Jacobs to oversee initial design phase for Sound Transit's West Seattle Link Extension construction project
West Seattle Link Extension: A New Era of Affordable Housing and Improved Transit Connectivity
Seattle is set to witness a significant transformation with the West Seattle Link Extension (WSLE), a major light rail transit project led by Sound Transit. The $6.7 to $7.1 billion project, designed to offer more reliable light-rail service within Seattle, is scheduled to begin service in 2032.
The WSLE covers a 4.1-mile corridor connecting neighborhoods through four new stations at SODO, Delridge, Avalon, and Alaska Junction. The project, approved by voters in 2016 as part of the Sound Transit 3 (ST3) plan, features elevated tunnels and surface routes.
Jacobs, a leading design firm, has been chosen to lead Phase 1 of the WSLE project by Sound Transit. Jacobs has delivered approximately 30 miles of light-rail system expansions for Sound Transit, making them an ideal choice for this significant development.
The planning phase for the WSLE began in 2017. In April 2025, the Federal Transit Administration issued a Record of Decision approving the project to advance to design. Construction and testing are scheduled to start in 2027.
The WSLE is split into four segments: SODO, Duwamish, Delridge, and West Seattle Junction. The SODO segment will include new station platforms with a staggered configuration and use a mix of at-grade, retained-cut, and elevated guideways up to 20 feet high. The Duwamish segment will cross the West Waterway on an elevated light-rail-only bridge and connect to an operations and maintenance facility.
The WSLE is expected to serve over 24,000 daily riders and improve bus-rail transfers and station access. It is designed to reduce travel time from Alaska Junction to Westlake station by 50% at peak times, down to about 16 minutes once the Ballard Link Extension is complete.
The new development near stations will include retail opportunities, making it a gateway to the community. The project is also intended to boost connectivity within the city of Seattle, offering commuters an alternative to the West Seattle Bridge during periods of peak demand.
The West Seattle Link Extension will add a new bridge, tunnel, and four stations to Seattle's transportation infrastructure, aiming to expand Seattle's light-rail network. The project is part of Sound Transit's overall efforts to expand Seattle's public transportation system.
Moreover, the WSLE focuses on affordable housing. The new developments near stations will provide housing options that are accessible and affordable for Seattle residents.
The Seattle City Council is taking steps to streamline permitting to keep the project on track. Led by Mayor Bruce Harrell, the City of Seattle is implementing measures to accelerate construction and reduce delays.
In summary, the West Seattle Link Extension is a major infrastructure project in the design phase as of mid-2025, with construction beginning in 2027 and service planned for 2032. It aims to improve transit connectivity in Seattle’s West Seattle area with new stations, guideways, and operational facilities, managed by Sound Transit with Jacobs as the designer. The project also focuses on affordable housing and will contribute to improved mobility within Seattle.
- The West Seattle Link Extension, a significant project in the infrastructure sector, is set to enhance Seattle's financial landscape by facilitating improved transportation and offering an alternate route during periods of peak demand for those commuting across the West Seattle Bridge.
- The light rail industry in Seattle is poised for expansion with the West Seattle Link Extension, a project that not only addresses transportation needs but also prioritizes affordable housing by providing accessible and affordable housing options near the new stations.
