Abstract
Transportation networks are an indispensable component of everyday life in modern society. Disruption to the networks can make peoplesâ?? daily lives extremely difficult as well as seriously cripple economic productivity. In this paper, the authors develop network-based accessibility measures for assessing vulnerability of degradable transportation networks. The accessibility-based vulnerability measures explicitly consider the interaction between the disrupted network and the multi-dimensional travel responses of the network users. To model different dimensions of travel behavioral responses, a combined travel demand model formulated as a variational inequality problem is adopted to estimate the utility-based accessibility measure that is consistent with random utility theory. Numerical examples are conducted to demonstrate the feasibility of the proposed network-based accessibility measures for assessing vulnerability of degradable transportation networks. The results indicate that the accessibility measures derived from the combined travel demand model are capable of measuring the consequences of both demand and supply changes in the network and have the flexibility to reflect the effects of different travel choice dimensions on the network vulnerability.