Sound Transit’s West Seattle Link Extension is officially moving forward, following final federal approval that allows the project to enter the design phase.
The 4.1-mile extension will bring light rail service from SODO to the Alaska Junction in West Seattle, adding new stations in the Delridge, Avalon, and Alaska Junction areas. Once complete, the line is expected to serve more than 24,000 riders each day and cut travel times from West Seattle to downtown Seattle in half.

Approved by voters in 2016 as part of the Sound Transit 3 (ST3) plan, the project has been in development since 2017. Over the past eight years, Sound Transit has worked closely with West Seattle residents, local agencies, and community groups to finalise the route and choose the best station locations. The final alignment was selected by the Sound Transit Board in October 2024.
The project has now received government approval through the Federal Transit Administration’s Record of Decision, completing the environmental review process.
The next phase of the project focuses on detailed engineering and design work. Sound Transit will be refining station layouts, track placement, and construction plans, while also identifying ways to keep the project financially sustainable and on schedule.
Construction is expected to begin later this decade, though exact dates have not yet been confirmed.