Spatiotemporal vulnerability analysis of railway systems with heterogeneous train flows

This paper proposes a comprehensive framework to analyze the spatiotemporal vulnerability of a railway system with heterogeneous train flows. The spatiotemporal vulnerability is assessed by the passengers' delay associated with the dynamic state of the railway system under a disruption, whose structure consists of a physical layer and a service layer. The physical layer is used to characterize the railway system's post-disruption state, including damaged components and their damage occurrence time and duration; while the service layer is used to capture time-related attributes of trains and passengers to estimate the passengers' delay. Based on these two layers, the spatiotemporal vulnerability of the railway system can be investigated for different disruptions. This study applies the proposed framework to Chinese Railway System and analyzes its spatiotemporal vulnerability under two types of disruptions: the individual station failure and the spatially localized failure. The findings of this study facilitate better design of system maintenance strategies and help mitigate system spatiotemporal vulnerability under various disruptions.