Research On The Assessment Method For The Vulnerability Of Transportation Networks

The assessment of transportation networks’ vulnerability is an important way toapproach whether it runs steadily and safely. The concept of transportation networks’vulnerability proposed by scholars at home and abroad is collected. Based on them, thevulnerability concept of transportation networks is presented, which is accepted by mostscholars and regarded as a characteristic related to failure probability and failureconsequence. Finally this paper proposes a systematic assessment method of thevulnerability of nodes, edges, sub-networks and the whole transportation network.This paper proposes the concept of importance degree, in terms of which, theheadstream of vulnerability is distinguished from an transportation network. The trafficdemand and the traffic supply is regarded as two stochastic variables which areindependent to each other and are true of normal school, a calculation model of roadfailure probability can be derived based on reliability theory and probability theory. Anew assessment method of road failure consequence is proposed based on UE modelwhich considers the spread of congestion in the transportation network according to asubsection impedance function. This method is mainly to assess the vulnerability of thenetwork’s structure. Based on the traditional assessment model of risk, this paperconsiders the product of failure probability and failure consequence as the calculationmodel of vulnerability. As example shows, it is different to sort by vulnerability degreefrom by importance degree or only an assessment index. The vulnerability is thecomposite reflection of failure probability and failure consequence. Generally speaking,nodes and edges with large vulnerability degree have high failure probability and seriousfailure consequence. What’s more, the vulnerability of nodes is generally larger thanedges.The assessment method of this paper effectively gets over the disadvantage of the assessment from a single angle and improves the precision of assessment and analysis.This method also can make an accurate positioning of the part which has high failureprobability and high failure consequence. Therefore, the assessment method is able toguide the transportation planning and traffic management.