Johns Hopkins Researchers Assess Risks to Aging U.S. Bridges

Johns Hopkins University engineers have launched an urgent study to assess the risk of ship collisions with major U.S. bridges, spurred by the recent collapse of the Francis Scott Key Bridge in Baltimore. The team, led by risk assessment expert Michael Shields, is investigating whether current bridge designs can withstand the pressures of modern maritime traffic, particularly from massive cargo vessels.

“We need to know now, not five or ten years from now, whether there is an outsized risk to bridges across the country,” Shields told the Johns Hopkins website. “The Key Bridge collapse was a wake-up call.”

The Francis Scott Key Bridge disaster occurred on March 26, when the containership Dali lost power and crashed into one of the bridge's support columns, resulting in the deaths of six roadwork crew members. The collapse has highlighted the vulnerabilities of older bridges that were not designed to handle the increased size and frequency of modern shipping vessels.

Funded by a National Science Foundation Rapid Response Research grant, the Johns Hopkins team, made up of students and faculty, aims to modernize risk prediction models. These models will use global shipping data to assess the probability of a ship deviating from its course and striking a bridge. The study will focus on large bridges near major ports of entry across the United States.

“Preliminary findings already challenge prevailing assumptions,” said team member Rachel Sangree, a structural engineer and former bridge inspector. “The U.S. has seen 17 incidents of major bridge collapse between 1960 and 2011. Many of our bridges simply weren't built to withstand the pressures of today's maritime landscape.”

The National Transportation Safety Board (NTSB) is also investigating the Key Bridge collapse. Their preliminary report indicated that the Dali bypassed a protective concrete piling, known as a dolphin, before striking the bridge. The NTSB has urged bridge owners to enhance pier protection to prevent similar incidents. The Chesapeake Bay Bridge near Annapolis is among the structures under scrutiny for potential upgrades.

The Johns Hopkins study, expected to take about a year, aims to provide policymakers with data to prioritize infrastructure improvements. Shields emphasized the importance of accurate risk assessment to ensure the sustainability of critical infrastructure, with the cost to rebuild the Key Bridge estimated between $1.7 billion and $1.9 billion.