Network Interdiction Methods and Approximations in a Hazmat Transportation Setting

The United States transportation system is an extensive and integrated component in the eight key infrastructures upon which the livelihood of the U.S. is dependent (Department of Homeland Security 2009). The accessibility and mobility enabled through open use of the transportation system is a vital and necessary freedom which contributes to the fluidity of the American environment. The transportation system is expansive and heavily utilized with an average of over 2 billion daily vehicle-miles of travel (nearly twice as much travel since the early 1980s) on the roughly 4 million miles of paved roadway, nearly 47,000 miles of Interstate highway, 600,000 bridges and 366 U.S. highway tunnels over 100 m (Texas Transportation Institute 2011; Transportation Security 2012). Travelers and shippers may also choose to utilize more than 300,000 miles of freight rail, nearly 10,000 miles of urban and commuter rail systems, or connect between 500 commercial-service and 14,000 general aviation airports (Transportation Research 2002).