I-95 over Cottman Avenue Emergency Repairs & Bridge Replacement

Pennsylvania Department of Transportation | Philadelphia, PA

A fiery truck crash led to a partial collapse of twin spans carrying I-95 traffic over Cottman Avenue. The northbound structure collapsed while the southbound structure was compromised and eventually demolished. Benesch has an extensive history working with the Pennsylvania Department of Transportation (PennDOT) on I-95 improvement projects. Within a few hours of the collapse, Benesch was in discussions with PennDOT and the contractor, and by the following morning, Benesch had been selected to help with the temporary solution and the future permanent replacement.

I-95 is one of the most important arteries on the East Coast. The section closed due to the collapsed structures connecting New York City to Philadelphia, and typically sees 160,000 vehicles each day. To get the critical corridor open, the project team developed a plan to construct a temporary roadway to carry three lanes of traffic in each direction.

A temporary retaining wall system was backfilled with Pennsylvania-made lightweight recycled foamed glass aggregate. The temporary roadway was paved on top of the aggregate and incorporated precast concrete barriers. During the development of the temporary solution, the team considered impacts to the permanent bridge replacement to ensure future staged construction would be feasible.

Benesch quickly developed a project plan, delegated tasks, and engaged 35 staff for this emergency effort. The experience came with intense pressure, but Benesch never backs away from a challenge. The project team relied on communication and collaboration with PennDOT and the contractor to implement the solution quickly.

Just 12 days after the collapse, the temporary roadway opened to traffic. Benesch continues to work on the permanent bridge replacement that will fully restore this critical corridor.

Practice Areas

Awards

  • 2024, National Recognition Award, American Council of Engineering Companies
  • 2024, Project of the Year - Special Project Award, American Society of Highway Engineers (ASHE) Delaware Valley Section
  • 2024, Project of the Year, Engineers' Society of Western Pennsylvania
  • 2024, Grand Conceptor Diamond Award, American Council of Engineering Companies - Pennsylvania
  • 2024, Outstanding Project Award, Pennsylvania Society of Professional Engineers - Delaware County Chapter
  • 2023, Remarkable Achievement Award, Associated Pennsylvania Constructors
  • 2023, Emergency Response Project of the Year, Engineers' Society of Western Pennsylvania

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photo showing placement of aggregate fill and construction of retaining walls during the emergency response to a bridge collapse on I-95

Efficient, Effective Materials

A major component of completing the reopening as quickly as possible was adapting the solution to incorporate products that were available for quick delivery to the project site, such as foamed glass aggregate, geogrid wire walls, and outside barriers.

Custom median barriers were required due to complex roadway geometry and were fabricated with round-the-clock effort. Constant communication and coordination between the Benesch Team, PennDOT, and the contractor ensured efficient construction and a safe solution for the traveling public.

Racing the Clock: Reopening I-95 in Just 12 Days

The project team reopened I-95 in just 12 days–a process that would normally take months. Critical design decisions for both the temporary and permanent bridge were made within days, and in some cases just a few hours, of the accident thanks to the successful collaboration of the team’s designers, contractor and PennDOT staff.

The northbound I-95 structure collapsed on June 11 after a tanker truck carrying gasoline lost control on the Cottman Avenue off-ramp. Within hours, Benesch was engaged as part of the emergency response to rebuild and reopen the bridge.
By June 15, temporary replacement plans including a conceptual rendering were delivered thanks to the dedicated teamwork of Benesch’s designers, PennDOT and the contractor.
aerial photo of temporary roadway built to replace a collapsed bridge on I-95 in Philadelphia
On June 23, just 12 days after the collapse, the roadway was reopened to traffic on a temporary structure as work continued on the permanent replacement.
aerial view of new beams being set on I-95 as traffic continues in both directions on outside lanes, with cranes placed in middle lanes

Building the Permanent Replacement

The Benesch Team started design work for the permanent bridge replacement in the days after the collapse. Critical staging limit decisions were made within hours of the collapse so the temporary roadway and permanent bridge replacement solutions could work together. Leveraging a design-build delivery method has allowed the team to tailor the updated steel bridge design for efficient fabrication and construction.

Construction of the first phase of the permanent bridge was completed in November of 2023. Once traffic was shifted to the permanent bridge, the temporary roadway was demolished, with some components transported to other sites for reuse. Construction of the second phase continues with an anticipated opening date in summer of 2024.

aerial view of new beams being set on I-95 as traffic continues in both directions on outside lanes, with cranes placed in middle lanes