Risk Management and Design of Critical Bridges for Terrorist Attacks

In the aftermath of the September 11th tragedies, the vulnerability of the United Statesʹ transportation infrastructure to terrorist attack has gained national attention. In light of this vulnerability, various governmental agencies are looking into ways to improve the design of structures to better withstand extreme loadings. Until recently, little attention has been given to bridges which are critical to our economy and transportation network. This paper summarizes the results of ongoing research to investigate economical, unobtrusive, and effective methods to mitigate the risk of terrorist attacks against critical bridges. It outlines a recommended plan to reduce these threats through proven risk management techniques, lists possible cost-effective security measures, discusses blast effects on bridges, and provides structural design and retrofit guidelines. It also discusses ongoing research oriented towards the development of a performance-based design methodology. In using proper risk management techniques, transportation managers and bridge engineers can mitigate the risk of terrorist attacks against critical bridges to an acceptable level, while ensuring efficient use of limited resources.