Assessing and managing risk of terrorism to Virginia's interdependent transportation systems.

This study expanded on the scope of two previous contract studies for the Virginia Transportation Research Council completed in March 2002 and April 2003. The objective was to develop a methodology for the assessment and management of the risk of terrorism to Virginia's interdependent transportation infrastructure. As the economy of the Commonwealth continues to grow and expand, the importance of the transportation system increases. Many economic sectors use the transportation system either for transport or commuting purposes. These sectors continue to become more and more interdependent with the transportation system. A disruption to the transportation system, such as a terrorist attack, will propagate to other sectors. This study sought to assess the risk due to interdependency and develop risk management options to mitigate that risk. Three levels of analysis were conducted: statewide, regional, and asset-specific. At the statewide level, the impact of a terrorist act was assessed using the Inoperability Input-Output Model (IIM). The outcome was measured in two metrics: economic losses and percentage of inoperability. The top affected sectors were identified, and risk management options were recommended. The regional level risk assessment made use of publicly available databases to structure a perturbation. The perturbation was then analyzed using the IIM, and the resulting economic loss and inoperability were computed. For the asset-specific level, three assets were selected: the Midtown Tunnel, I-81, and Sentara Norfolk General Hospital. The risk of terrorism was assessed using publicly available databases and interviews with related experts. Risk management options were developed to mitigate the risks. A computer tool was developed to facilitate the analysis process for other Virginia Department of Transportation assets.