The Sound Transit Board selected the route and station locations for the West Seattle Link Extension. This action authorizes the project to move forward into the final design phase and construction is expected to begin in 2027.

This also established the project definition for the NEPA Record of Decision (ROD). When the ROD is issued, the federal environmental review process will be complete, and the project can proceed. This is expected to be completed in late 2024.

In conjunction with the publication of the Final EIS in September, Sound Transit updated the cost estimate for the West Seattle Link Extension to between $6.7 and $7.1 billion. In response to this significant increase the board passed Motion M2024-29 directing the agency to develop a workplan to improve the agency’s financial situation and move WSLE through design to inform a financially sound project. The workplan will include programmatic, financial, and project-level measures.

“Through the Board-directed work plan, our action today allows Sound Transit to use the design process to address cost pressures, reduce impacts, and prepare projects for construction, fulfilling our promise to the voters,” said Sound Transit Board Chair and King County Executive Dow Constantine. “I want to thank everyone who has engaged with us throughout the planning process to-date.”

Making Transit Improvements

The West Seattle Link Extension was approved by voters in 2016 as part of the ST3 plan. The project will extend light rail 4.1 miles and serve four new stations at SODO, Delridge, Avalon, and the Alaska Junction.

Trips between Alaska Junction and Westlake stations will take only 16 minutes during peak hours, a 50% reduction from current travel times.

The extension will improve overall transit service frequency, reliability, and capacity, facilitate redevelopment, and provide a travel alternative when the West Seattle Bridge is congested or unavailable.

“A safe, connected, and well-maintained transit system is a top priority for my administration, and Sound Transit 3 represents the largest infrastructure program in Seattle’s history. We must also match our ambitions with accountability,” said Sound Transit Board member and Seattle Mayor Bruce Harrell. “As a Board, our role is to ensure that construction impacts and rising costs do not overly burden community as we work to deliver these transformative projects. Today's approved action on the West Seattle Link Extension route and stations is a forward step in helping us meet our challenges and getting us closer to providing reliable transit for generations to come.”

Moving to Design

The final alignment selected by the board is the Final EIS Preferred Alternative.

The alignment incorporates refinements requested by the Sound Transit Board when it identified the preferred alternative in 2022. Working with community members, the City of Seattle, and King County, staff studied the project features to enhance station access, prioritize an integrated and well-designed transfer experience from buses to light rail, and address concerns over potential displacement of organizations servicing low-income and communities of color.

“Today’s action gives Sound Transit the green light to move forward on West Seattle Link Extension’s final design, to study ways to contain costs, and to work further on avoiding or mitigating the impacts of this major construction project in the neighborhoods it will serve,” said Sound Transit System Expansion Committee Chair and King County Councilmember Claudia Balducci. “We’ve worked hard to get to this point, and I remain committed to deliver the fast, frequent, and reliable transit we promised the voters as quickly and affordably as possible.”

The Board’s approved resolution included an amendment to move forward with the development and implementation of the workplan to improve the agency’s financial situation and move the West Seattle Link Extension through design. The amendment also directed the agency to continue working to reduce identified project impacts during the design phase and advancement of the workplan to achieve cost savings and minimize community impacts.

The agency will return to the Board in the future as the design progresses and to authorize construction dollars.