The MTI team has been working closely with MD local agencies to study and mitigate traffic impacts caused by the Key Bridge Collapse.

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Key Bridge Collapse Impact Study and Mitigation

The collapse of the Francis Scott Key Bridge in Baltimore, MD, on March 26, 2024, triggered by a collision with the MV Dali container ship, has brought about severe mobility and logistical disruptions. With no convenient alternate routes available, the incident has drastically affected around 34,000 daily commuters. The closure of the outer loop of I-695 up to Quarantine Road and the inner loop at MD 157 (Peninsula Expressway) has forced commuters to take lengthy detours via I-95 (Fort McHenry Tunnel) or I-895 (Baltimore Harbor Tunnel).

Mobility Impacts

Using large-scale traffic data and more than 46,000 vehicle trajectories, this study evaluates how mobility patterns evolved one year after the collapse. Results show that while travelers and transportation agencies have adapted, major bottlenecks remain—especially along I-95 and I-895 near the tunnel crossings—indicating that the regional transportation system has improved but has not yet returned to pre-collapse conditions.

                  Mid-Term Change of TTI in Baltimore Area During AM Peak                                                         Mid-Term Change of TTI in Baltimore Area During PM Peak

Key Findings

  • Persistent freeway congestion: Alternative routes through the Fort McHenry and Baltimore Harbor Tunnels continue to experience severe congestion. Even after one year, AM peak travel times through these bottlenecks remain approximately 50% higher than before the collapse.
  • Morning congestion has partially recovered: AM peak delays have eased as commuters adapted through schedule changes, telework, and route adjustments. However, tunnel approaches remain significant bottlenecks.
  • Evening congestion remains a major challenge: PM peak congestion has shown little recovery, with persistent delays caused by commuter demand, discretionary trips, and freight traffic shifting into later periods.
  • Local adaptation reduced some impacts: Improvements were observed on portions of I-695 where bridge-related traffic demand decreased, demonstrating how travel behavior changes can reshape network conditions after a major disruption.
  • Short trips were affected the most: Short commuter trips through the tunnel bottlenecks experienced the largest delays. PM peak short trips nearly doubled in duration and remained about 87% longer than pre-collapse levels one year later.

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