The National Transportation Safety Board (NTSB) is harshly criticizing Maryland officials for failing to conduct a risk assessment of the Francis Scott Key Bridge before it collapsed a year ago and is recommending that 30 owners of 68 bridges across 19 states conduct a vulnerability assessment to determine the risk of bridge collapse from a vessel collision.
The agency indicated that had Maryland conducted such an assessment, it could have taken steps to reduce the risk of and possibly prevented last year’s tragic Key Bridge collapse in Baltimore. In its own assessment, NTSB found that the Key Bridge was considerably above the acceptable risk threshold for essential bridges.
The federal agency warned that many of the nation’s bridges may be above the acceptable level of risk, although it stopped short of suggesting they are in danger of imminent collapse.
The report is part of the ongoing investigation into the Key Bridge collapse. The NTSB found that the Key Bridge, which collapsed after being struck by the containership Dali on March 26, 2024, 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, or AASHTO.
Over the last year, the NTSB said it identified 68 bridges including the Key Bridge that were designed before 1991 when the AASHTO guidance was established and do not have a current vulnerability assessment using AASHTO’s calculation.
The NTSB is recommending that these 30 bridge owners evaluate whether the bridges are above the AASHTO acceptable level of risk and implement a risk reduction plan if their bridge has a risk level above the AASHTO threshold.
Since 1994, the Federal Highway Administration, or FHWA, has required new bridges be designed to minimize the risk of a catastrophic bridge collapse from a vessel collision, given the size, speed and other characteristics of vessels navigating the channel under the bridge. The Key Bridge was built before vulnerability assessments were required by FHWA.
Neither the FHWA nor AASHTO can require a bridge owner to complete a vulnerability assessment for a bridge designed before the release of the 1991 guidelines. The MDTA had not performed, nor was it required to perform a vulnerability analysis, NTSB noted.
Maryland Assessment
However, the NTSB concluded that had the Maryland Transportation Authority (MDTA) conducted a vulnerability assessment on the Key Bridge based on recent vessel traffic, MDTA would have learned that the bridge was above the AASHTO threshold of risk for catastrophic collapse from a vessel collision before the Dali collision occurred and MDTA would have had information to “proactively reduce the bridge’s risk of a collapse and loss of lives associated with a vessel collision with the bridge.”
NTSB chair Jennifer Homendy said during its investigation her agency asked Maryland for the data needed to conduct an assessment based on current traffic volume but MDTA was unable to provide the data. NTSB had to develop the data itself. She said MDTA had still not done a vulnerability assessment based on current data as of October.
