An integrated network/planar multiobjective model for routing and siting for hazardous materials and wastes

Dealing with hazardous materials and wastes has become a problem of major concern for countries throughout the world. This paper presents a model useful in making routing decisions, for either material or waste shipments, and siting decisions for waste treatment facilities. Risk, cost, and risk equity are considered jointly in a multiobjective framework. Costs are treated as link attributes while risks, from both transport and treatment, are zonal attributes, pertaining to nonoverlapping geographic areas spread out over the plane. Risks accrue within these zones, due to shipments crossing nearby links or wastes being processed, stored or disposed of at nearby treatment facilities. Total risk is the sum of the zonal risks. Equity is measured as the maximum zonal risk per unit population. Shippers will find the model useful in optimizing their logistic plans. Government agencies will find it helpful in determining how regulations should be set to obtain publicly desirable routing and siting patterns. The model is described in detail and applied in simplified form to an illustrative problem.