3 Line (Sound Transit)

3 Line
Public presentation at Mariner High School, Everett
Overview
StatusPlanned
OwnerSound Transit
LocaleSeattle metropolitan area, Washington, US
Termini
Stations24 (8 new, 1 provisional)
Service
TypeLight rail
SystemLink light rail
History
Planned opening2035 (West Seattle)
2037 (Southwest Everett)
2041 (Downtown Everett)
Technical
Number of tracks2
CharacterUnderground, elevated, and surface
Track gauge4 ft 8+1⁄2 in (1,435 mm) standard gauge
ElectrificationOverhead line, 1,500 V DC
Operating speed55 mph (89 km/h)
Route map

Legend
Provisional route
 Everett Station (2041)
Amtrak Cascades Sounder commuter rail
SR 526/Evergreen (2041)
 SW Everett Industrial Center (2037)
 SR 99/Airport Road (provisional) (TBD)
 Mariner (2037)
 Ash Way (2037)
 West Alderwood (2037)
Up arrow Everett Link Extension
 Lynnwood City Center
Mountlake Terrace
 Shoreline North/185th
Shoreline South/148th
 Pinehurst
 Northgate
 Roosevelt
 U District
 University of Washington
Montlake Cut
 Capitol Hill
First Hill Streetcar
to Ballard (2042/2060)
 Westlake
Seattle Center Monorail South Lake Union Streetcar
 Symphony
Pioneer Square
Colman Dock
International District/
Chinatown
Amtrak Cascades Sounder commuter rail First Hill Streetcar
to Downtown Redmond
 Stadium
Greyhound Lines
reroute (2042/2060)
 SODO
to Federal Way Downtown
Down arrow West Seattle Link Extension (2032)
Duwamish Waterway
 Delridge
 Alaska Junction
This diagram:

The 3 Line (colored magenta) is a future Link light rail line in the Seattle metropolitan area in the U.S. state of Washington, to be managed by Sound Transit. Under preliminary plans, the line would connect Everett and Snohomish County to Downtown Seattle and West Seattle. It would share tracks with the 2 Line from southern Everett to International District/Chinatown station and replace the 1 Line. The line is planned to reuse existing tracks that are part of the 1 Line, which will rerouted through a new Downtown Seattle tunnel to be built for the Ballard Link Extension. The 3 Line comprises two projects that were approved in the regional Sound Transit 3 ballot measure, which was approved by voters in 2016.

The northern project is the Everett Link Extension, which has seven planned stations and covers 16.3 miles (26.2 km) between Lynnwood and Everett Station. As of 2026, the project is in the environmental review process and has an estimated cost of $11.6 billion. It has funding for six stations in Lynnwood and Everett; a seventh station at State Route 99 and Airport Road is provisional and would require additional funding. The southern four stations between Lynnwood and the Boeing Everett Factory area are scheduled to open in 2037, followed by the extension to Everett Station in 2041. The route of the Everett Link Extension is primarily elevated and follows Interstate 5 except for a deviation to the west to serve Paine Field, which was selected in 2022 after it was endorsed by local political leaders. The project also includes an operations and maintenance facility that is scheduled to open in 2034 at one of three sites near Paine Field and the Boeing Everett Factory.

The West Seattle Link Extension at the southern end of the 3 Line comprises two stations and 3.9 miles (6.3 km) of track that travel southwest from SODO station on the 1 Line corridor. It is scheduled to open in 2035 and is estimated to cost $7 billion to construct. The extension includes a high bridge crossing the Duwamish River adjacent to the existing West Seattle Bridge and a tunnel to approach the terminus station at Alaska Junction, a major commercial district. The Duwamish River would be crossed by a cable-stayed bridge that is 1,690 feet (520 m) long and supported by two towers that are 374 feet (114 m) tall. The Federal Transit Administration issued their preliminary approval for the West Seattle project via a record of decision in April 2025.

The West Seattle project was originally anticipated to open in 2030 but was delayed after cost projections had risen. An additional station near Avalon Way and 35th Avenue West was removed in a May 2026 decision by the Sound Transit board of directors to save costs. The first major construction contractor for the West Seattle section was selected in October 2026 to build the Duwamish River bridge and elevated guideway near SODO station; construction is scheduled to begin in late 2027. The West Seattle section is anticipated to carry 26,000 daily passengers and take 15 minutes to reach Downtown Seattle.

Stations

Names and locations for future stations are provisional.

