Jacobs wins design role on US$7bn Seattle light rail extension

A render of Lynwood Station in the Seattle, Washington, metro area. Recently, the station opened as part of a railway extension project. (Image courtesy SoundTransit)

The project will connect Seattle’s SoDo neighbourhood with Alaska Junction in West Seattle via a new bridge, tunnel and four new stations. Sound Transit estimates the extension will reduce peak-hour travel times by up to 50% and serve more than 24,000 daily riders when service begins in 2032. In addition to serving as a transport link, the new corridor is expected to catalyse transit-oriented development near stations, including retail and affordable housing.

Sound Transit approved the final route in 2024, which includes a long-span cable-stayed bridge over the Duwamish Waterway and a tunnel segment under West Seattle. The full project forms part of the broader ST3 regional expansion programme.

Jacobs’ initial contract is valued at $24.8 million for phase-one design and validation. The company said the contract includes a 10% contingency bringing the total authorised value to $27.3 million. The scope includes refining design documents, validating technical assumptions, and supporting early permitting and right-of-way planning.

“Transportation infrastructure enhances mobility and provides vital economic growth and community opportunities,” said Ron Williams, executive vice president at Jacobs. “The West Seattle Link Extension will serve as a gateway to the community, with streetscapes and public spaces that resonate with residents.”

Major construction is expected to start in 2027, following completion of final design and environmental approvals. 

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