The National Transportation Safety Board has issued recommendations for vulnerability assessments on 68 bridges across the United States, including the Mackinac Bridge and several bridges in the Philadelphia area, to evaluate the potential risk of collapse due to vessel collisions. 6abc reports that the National Transportation Safety Board's call to action follows the tragic incident last year where the Francis Scott Key Bridge in Baltimore collapsed after a containership, the Dali, struck a support, resulting in the loss of six construction workers' lives.
The list of vulnerable bridges was spurred by the fact that, had the Maryland Transportation Authority conducted a proper assessment, they might have been able to prevent to take measures against the Key Bridge collapse. The National Transportation Safety Board found that the Key Bridge was almost 30 times over the acceptable risk threshold for bridges deemed critical or essential, as CBS News Detroit states. The Mackinac Bridge, opened in 1957, is among these bridges and is significant as it connects Michigan’s lower and upper peninsulas, spanning the Straits of Mackinac.
This evaluation does not imply that a bridge is certain to collapse, but rather highlights a need for proactive measures. "Today's report does not suggest that the 68 bridges are certain to collapse," the National Transportation Safety Board specified, as per 6abc. They are urging the respective bridge owners, comprising 30 different entities, to investigate if these structures exceed the American Association of State Highway and Transportation Officials' acceptable level of risk and, if so, to develop a risk reduction strategy.
In contrast to the Key Bridge, Philadelphia-area bridges such as the Delaware River Turnpike Bridge and the Walt Whitman Bridge come with a significant preventative measure—the installation of "dolphins," structures designed to prevent ships from striking bridge piers. "All of our bridges have protection systems in place to prevent ships from striking them," said John Hanson, CEO of The Delaware River Port Authority, in a statement obtained by 6abc. Among the entities receiving recommendations for assessment by the National Transportation Safety Board are the Mackinac Bridge Authority and the Delaware River Port Authority, which oversees critical infrastructure in the transportation networks of their respective regions.
