Sound Transit 3

Sound Transit 3
Name	Sound Transit 3
Type	Transit expansion program
Location	Seattle metropolitan area, Washington
Outcome	Regional light rail, bus, and commuter rail expansions
Ballot	2016
Cost	$54 billion (approx.)
Agencies	Sound Transit

Sound Transit 3 is a multibillion-dollar regional transit expansion program approved by voters in 2016 to expand rapid transit, light rail, commuter rail, and bus services across the Seattle metropolitan area. Proposed by Sound Transit and placed on the ballot as a ballot measure, the program aimed to connect cities, neighborhoods, and institutions across King County, Pierce County, and Snohomish County. It accelerated projects that involved partnership with local jurisdictions, federal agencies, and private contractors.

Background and planning

The ballot measure followed decades of planning by regional agencies including Sound Transit, King County Metro, Community Transit, Pierce Transit, Puget Sound Regional Council, and coordination with municipal governments such as City of Seattle, City of Tacoma, and City of Bellevue. Earlier phases and initiatives included projects and plans associated with Sound Move, Sound Transit 2, and transit planning documents prepared alongside institutions like University of Washington and Seattle–Tacoma International Airport. Regional growth forecasts by the Puget Sound Regional Council and transportation studies involving the Federal Transit Administration, Washington State Department of Transportation, and research by University of Washington Department of Civil & Environmental Engineering influenced route selection and mode choices. Stakeholders ranged from elected officials including representatives from King County Council, Seattle City Council, and executives like the Governor of Washington to advocacy groups such as Transportation Choices Coalition and business groups including the Seattle Chamber of Commerce.

Projects and network expansions

The program outlined major expansions of light rail, commuter rail, and bus infrastructure with projects connecting downtown cores, suburban centers, and regional destinations. Key projects linked corridors serving Downtown Seattle, Northgate, University District, Capitol Hill, South Lake Union, Ballard, West Seattle, Federal Way, Tukwila, Redmond, Mercer Island, Bellevue, Issaquah, Lynnwood, Everett, Tacoma Dome, Puyallup, Kent, Auburn, and extensions toward Seattle–Tacoma International Airport. Planned nodes and stations referenced destinations like Museum of Pop Culture, CenturyLink Field, T-Mobile Park, Washington State Convention Center, Bellevue Transit Center, and connections to regional services such as Amtrak and Sounder commuter rail. The expansion included new light rail lines, tunnel projects under central business districts, elevated guideways, at-grade segments, parking facilities near centers like Northgate Mall and Angle Lake, and multimodal transfer hubs linked to Link light rail, Sounder, and bus rapid transit corridors like those serving Interstate 5 and State Route 99.

Funding and financing

Financing for the measure combined local revenue tools and capital markets mechanisms with projected federal grants. The package relied on voter-approved increases in sales taxes, property taxes, and motor vehicle excise taxes coordinated with county treasuries including King County Treasurer, Pierce County Treasurer, and Snohomish County Treasurer. The financing plan involved bond issuances under municipal law, debt service managed by Sound Transit Board of Directors, and anticipated funding from the U.S. Department of Transportation and programs administered by the Federal Transit Administration and Federal Highway Administration. Economic analyses cited agencies and institutions including Washington State Treasurer, Office of Financial Management (Washington), and private underwriters and rating agencies such as Moody's Investors Service and Standard & Poor's. Labor agreements and workforce provisions engaged trade unions like Transportation Trades Department, AFL-CIO and local labor councils.

Implementation and construction

Construction mobilized multiple contractors, designers, and engineering firms working under oversight by the Sound Transit program office and permitting authorities including Seattle Department of Construction and Inspections, Bellevue Development Services, and the Washington State Department of Ecology for environmental compliance. Major elements included tunneling operations using tunnel boring machines with environmental reviews prepared under the National Environmental Policy Act and state counterparts. Coordination with utilities and institutions involved entities like Seattle City Light, Puget Sound Energy, Port of Seattle, and the Port of Tacoma. Construction phases required traffic management plans with partners such as Washington State Department of Transportation for work near interstates and state routes and staging at rail facilities shared with BNSF Railway and Union Pacific Railroad. Project delivery methods involved design–bid–build, design–build, and public–private partnerships with oversight from municipal procurement offices and the Washington State Auditor.

Ridership and operational impacts

Projected ridership increases were based on models developed by firms and agencies including Sound Transit Planning Department, Puget Sound Regional Council travel demand models, and academic studies from University of Washington. Anticipated shifts in mode share affected services provided by King County Metro, Community Transit, and Pierce Transit, enabling network integrations at hubs like Westlake Station, University Street station, and International District/Chinatown. Operational impacts considered coordination with Amtrak Cascades, freight operations on corridors used by BNSF Railway, and scheduling interfaces with Sounder commuter rail service. Long-term forecasts addressed economic centers such as Downtown Bellevue and South Lake Union and institutions including Amazon (company) and Microsoft campuses influencing peak commuting patterns.

Controversies and public response

Public debate and controversy involved cost estimates, timelines, and local impacts with prominent voices including regional elected officials from King County Executive, Mayor of Seattle, and state legislators. Advocacy and opposition groups such as Transportation Choices Coalition, neighborhood associations, business coalitions like the Greater Seattle Chamber of Commerce, and fiscal watchdogs engaged in campaigns and public hearings. Legal challenges and environmental concerns prompted review by agencies including the Washington State Environmental Protection Agency and courts where municipal plaintiffs and interest groups filed suits. Media coverage by outlets including The Seattle Times, SeattlePI.com, and regional broadcast partners shaped public perception, while ballot campaigns mobilized resources through committees registered with the Washington Public Disclosure Commission.

Category:Transit in Washington (state)