Designing reliable transport networks: The multiple Network spoiler approach

Abstract

Transport networks are expected to remain highly reliable to ensure that users can experience smooth travel under both normal and abnormal traffic conditions. To design a reliable transport network properly it is necessary to take into account users reactions to incidents which cause disruption in different parts of the network. In order to design a reliable network to deal with such events, it is necessary to capture the users route choice behavior under degraded conditions. Furthermore, for practical reasons, it is imperative that any improvement scheme should give priority to links in the network which are most vulnerable to failure. Therefore in this paper we formulate a reliable continuous network design problem (RCNDP) in which the link flow is assigned to different routes considering the risk-taking behavior of the network users when confronted by network uncertainty. To capture this behavior, we pose the RCNDP under the multiple network spoiler formulation of risk-averse traffic assignment. The ability of this model to introduce higher capacity expansions on links vulnerable to failure and consider many operational states to cater for the worst-case scenarios of network reliability is demonstrated through two numerical studies.