Vulnerability simulation and evaluation of urban metro operation system: A hybrid structural equation model with system dynamics approach

To effectively identify the influence factors of urban metro operation system (UMOS) vulnerability and research the dynamic evolution process of system vulnerability, ensuring the long-term safety of UMOS, a hybrid method integrating structural equation model (SEM) and system dynamic (SD) is proposed to evaluate the UMOS vulnerability. The vulnerability evaluation indexes system of UMOS is established by questionnaire design, which includes four dimensions of personnel, equipment, management and environment. The effectiveness of the method is verified by taking Wuhan metro system in China as an example. The results indicate that (1) The influence of personnel, equipment, management and environment factors on UMOS is 30.2 %, 27.6 %, 21.6% and 20.6%, respectively. (2) The passenger flow level and emergency rescue system level have the greatest influence on the vulnerability of UMOS via sensitivity analysis. (3) Extreme weather conditions have the greatest impact on the environment sub-system vulnerability, which in turn affects the UMOS. Hence, the proposed method herein can simulate the long-term vulnerability of the entire UMOS and formulate corresponding improvement measures, thereby achieving sustainable transportation development.