Hazardous materials collection with multiple-product loading

We present a new hazardous material (HAZMAT) collection problem in which various industrial HAZMAT are transported using a homogeneous capacitated truck fleet. Different materials have different risk levels in terms of the size of exposed population. A truck can simultaneously carry different materials. The size of the population exposed to a loaded truck increases if a higher risk material is added to the load. We minimize the total exposed population and the total transportation cost. We present a case study in the City of Santiago in Chile to show practical application of our proposed approach.