Jacobs on July 17 reported being selected to provide design services for Sound Transit’s West Seattle Link Extension project in Washington State, which will add 4.1 miles of light rail from Seattle’s SODO neighborhood to West Seattle’s Alaska Junction neighborhood.
The alignment will include a new bridge, tunnel and four new stations (at SODO, Delridge, Avalon, and the Alaska Junction), according to Dallas, Tex.-based Jacobs, which provides advisory and consulting, feasibility, planning, design, and program and lifecycle management services. The firm will lead Phase 1 design and design validation for the extension (see map, top; download detailed map, below).
“Jacobs has delivered some of Puget Sound’s most critical transportation solutions for 70 years, including approximately 30 miles of light rail system expansions for Sound Transit,” Jacobs Executive Vice President Ron Williams said. “Transportation infrastructure enhances mobility and provides vital economic growth and community opportunities. The West Seattle Link Extension will serve as a gateway to the community, with streetscapes and public spaces that resonate with residents, while reducing travel times and improving access to jobs, education and services in the Seattle area.”
Background
The West Seattle light rail extension project was approved by voters in 2016 as part of ST3. In October 2024, the Sound Transit Board selected the route and station locations, following review of environmental documents and years of public feedback, according to Sound Transit. “This extension will reduce travel time from Alaska Junction to Westlake station by 50% at peak hours once the Ballard Link Extension is complete, taking only 16 minutes,” Sound Transit reported at that time. “The extension will improve transit service frequency, reliability, and capacity. Partnering on opportunities for development near stations, including affordable housing and other equitable transit-oriented development, will help support communities with direct access to transit. Additionally, WSLE [West Seattle Link Extension] will provide a travel alternative if the West Seattle Bridge is congested or closed for repairs.”
The Federal Transit Administration in April 2025 issued a Record of Decision approving the West Seattle Link Extension project and allowing it to advance to the design phase. That approval was the culmination of the planning phase that began in 2017, according to Sound Transit.
Construction and testing is scheduled to begin in 2027, with service starting in 2032. The project is expected to serve more than 24,000 riders per day, improving station access and the transfer experience from buses to light rail, according to Sound Transit.
Sound Transit last fall updated the cost estimate for the West Seattle Link Extension project, in conjunction with the publication of the Final EIS (Environmental Impact Statement). It was between $6.7 billion and $7.1 billion. In April, the transit agency reported that it is “continuing work to inform a financially sound West Seattle Link Extension project, including financial, programmatic and project-level measures to improve affordability.”
