Protecting Our Nation's Bridges and Tunnels

Engineers Face New and Unexpected Challenges

Bridge being blown up

You are looking at a bridge when you notice a suspicious package. Is it a bomb or just something else? Regardless, are you prepared to handle the situation?

"The threat is real: attacks at choke points could be devastating."

Blue Ribbon Panel on Bridge and Tunnel Security

Subsequent to the terrorist attack of September 11, 2001, bridge and highway engineers faced new and largely unexpected challenges related to protecting the physical security of critical transportation assets against possible attacks. Though the 9/11 events targeted buildings of significance, an Al Qaeda terrorist training manual captured in England contains goals that included missions for "gathering information about the enemy and blasting and destroying bridges leading into and out of cities."¹ State Highway Agencies (SHAs) must now identify any "missing" gaps and seek "best practices" guides and innovative techniques to enhance the security of their critical assets. However, the SHAs do not often possess the required resources and expertise to develop such technical standards and innovative ways of reducing the structural impacts of terrorist threats.

"Thank you to all of you for the great job on this security assessment. It is one of the cornerstones for (our) highway infrastructure security effort. We appreciate your efforts in developing this study. It is an excellent demonstration of the professional work FHWA does."

Director of Infrastructure Security (location intentionally withheld)

In 2002, the Federal Highway Administration (FHWA) assembled the Engineering Assessment Team for Security in an effort to address this concern. The team is comprised of employees from the FHWA Resource Center, Headquarters, the Turner-Fairbank Highway Research Center, the Federal Lands Highway Division, and Division offices. The mission of the Team is to assess structures in order to reduce vulnerability, minimize damage, and facilitate recovery from terrorist attacks.

Two of the main activities that the Engineering Assessment Team has undertaken in support of its mission are to perform vulnerability assessments of critical structures and to provide security training to SHAs and other bridge owners.

Vulnerability Assessments

Vulnerability assessments are an intense investigation of the critical components of bridge and tunnel structures that considers the likelihood that a terrorist can get an explosive, or other threat, to the critical locations and cause catastrophic damage. This information can then be used to develop cost-effective, prioritized strategies to make these facilities more resilient to these threats. The Engineering Assessment Team has worked with five SHAs to assess their critical infrastructure by identifying vulnerable components and recommending mitigation measures to lessen the concern, plus there have been three project-specific reviews in other States. In addition, the team has provided expertise to the United States Coast Guard as they completed assessments of every port across the country.

"The Team from the Federal Highway Administration provided valuable insight into the challenges we face not only today, but in the future, as we prepare for design, and ongoing operation and maintenance of this critical transportation corridor infrastructure."

Fire Chief
(location intentionally withheld)

Training

The Engineering Assessment Team has developed a 1-day workshop on Bridge and Tunnel Security and it has been delivered six times since September 2004 and there are four other workshops requested. The goal of the workshop is to identify threats to bridges and tunnels, list vulnerable bridge and tunnel components, recommend mitigation measures to help protect the structures, and identify a method of risk assessment.

book icon In 2006, this workshop will be offered in two formats. One will be an abbreviated version of the current workshop for inspectors and maintenance personnel. This workshop will focus on identifying threats and locating vulnerable components on bridges and tunnels.

The second format will be extended to cover the material over 1½ days and is targeted towards engineers and other technical personnel. The additional time will be utilized to cover the risk-based method in more detail to prioritize mitigation measures for vulnerable components.

In 2002, the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) jointly established the FHWA/AASHTO Blue Ribbon Panel on Bridge and Tunnel Security, to provide guidance to bridge and tunnel owners in this important area.

The charge to the panel was as follows:
Develop short- and long-term strategies for improving the safety and security of the Nation's bridges and tunnels, and provide guidance to highway infrastructure owners/operators.

The panel's object was to apply its collective experience and knowledge about structural design, structural integrity, and environmental stress and strain to new ways of examining how critical bridges and tunnels can be protected against potential terrorist attacks.

Members:
Mr. James E. Roberts
Chair, IBSEN and Associates

Dr. John M. Kulicki
Vice-Chair, Modjeski & Masters

Mr. Dwight Beranek
U.S. Army Corps of Engineers

Mr. Joseph M. Englot
Port Authority of New York & New Jersey

Dr. John W. Fisher
Lehigh University

Mr. Henry Hungerbeeler
Missouri Department of Transportation

Dr. Jeremy Isenberg
Weidlinger Associates

Dr. Frieder Seible
University of California at San Diego

Mr. Kenneth E. Stinson
Peter Kiewit Sons, Inc.

Dr. Man Chung Tang
T.Y. Lin International

Mr. Kary Witt
Golden Gate Bridge Highway and
Transportation District

For more information, contact:
Steven L. Ernst
Safety and Security Engineer
Office of Bridge Technology
FHWA Headquarters
(202) 366-4619
steve.ernst@fhwa.dot.gov

Derrell Manceaux
Senior Structural Engineer
FHWA Structures Technical Service Team
(720) 963-3205
derrell.manceaux@fhwa.dot.gov¹ Recommendations for Bridge and Tunnel Security, prepared by the Blue Ribbon Panel on Bridge and Tunnel Security, Sept, 2003.