Abstract:

In order to effectively mitigate potential risks during the simultaneous transportation of hazardous materials by multiple vehicles, this study addressed the problem of simultaneous multi-vehicle transportation on distinct paths between 2 nodes within a hazardous materials transportation network. A method for calculating safe departure time intervals of vehicles was proposed to select paths and allocate vehicles. A mathematical model was established for simultaneously scheduling multiple vehicles to travel on different paths through path selection and vehicle allocation. A multiobjective optimization algorithm based on NSGA-II was designed for solving the proposed model. Using an example of transporting 10 hazardous material vehicles in an 8-node and 13-edge hazardous materials transportation network, the proposed method yielded 13 transportation schemes satisfying single-trip risk constraints and 15 transportation schemes satisfying total risk constraints. A comparative analysis was performed on transportation risk, distance, and time under different risk constraints. The results indicate that compared with the total risk constraints, the single-trip risk constraints are more stringent, which is suitable for road authorities to select safe transportation paths, while total risk constraints are suitable for carrier enterprises to make vehicle scheduling decisions.

Key words: hazardous materials transportation, vehicle scheduling, dissimilar paths, multi-objective optimization, non-dominated sorting genetic algorithm II(NSGA-II)