SEATTLE — The Washington State Department of Transportation (WSDOT) announced its design and construction partner to replace Seattle’s Portage Bay Bridge in a $1.4 billion project.
Skanska has been selected to design and build two new parallel bridges as part of the final improvements to the SR 520 corridor.
"That bridge is supported by hollow columns and so it's vulnerable in an earthquake," said Omar Jepperson, the WSDOT Program Administrator for the 520 Program. "So we will be replacing the current bridge with two new seismically resilient structures across Portage Bay."
The bridge is the final stretch of SR 520 that connects Montlake to Interstate 5 over Portage Bay. The project will also extend the bicycle and pedestrian trail. It will also create a three-acre recreational landscape lid over SR 520 between 10th Avenue East and Delmar Drive East in north Capitol Hill.
“We are proud to partner with the Washington State Department of Transportation to address these critical infrastructure needs at the West end of the SR 520 Corridor where it connects to I-5,” said James Bailey, executive vice president of Skanska USA Civil’s West Coast operations. “Our work to replace the Portage Bay Bridge is an important piece of broader improvements to the SR 520 corridor, one of the busiest across the Puget Sound region.”
Skanska will continue bridge operations during the construction, but said some closures will happen.
"We do have limited full closures of the bridge throughout the duration of the contract to make certain key tie-ins when we're making major traffic switches, but ultimately, our goal is to minimize those to the greatest extent possible," said Ryan Clayton, Skanska SVP of Western Business.
In 2022, WSDOT estimated this project would cost just over $800 million. The contract the department just agreed to with Skanska is nearly $1.4 billion.
Portage Bay Bridge renderings
Construction is scheduled to begin in August 2024 and is expected to be completed in 2031. This project is a part of the broader SR 520 improvement plan which the 2015 Connection Washington and 2022 Move Ahead Washington transportation legislative packages fund.
People who live near the Portage Bay Bridge said they hope noise and closures will be minimal.
"In the end, development has to happen, it's for a good reason," said Parimal Deshpande, who lives near the bridge. "But whatever they can do to reduce the inconvenience, like closures, would be helpful."
Skanska has worked with WSDOT and Sound Transit for a number of projects in the Seattle area.