Station City Location Planned
opening		 Type Notes
Everett Link Extension (Everett Station to Lynnwood City Center)
Everett Station Everett Broadway at Pacific Avenue 2041 Elevated Parking for up to 1,000 vehicles
SR 526/Evergreen Everett State Route 526 at Evergreen Way 2041 Elevated
SW Everett Industrial Center Everett State Route 526 at Airport Road 2037 Elevated
SR 99/Airport Road Everett Airport Road at State Route 99 TBD Elevated Provisional station
Mariner Everett 4th Avenue West at 128th Street Southeast 2037 Elevated 2 Line terminus; parking for 550 vehicles
Ash Way Lynnwood Interstate 5 at 164th Street Southwest 2037 Elevated
West Alderwood Lynnwood Vicinity of Alderwood Mall 2037 Elevated
West Seattle Link Extension (SODO to Alaska Junction)
Delridge Seattle Delridge Way Southwest near Southwest Genesee Street 2035 Elevated
Alaska Junction Seattle Southwest Alaska Street near California Avenue Southwest 2035 Underground

References

  1. 1 2 "Everett Link Extension: Timeline and milestones". Sound Transit. Retrieved September 4, 2024.
  2. 1 2 3 4 5 Sound Transit future service (PDF) (Map). Sound Transit. September 2026. Archived (PDF) from the original on October 1, 2026. Retrieved October 25, 2026.
  3. ↑ "2022 Progress Report". Sound Transit. February 2022. Retrieved January 2, 2023.
  4. ↑ Lindblom, Mike (October 24, 2019). "Pricier light-rail tunnels into Ballard and West Seattle fall by the wayside". The Seattle Times. Retrieved January 2, 2023.
  5. ↑ Watanabe, Ben (December 8, 2021). "City of Everett outlines light rail priorities for 2037". The Everett Herald. Retrieved January 2, 2023.
  6. 1 2 Geschke, Will (October 14, 2026). "Sound Transit shares info on Everett Link light rail at open house". The Everett Herald. Retrieved October 25, 2026.
  7. ↑ Geschke, Will (September 17, 2026). "Sound Transit to release major Everett Link planning document". The Everett Herald. Retrieved October 25, 2026.
  8. ↑ Watanabe, Ben (September 29, 2022). "Snohomish County leaders reject light rail routes bypassing Paine Field". The Everett Herald. Retrieved October 25, 2026.
  9. 1 2 3 4 5 "Executive Summary" (PDF). Everett Link Extension Draft Environmental Impact Statement. Sound Transit. September 2026. pp. iv, 4–6. Retrieved October 25, 2026.
  10. ↑ "Everett Link Extension fact sheet" (PDF). Sound Transit. September 2023. Retrieved September 4, 2024.
  11. ↑ Lindblom, Mike (June 23, 2023). "Sound Transit charts its long light-rail journey to Everett". The Seattle Times. Retrieved September 4, 2024.
  12. 1 2 3 Lindblom, Mike (August 13, 2026). "Light rail arrival in West Seattle delayed again". The Seattle Times. Retrieved August 14, 2026.
  13. ↑ "West Seattle and Ballard Link Extensions: Expanding light rail in Seattle" (PDF). Sound Transit. August 2022. Archived from the original (PDF) on September 17, 2017. Retrieved January 2, 2023.
  14. ↑ Newcomb, Tim (October 30, 2024). "Sound Transit Finalizes West Seattle Link Extension Alignment". Engineering News-Record. Retrieved December 2, 2024.
  15. ↑ Miller, Brian (August 19, 2024). "Behold! Sound Transit shows 'diamond pylon' span over Duwamish". Seattle Daily Journal of Commerce. Retrieved September 4, 2024.
  16. ↑ "Another step forward for West Seattle Link". Seattle Daily Journal of Commerce. May 1, 2025. Retrieved May 3, 2025.
  17. ↑ "Sound Transit Board adopts updated ST3 system plan" (Press release). Sound Transit. May 28, 2026. Retrieved June 21, 2026.
  18. ↑ "Team picked for West Seattle Link". Seattle Daily Journal of Commerce. October 14, 2026. Retrieved October 25, 2026.
  19. ↑ Lindblom, Mike (November 12, 2023). "West Seattle's light-rail path finally takes shape, at a price". The Seattle Times. Retrieved September 4, 2024.
  20. ↑ Lindblom, Mike (September 18, 2024). "West Seattle's light rail estimate soars past $6 billion". The Seattle Times. Retrieved December 2, 2024.
  21. ↑ "West Seattle Link Extension fact sheet" (PDF). Sound Transit. September 2026. Retrieved October 25, 2026.