A multidimensional quantitative risk assessment framework for dense areas of stay points for urban HazMat vehicles

Vehicles with Hazardous Materials (HazMat) are one of important factors causing safety risk in urban transportation system. Currently, the study of HazMat transport risk is mainly focused on the transport route where the vehicles are on the move. However, vehicular dwelling states such as loading and unloading, refueling, maintenance and resting constitute the vast majority of the time spent on HazMat logistics activities. The study attempts to develop a multidimensional quantitative risk assessment framework for HazMat vehicles in dense areas of stay points. The framework includes four indicators, i.e., direct damage risk, rescue accessibility and capacity, evacuation vulnerability, and environmental vulnerability, and adopts a comprehensive assessment model based on entropy weight TOPSIS method to evaluate the cumulative risk of HazMat vehicles in dense areas of stay points. Subsequently, this study conducted a case study based on HazMat vehicle trajectory data from Chengdu, China and visualizes the spatial distribution of different risk levels with SAFETI simulation and GIS technology. The study findings can serve as a reference for emergency management to develop preventive measures to eliminate hidden risks of HazMat vehicular dwelling states.