with the deepened researches on the complex network theory,researchers of transportation science have been starting to study traffic network from anew perspective. The urban road network is the important carrier of traffic activities. Theevaluation and analysis of the road network vulnerability has become a hot topic recently.Road traffic network vulnerability could be referred as the susceptibility of considerablereduction of the network serviceability due to attacks or accidents resulting failures ofnetwork units. Road traffic network vulnerability is mainly influenced by three factors:network structure, failure unit and traffic flow state. Since the road traffic network isaffected by the rigid network structure and elastic traffic demand jointly, this paperredefine vulnerability dividedly as structural vulnerability and state vulnerability, and putforward the structural vulnerability-state vulnerability-comprehensive vulnerabilityprocess of vulnerability evaluation.The paper presents a method of abstraction for road traffic networks by usingdifferent topology types, and on this basis, discusses the complex network structureindexes for describing the structural vulnerability. With the discussion of the micromechanism, the calculation of indexes of the state vulnerability and the comprehensiveindexes is proposed. In this context, the method of road network vulnerabilityclassification is described which is referred to ordered sample analysis. According to thedynamic traffic assignment model, a traffic assignment mechanism in light of network unitfailure is presented, and so is the mathematical simulation model expression. Later, thetheoretical discussion of simulation evaluation system for road network vulnerability isproposed, and on this basis, the general idea of validation for the vulnerability evaluationby sampling analysis is illustrated. The paper also presents a visual system for vulnerability evaluation and validation.And through the methodology of visualization, the structure of the visual system is putforward which is framed by using professional traffic macroscopic analysis softwarecombined with the development language, whose process could be realized via COMinterpreter. The detailed steps for realization of different system modules are also proposed.Finally, an empirical study is presented using the road network of Chenzhou city. With themethod of vulnerability evaluation and analysis proposed and the visualization method,the road traffic network vulnerability evaluation and classification for Chenzhou city isrealized by the application of macroscopic traffic analysis software VISUM andprogramming language Python. The applicability of the visualization system is fullyconfirmed.