Using an AHP-ISM Based Method to Study the Vulnerability Factors of Urban Rail Transit System

As a sustainable means of public transportation, urban rail transit system undergoes rapid expansion in China. How to provide a safe and reliable service has been the subject of growing attention in this context. However, such work is challenging because rail transit systems are quite vulnerable and influenced by a set of interacting factors. Studying these vulnerability factors will contribute significantly to the operation of rail transit system. From this perspective, this paper made an exploration of the vulnerability factors based on an integrated method consisting of AHP (Analytical Hierarchy Process) and ISM (Interpretative Structural Modeling). Based on literature review, 21 vulnerability factors were identified. Subsequently, expert elicitation was employed to ascertain the importance of each factor and the interrelations among them. The results suggest that management and individual factors have the highest importance weights and the interrelations among vulnerability factors could be expressed as a five-layer structure, in which management factors were inclined to be at the lower level. The research provides valuable information for decision makers to take proactive strategies and reinforcement policies to guarantee safety operation of urban rail transit system and ensure urban public safety, which could promote the sustainable development of cities.