Risk Averse Routing of Hazardous Materials with Scheduled Delays

The term “risk-averse” in the routing of hazardous material is used for problems whose objective is to find the best and safest routes to connect various origin-destination (OD) pairs, taking into account the objective of minimizing either the maximum risk or the maximum exposure. In recent works, it has been demonstrated that for repeated shipments, where the accident probabilities over the various links in the network are unknown, the safest strategy is generally based on the use of a multiple routes for each OD pair. In this work, it is shown that further improvements can be made through scheduling the deliveries, that is, spreading the risk both in space and in time. The scheduling is particularly relevant when the vulnerability of the network is time-dependent.