Two-step Solving Algorithm for Hazmat Transportation Routing and Dispatch Problem

This paper focus on the multi-objective routing and dispatch problem for a given hazardous materials shipment with multiple time windows and time varying attributes. Section 1 consists of background and purpose of the research. Section 2 proposes a mathematical model for this problem by introducing the punishing functions to convert time windows into penalty variables of model. Section 3 develops a two-step solving algorithm for model, of which the first step is to identify the non-dominated paths with specific dispatch time based on the improved dynamic programming method, and the second step is to choose the optimal alternatives from non-dominated paths by the application of the grey correlation analysis method. Section 4 carries out a case study to test the methodology proposed in the paper. The results show that the model and the two-step algorithm can effectively solve road hazardous materials transportation routing and dispatch problem.