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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 This website is no longer being updated.

Major infrastructure projects require significant time to plan, design and build. Sound Transit heard loud and clear strong interest from around the region for shortening project timelines where feasible, and is exploring options for schedule savings. Variables can include lengthy environmental review and coordination with local jurisdictions. The Puget Sound region’s high level of existing development and its challenging geography and geology further adds to project complexity and timelines.

Due to these factors, planning and building major light rail projects typically takes 12-17 years, and longer for projects that are particularly complex due to design, construction and permitting challenges, such as the extensive underground construction through downtown Seattle for extending light rail to Ballard. Learn more on the project delivery factsheet.