An iterative optimization model for hazardous materials transport with demand changes

Hazardous materials transportation network optimization can help to decrease accident rates and improve transport efficiency. An iterative optimization model of the transport network is established which considers characteristics of both government and enterprises. The first aim of government is to minimize transport risk, while enterprises want transport cost to be the lowest possible, so the top-level objective of this model is to minimize transport network risk and the low-level objective is to minimize total cost. When demand is determined, the total cost obtained from low-level model is added to top-level as constraints to determine the optimal transport network. When demand changes, we introduce safety coefficient to solve this model. A small transport network is used to verify this model and algorithm, and the results show that the proposed methods are feasible and stable.