Sound Transit board mulls options for light rail line through south Federal Way

Original preferred route through south Federal Way is incompatible with Tribal cultural resources, agency says.

Sound Transit’s board of directors is sticking to part of a light rail route through Federal Way and has elected to study the rest to see if it can avoid harming Indian Tribe resources or building in poor soil.

The board also elected on March 23 to study new station options in Fife for the overall Tacoma Dome Link extension, which will one day connect residents and visitors from downtown Tacoma all the way to Northgate.

Sound Transit announced in early March that light rail access to the Tacoma Dome would likely be delayed to 2035, due to an additional array of options for routes and stations on the way there from downtown Federal Way.

By 2019, the agency had narrowed down the project to a single station in Fife and a single route through south Federal Way. But the Fife station location sits on a floodplain which, due to federal regulations, requires Sound Transit to now consider alternatives outside of the floodplain. And the originally preferred route through south Federal Way is incompatible with Tribal cultural resources, according to Sound Transit.

The board’s research in 2019 indicated the impacts to those resources could be minimized or avoided while keeping the preferred route. But further work and communication with the Tribes has shown that “impacts to these … resources are unavoidable with the preferred alternative,” according to the board’s motion. Plus, there are potential construction issues involving poor soil that would pose more challenges to the route, which rejoins and hugs I-5 where Highway 161 becomes Enchanted Parkway South.

What does it all mean?

Based on the board’s recent vote, the route north of the Enchanted Parkway station remains Sound Transit’s preferred route. That path diverges from I-5 around South 348th Street and connects to Highway 161. The line could pass perilously close to the Federal Way Inn and Suites — formerly the Red Lion — a hotel King County purchased in 2021 to be used as an emergency homelessness shelter.

The county has met with Sound Transit to talk through refining the route, county spokesperson Chase Gallagher said in February, and Sound Transit spokesperson David Jackson said in an email this week that “it’s too early in the process to identify specific property impacts.”

What has changed is part of the line south of 352nd Street. The agency no longer has a preferred choice for how it proceeds south from there and instead has at least a few options to consider, including:

• Maintaining the preferred alternative line, which re-joins I-5 at its intersection with SR 161. This could jeopardize Tribal resources and be hampered by poor soil, according to Sound Transit.

• Building the line west along Highway 99, connecting with Pacific highway before ultimately rejoining the freeway near Milton.

ST 3 Timeline

The Tacoma Dome extension will connect service from the upcoming downtown Federal Way station to the Tacoma Dome across nearly 10 miles of track. The $3.3 billion light rail extension was first planned to open in 2030, and later delayed to 2032. Sound Transit spokesperson David Jackson said the new delay to 2035 “reflects the time required to study” those new options that went before the board.

(The Mirror previously erroneously reported the start of construction on the Tacoma Dome station. It’s currently projected to begin in 2028, according to a spokesperson.)

The timeline for the Sound Transit light rail system expansion through Federal Way and Tacoma changes frequently, but currently looks like this:

• 2016: Voters approve the $58.3 billion ST3 ballot measure, expanding light rail service south through Tacoma, north through Everett, east through Issaquah and west through Ballard and West Seattle.

• 2024: Last estimated time of opening for downtown Federal Way light rail station. Construction completion will take more time and go “some number of months into 2025,” and the current opening is to be determined.

• 2026: Design process starts for Tacoma Dome extension project. Board likely makes final decision on light rail route through Federal Way and Pierce County.

• 2028: Construction starts on Tacoma Dome extension project

• 2035: Start of service to Tacoma Dome light rail station