Operations research models for global route planning in hazardous material transportation

The chapter introduces the master routing problem and its variants in hazmat transportation. Global routing is the main focus. Different objectives are discussed taking into account the roles played by the actors involved in the decision process, i.e., carriers and governmental authorities. Emphasis is in particular given to network design and toll setting in such issues. The network design problem consists in defining either the subnetwork of the entire transportation network onto which hazmat flow can be routed with minimum risk, or the capacities allowed for such a flow on each network arc to achieve the same objective. Network design involves also the successive carrier decision about the minimum cost paths to be used on the designed network. Therefore it is a biobjective problem with two decision makers, and, in the literature, a bilevel optimization approach is often used. Toll setting is a recent topic of research in hazmat transportation: the idea is to use a toll policy to discourage carriers from overloading portions of the network with the consequent increase of the risk exposure on the population involved. Approaches based on bilevel optimization and game theory are discussed and compared.