A month after an interstate bridge collapsed in Minnesota killing 13 people, the Virginia Department of Transportation (VDOT) placed a ban on public access to detailed Virginia bridge inspection reports. The reports often include detailed information and photographs of structural weak points for each bridge. The VDOT claimed that terrorists or criminals planning to carry out attacks on bridges could potentially exploit open access to this information.
State departments of transportation in the US have recently received a record high number of inquiries for bridge structural inspection reports. As a result, the Department of Homeland Security (DHS) sent out alerts to the Federal Highway Administration and state departments of transportation highlighting the potential danger of disseminating such technical details. Additionally, the alerts urged states to consult federal officials before clearing requests for structural or security related data.
Although the structural weak points uncovered in inspection reports would be concealed, the final sufficiency ratings are still available to the public. While the public is entitled to know which bridges are insufficient, outdated or potentially dangerous, knowing the exact location of bridge vulnerabilities is best kept as a classified detail. In addition to concealing sensitive structural details, DHS is also funding projects to strengthen some of the largest most vulnerable bridges in the US. Such planning and guarding of sensitive information will be useful in thwarting possible future attacks.
Blast Resistant Shield for Bridge Cables
Since the uncovering of a terrorist plot to cut the suspension cables on the Brooklyn Bridge in 2003, US officials have been attempting to develop strategies to improve bridge security (Source). DHS is designating funding to improve upon the durability for some of the nation’s largest cable-stayed bridges. The growing popularity of the cable-stayed bridge, with its inexpensive, longer and stronger design, has resulted in 24 states adopting this technique in bridge building.
However, some security experts worry that the cable design is potentially vulnerable to a terrorist attack. Specifically, experts highlight the inexpensive design of only utilizing one set of cables to connect to the bridge. Despite the overall strength of the design, only one set of cables could instead represent the bridge’s lone weak point that terrorists may look to exploit.
While most of the nation’s cable-stayed bridges have already been retrofitted with various forms of protective gear, DHS officials are looking to develop a new material to coat the bridge cables. Beginning in August 2007, DHS officials began working with the US Army Corp of Engineers to develop a coating that could protect the cables from various types of explosions. At Fort Knox, Kentucky, researchers are testing the effects of various types of explosions detonated near tightened bundles of steel cable. As researchers claim to be making progress, DHS has set a goal for the resistant shield coatings to be ready for use within one year.
Possible Surveillance Incident Highlights Threat
On September 10, 2007, New Jersey State Police were anonymously notified that a 25-year-old man was allegedly taking photographs of an I-80 bridge that spans the Delaware River gorge. A state trooper responded to the tip and found a man of Middle Eastern descent in a car with his wife and child. The police officer then reported the man’s identification to state and federal authorities and discovered that the man was a “person of interest” on a federal terror watch list. However, as police could not find a camera in the man’s possession or in the car, the man and his family were permitted to leave without charge. Authorities have not announced why the man was placed on the federal terror watch list (Source).
Infrastructure Remains a Likely Target
Following the bridge collapse in Minnesota, the incident in New Jersey highlights a potential scenario where terrorists could scout bridges for potential attacks. However, the recent moves by state transportation departments to secure sensitive structural information, as well as DHS efforts to fund bridge-strengthening projects could reduce the likelihood that an individual could carry out a successful large-scale bridge attack.