A time-dependent flow model for Hazmat transportation routing

A lot of researches have been achieved on Hazmat transportation routing problem in order to take into both transportation out-of-pocket expenses and risk-related costs which are viewed as static. In this work, we consider the following hazmat transportation problem: a given set of hazmat shipments has to be shipped over a road transportation network in order to transport a given amount of hazardous materials from specific origin points to specific destination points and guarantee the minimum distance between Hazmat shipments is satisfied at any time and provide a time-dependent programming formulation represents the decisions for hazmat transportation routing problem. Then we transform the problem into a set of time-dependent shortest path problems for each truck that are relatively easy to solve when isolated. We exploit this characteristic to propose a method and heuristic that solves the shortest path problems iteratively on modified/restricted graphs. The proposed time-dependent model and heuristic algorithm are experimented on real scenarios of a regional network.