The Sound Transit Board of Directors will meet today at 1.30pm to approve a final version of the Sound Transit 3 (ST3) plan. While last-minute amendments to the plan are possible, the Board of Directors is very likely to pass a package that closely resembles the one agreed upon earlier this month. The plan is wide ranging with an emphasis on light rail, commuter rail, and rapid bus transit expansions and improvements. Transit access improvements and future transit studies are also in the mix. Once approved by the Board, the proposal would be sent to the General Election ballot in November for voter approval.

Light Rail Expansion

The proposal would offer two light rail expansions in Seattle, one in Snohomish County, two on the Eastside, and another three on the south end.

The approved ST3 plan from the June 2nd board meeting. Click for larger version. (Sound Transit)
The approved ST3 plan from the June 2nd Board meeting. Click for larger version. (Sound Transit)

Seattle would get two new lines with 14 new or expanded stations and three infill stations. The West Seattle-Downtown line would be the first light rail deliverable in ST3 for Seattle, opening in 2030 with five new or expanded stations. Five years later, the Ballard-Downtown line would open in 2035 introducing a new Downtown tunnel and adding nine new or expanded stations (including a new midtown station). Both lines are planned to be fully grade separated. Seattle would also get infill stations in 2031 at 130th Street, Graham Street, and Boeing Access Road.

Snohomish County would get one new line and six new stations and a possible provisional station. Running from Lynnwood to Everett, the line would open by 2036 and deviate from a likely I-5 alignment via the Southwest Everett Industrial Center.

The Eastside is slated to get one new line, an extension, and seven new stations. The Redmond extension would open first in 2024 adding two new stations on the East Link line while the South Kirkland-Issaquah line would follow on 17 years later in 2041, adding five new stations (one of which is provisional) and connecting with East Link in Downtown Bellevue.

South King would technically get two extensions of the South Link line adding a total of three stations. The first extension would be from Kent/Des Moines to the Federal Way Transit Center, opening by 2024. The second extension would follow on in 2030 further south to the Tacoma Dome station. South King would see one new station at South Federal Way in that extension.

Pierce County would get two extensions and nine new stations. Sharing in the first extension of South Link in 2030, two stations would be added (one in Fife and another in East Tacoma). Later in the decade, an extension of Tacoma Link would be made from the Hilltop neighborhood to Tacoma Community College extension by 2039 with six new stations.

Sounder Improvements

Sound Transit’s Sounder service would get a mix of expansion and upgrades. The South Sounder line would be extended from Lakewood to DuPont by 2036, adding three stations along the way. Platforms on the corridor would be expanded to allow up to 10-car trains. Overall railway infrastructure would be beefed up with new tracks and signal upgrades. Station access for bikes, pedestrians, buses, and motorists would see vast improvements. And ST3 funding would help to buy more time slots on the BNSF rails, meaning more daily trips. These latter improvements are planned to be rolled out between 2024 and 2036.

The lone commitment on the North Sounder line is to provide additional parking at Edmonds and Mukilteo stations sometime around 2024.

Bus Service Improvements

Major investments would be made by focusing on bus rapid transit (BRT), enhancing speed and reliability of corridors, and improving access to key facilities. At the top of the list is BRT on I-405, SR-522, and Madison Street. Sound Transit plans to launch its first two BRT lines in 2024. The I-405 BRT line would run from Lynnwood Transit Center to Burien via Bellevue. This line would have 10 stops and intersect three light rail stations. Its companion BRT line on SR-522 would run from the Link station at NE 145th Street to UW Bothell–with some trips being extended to Woodinville–and have 10 stops. That line would primarily utilize business access and transit (BAT) lanes and transit priority techniques at chokepoints to speed buses along. An expanded UW Bothell transit center and three new parking facilities would be purpose built to feed riders onto the route.

Seattle would get a smattering of bus improvements. Sound Transit promises to make a combined contribution of $85 million for three BRT projects. The most substantial investment would be in the Madison Street BRT project, aiding the Seattle Department of Transportation to launch the line in coordination with Metro by 2024. Sound Transit is also providing capital contributions to make targeted improvements for speed and reliability on the successful RapidRide C and D lines.

In a similar way, Sound Transit has also agreed to make targeted capital improvements on Pacific Avenue in Tacoma and speeding up bus service on highways like I-90, SR-167, and SR-518 using shoulder lanes.


Sound Transit has agreed to six key corridor studies and four other studies like innovative technology and transit-oriented development. Four of the corridor studies would explicitly evaluate light rail and one would consider expansion of commuter rail. These include:

  • Extending light rail from West Seattle to Renton via Burien and Renton.
  • Extending light rail from Everett Station to North Everett.
  • Extending South Link from Tacoma Dome Station to the Tacoma Mall.
  • Constructing a new “Northern Lake Washington” light rail line that could cross anywhere from SR-522 on the north to SR-520 on the south. The line could ultimately connect Ballard to Kirkland, Bellevue, and Redmond through various alternatives.
  • Creating a spur on the South Sounder line to link Orting into the system by way of Sumner.

Another study would look at a variety of high capacity transit options between Bothell and Bellevue. The scope of the study wouldn’t be limited to just light rail; Sound Transit could consider other modal options like enhanced bus service and improvements, bus rapid transit, and commuter rail.

Look for livetweets of today’s Board meeting by The Urbanist team on Twitter (@UrbanistOrg) starting around 1.30pm. We’ll update this post if the Board makes any further significant refinements to the plan. So stay tuned.

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Stephen is a professional urban planner in Puget Sound with a passion for sustainable, livable, and diverse cities. He is especially interested in how policies, regulations, and programs can promote positive outcomes for communities. With stints in great cities like Bellingham and Cork, Stephen currently lives in Seattle. He primarily covers land use and transportation issues and has been with The Urbanist since 2014.