A load and time-dependent hazardous materials distribution problem in urban areas
研究了危险品配送中同时最小化行驶距离和运输风险的路径与调度问题，提出了考虑载重和速度的新风险度量，并用改进的NSGA-II算法求解。
The objective of this paper is to model and solve the hazardous materials distribution problem in which a set of orders is serviced by a heterogeneous fleet of tank trucks. The objective of the problem is to determine the delivery routes of the trucks so that all the orders are serviced at the minimum traversed distance and transportation risk. A new transportation risk measure is proposed, which takes into account: (i) the population exposed within a load-dependent, impacted area around the truck, and (ii) the travel speed of the vehicle. Moreover, the proposed problem incorporates the effect of the scheduling of the loading operations performed at the depot into the routing problem. The proposed problem is modeled by a bi-objective vehicle routing and scheduling problem, which apart from determining delivery routes, deals simultaneously with the scheduling of the loading operations at the depot. To address the bi-objective routing and scheduling problem, we have developed an NSGA-II algorithm, known as a non-dominated sorting genetic algorithm, with various novel features. The results of the performed experiments indicate that the proposed risk measure substantially reduces the duration that the population stays under the risk of a HazMat shipment.