System expansion

Voters approved projects in 1996, 2008, and 2016. Sound Transit is building the most ambitious transit expansion in the country.

KEY

New service
Parking & access
Operations & maintenance facilities
Link light rail
Sounder rail
Stride bus rapid transit

Expansion projects

Long-term affordability

Delivering the ST3 vision

Sound Transit is working to close a $34.5 billion future funding gap projected through 2046 to deliver what's outlined in the voter-approved Sound Transit 3 program. ST3 includes light rail extensions to West Seattle, Ballard, Tacoma, and Everett, new service between South Kirkland and Issaquah, and much more.

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The Platform

The heart of Sound Transit’s mission is to provide the people of the Puget Sound region with an effective, affordable, and reliable public…
When the 2 Line Crosslake Connection opens on March 28, riders will not only experience a more connected region. Public art installations at the two…
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Latest project documents

Section 106, West Seattle Link Extension

Commitment tracking matrix, Spring 2026

(PDF Document | 150kB) Updated 03/26/2026

Section 106, West Seattle Link Extension

WSLE Section 106 quarterly report, March 2026

(PDF Document | 176kB) Updated 03/26/2026
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See all project documents