Assessing Urban Rail Transit Systems Vulnerability: Metrics vs. Interdiction Models

Assessing Protection Strategies for Urban Rail Transit Systems: A Case-Study on the Central London Underground

“…In this paper, we argue that an integrated approach based on fortification models is a more effective and accurate tool to allocate protection resources than a sequential approach based on vulnerability metrics, thus extending the work of [9]. To prove our claim, we consider the most recent measures recently proposed in the literature to assess rail transport systems' vulnerability, in addition to those identified in [9]. These include metrics belonging to the three aforementioned categories (i.e., connectivity, path length and flow) and also metrics for each combination of two out of three of these criteria.…”

“…The integrated approach deployed in this paper relies on a novel bi-level multi-criteria optimisation model, namely the Railway Fortification Problem (RFP). As reported in Section 2.2, previous models have typically focused only on one specific network feature (i.e., connectivity, path length, and flow) [9]. RFP combines these features, thus generating robust solutions with respect to multiple criteria.…”

“…Assessing the vulnerability of railway assets is paramount to allocate protection resources in a cost-efficient way ( [4][5][6][7][8]). To this end, Starita, Esposito Amideo, and Scaparra [9] provide two possible approaches aimed at identifying the most critical stations in a railway network (i.e., those whose disruption may affect the system functioning the most): one based on vulnerability metrics [10] and another one based on interdiction models [11]. Starita, Esposito Amideo, and Scaparra [9] group vulnerability metrics into three main categories: connectivity (node degree, network accessibility), path length (node vulnerability, node betweenness), and flow (passenger flow influence).…”

“…To this end, Starita, Esposito Amideo, and Scaparra [9] provide two possible approaches aimed at identifying the most critical stations in a railway network (i.e., those whose disruption may affect the system functioning the most): one based on vulnerability metrics [10] and another one based on interdiction models [11]. Starita, Esposito Amideo, and Scaparra [9] group vulnerability metrics into three main categories: connectivity (node degree, network accessibility), path length (node vulnerability, node betweenness), and flow (passenger flow influence). These metrics are used to obtain a ranking of the most critical stations of the Central London Tube network and are compared with the solutions of two interdiction models, namely the Path Interdiction Problem (PIP) and the Flow Interdiction Problem (FIP).…”

Aggregating Centrality Rankings: A Novel Approach to Detect Critical Infrastructure Vulnerabilities

“…Critical infrastructures are network-based systems hence, they are composed of nodes and edges. The literature shows that node criticality, which is the focus of this paper, can be addressed from different metric-based perspectives (e.g., degree, maximal flow, shortest path) [6][7][8][9][10]. However, each metric provides a specific insight while neglecting others.…”