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To learn about Sound Transit's current and planned projects explore the new System Expansion interactive map. This website is no longer being updated.

What are Candidate Priority Projects?

As part of the planning process to determine how and where our regional mass transit system should expand, Sound Transit identified a draft priority projects list shown on the map below. After incorporating public feedback, projects on the final list will be studied for possible inclusion in an ST3 ballot measure that could go to voters as early as November 2016. Starting in fall 2015, further analysis will help narrow the options that could be included in a ballot measure.


  • Light RailLight Rail
  • Commuter RailCommuter Rail
  • BusBus

North Corridor

Central Corridor

South Corridor

East Corridor