Risk-Based Asset Management Framework for Subway Systems

The 2017 report card for America's infrastructure assigned a grade D to transit systems indicating they are in a poor condition with strong risk of failure. A possible solution proposed is adopting a comprehensive asset management system to maximize investments in light of the fund scarcity dilemma. This research develops a risk-based asset management framework for subway networks. A generic subway hierarchy is proposed, and risk is assessed using three submodels: failure index, consequences of failure, and criticality index (CI). The Failure Index is predicted using inspection reports and the Weibull reliability function. Consequences of failure are assessed based on seven criteria along financial, social, and, operational perspectives. The CI is introduced to assess the functional importance of a station in its location using seven attributes along three main criteria. The Fuzzy Analytical Network Process is employed to analyze experts' knowledge used in the two functional submodels. The real case study assessment indicates two stations with high risk indices showing the necessity of an intervention action. This research presents a basis for evaluating subway infrastructure on a structural and functional basis. It assists authorities to derive an informed rehabilitation decision using a generic and consistent framework.