Skanska has signed a contract with the Washington State Department of Transportation to replace the Portage Bay Bridge in Seattle, Washington, USA.

The US$1.4 billion design-and-build endeavor entails constructing two parallel bridges and installing a landscaped “lid” over SR 520, a major roadway crossing the bay between 10th Avenue East and Delmar Drive East. This project is part of a broader initiative to reconstruct the SR 520 corridor stretching from Bellevue to Seattle, covering approximately 17 km. The aim is to replace the existing Portage Bay Bridge to meet current seismic resilience standards and introduce a lidded segment at East Roanoke Street. Upgrades include modernized roadways, designated carpool and public transit lanes, and the creation of a landscaped open space lid above the highway. This development will establish a new multimodal connection by extending the regional shared-use path, facilitating biking or walking across Portage Bay to the new Roanoke Lid. The project seeks to enhance safety during travel across the bay, improve mobility, and expand connections to Seattle’s non-motorized trail network.

Aecom, a US-based engineering firm, will lead the project's design, with construction slated to commence in August 2024 and anticipated completion by 2031.