The National Transportation Safety Board (NTSB) has recommended that 30 owners of 68 bridges across 19 states conduct vulnerability assessments to determine the risk of collapse from vessel collisions.
This recommendation stems from the ongoing investigation into the collapse of the Francis Scott Key Bridge in Baltimore, which occurred on March 26, 2024, after being struck by the containership Dali.
The NTSB's findings indicate that the Key Bridge was almost 30 times above the acceptable risk threshold for critical or essential bridges, according to guidance established by the American Association of State Highway and Transportation Officials (AASHTO).
The 68 bridges identified were designed before the establishment of AASHTO's guidance and lack current vulnerability assessments.
The NTSB recommends that bridge owners calculate the annual frequency of collapse using AASHTO’s Method II calculation and, if necessary, develop and implement comprehensive risk reduction plans.
Notable bridges identified for assessment include the Golden Gate Bridge in California and the Brooklyn Bridge in New York City. The NTSB emphasizes that this recommendation does not imply these bridges are certain to collapse but underscores the importance of proactive evaluations to mitigate potential risks.
In the case of the Francis Scott Key Bridge, the Maryland Transportation Authority had not conducted a vulnerability assessment based on recent vessel traffic. Such an assessment might have revealed the bridge's heightened risk and allowed for proactive measures to reduce the chance of collapse and associated loss of life.
The NTSB also recommends that the Federal Highway Administration, the U.S. Coast Guard, and the U.S. Army Corps of Engineers establish an interdisciplinary team to provide guidance and assistance to bridge owners in evaluating and reducing risks. This could involve infrastructure improvements or operational changes to enhance safety.
National Transportation Safety Board (NTSB) is an independent U.S. federal agency responsible for investigating civil transportation accidents and issuing safety recommendations to prevent future incidents.