Mitigating the risk of hazardous materials transportation: A hierarchical approach

Hazardous Materials (hazmat), although dangerous, are an irreplaceable aspect of everyday life. This paper is presenting an integrated traffic control policy for hazmat transportation to alleviate the risks associated with hazmat carriers. The proposed policy is devised based on dual toll pricing (DTP) and network design (ND) policies, where a two-stage simulation-based optimization framework is proposed to enhance public safety in highways. This integrated policy is devised to concurrently restrict hazmat carriers from freeways in densely populated areas via the ND policy, and control regular as well as hazmat traffic in tollways via the DTP policy. In the optimization module, mixed integer linear programming is employed to find the optimum integrated policy, where a linear-relaxation technique based on the Karush-Kuhn-Tucker (KKT) optimality conditions is applied to reduce the mathematical model. The simulation module of the proposed framework uses agent-based simulation (ABS) modeling to evaluate the suggested policies realistically. The proposed framework has been demonstrated with real traffic data of San Antonio, Texas under AnyLogic® ABS platform. The experimental results reveal that the proposed framework is able to efficiently find the optimum integrated policy which in return, effectively reduces the risk of hazmat transportation in highways.