Modeling the effects of a transportation security incident on the commercial transportation system

Abstract

We develop a modeling tool to represent freight container flows and the potential changes in cost of those flows inflicted on the U.S. commercial transportation system by a Transportation Security Incident (TSI). Our model includes available data on container movements, origin-destination (O-D) matrices for international container flows entering or leaving the U.S., and development of an attacker-defender model to determine best contingency plans after a TSI. We design a multi-commodity network flow model, representing flows between foreign countries and North American ports, the modal volumes into and out of each port, and volumes between each port and the 84 U.S. Transportation Analysis Zones. Each O-D flow is a commodity with a specified origin and destination. Subject to constraints on total flow volume over the arcs, these commodities flow through the network at minimum cost. The model finds paths through the network for containers to minimize their total transportation costs, and identifies a set of the most-critical infrastructure components of the commercial container transportation system that could be affected by a transportation security incident. This tool can help decision makers identify critical components to improve security and capacity on existing commercial transportation infrastructure in an environment with limited available funding.