Assessment of the Impact of the Francis Scott Key Bridge Collapse on Regional Traffic

The collapse of the Francis Scott Key (FSK) Bridge in Baltimore, Maryland, on March 26, 2024, killed six people, severed a major interstate highway, and closed the Port of Baltimore for 78 days. The authors of this paper, in collaboration with the Bureau of Transportation Statistics and the Maryland Department of Transportation State Highway Administration (MDOT-SHA), were tasked with monitoring the impact of the FSK Bridge collapse on the regional road network. To do so, the study leveraged multiple data sources provided by MDOT including commercial motor vehicle (CMV) anonymized trajectory data, traffic volumes from count stations and virtual weigh stations, travel times from vehicle probe data, and incident data extracted from the Center for Advanced Transportation Technology Laboratory’s Regional Integrated Transportation Information System. The study looked at both short-term (2 weeks before and after the bridge collapse) and long-term (3 months after the bridge collapse compared with the same dates in 2023) impacts of the bridge collapse on CMV travel patterns, traffic volumes, travel times, travel time reliability, and incidents. The analysis revealed significant changes across all analysis metrics. Key findings include long-term increases in the average, median, and 95th percentile travel times for all alternative routes, indicating increased congestion and diminished travel time reliability. In addition, the incident count increased, especially outside of peak hours, where an increase of 60% to 172% was observed across different alternative routes.