Integration of Safety in the Optimization of Transporting Hazardous Materials

The development of fully integrated supply chain networks has drawn much attention due to industrial integration and globalization. Inter-plant transportation of chemicals plays a central role in enabling efficient supply chains and eco-industrial parks. The transported materials often include hazardous material (HazMat) for which safety is a major concern. This paper presents a HazMat transportation model that considers both economic and safety objectives. The study uses historical incident data for HazMat from the U.S Department of Transportation (USDOT) to quantify the transportation risk, and the epsilon-constraint method is then applied to integrate risk into the optimization framework. A case study was conducted for methanol transportation using both highway and railroad. The results of this study illustrate a Pareto optimal curve that shows the trade-off between transportation cost and risk. By solving the optimization problem, the optimum transportation cost at each discretized risk value can be determined, and the two objectives can be correlated for further decision-making. The HazMat transportation model provides a flexible framework to integrate more factors into the traditional transportation or material allocation problem in the future.