1 Line (Sound Transit)
The 1Line, formerly Central Link, is a light rail line in Seattle, Washington, United States, and part of Sound Transit's Link light rail system. It serves 26 stations in King and Snohomish counties, traveling between and stations. The line connects Lynnwood, Mountlake Terrace, Shoreline, the University District, Downtown Seattle, the Rainier Valley, Seattle–Tacoma International Airport, Kent, Des Moines, and Federal Way. The 1Line carried over 28.9million total passengers in 2024, with an average of nearly 80,000 daily passengers on weekdays. It runs for 20 hours per day on weekdays and Saturdays, with headways as low as six minutes during peak hours, and reduced 18-hour service on Sundays and holidays.
Trains are composed of three or more cars that each can carry 194 passengers, including 74 in seats, along with wheelchairs and bicycles. Fares are paid through the regional ORCA card, paper tickets, or a mobile app. Sound Transit uses proof-of-payment to verify passenger fares, employing fare ambassadors and transit police to conduct random inspections. Until August 2024, fares were calculated based on distance traveled. All stations have ticket vending machines, public art, bicycle parking, and bus connections, while several also have park-and-ride lots.
Voters approved Central Link in a 1996 ballot measure and construction began in 2003, after the project was reorganized under a new budget and truncated route in response to higher than expected costs. The light rail line, which followed decades of failed transit plans for the Seattle region, opened on July 18, 2009, terminating at in the Downtown Seattle Transit Tunnel and near Sea–Tac Airport. It was extended south to in December 2009, north to the University of Washington in March 2016, and south to Angle Lake in September 2016. The line was temporarily renamed the Red Line until its designation was changed to the 1Line in 2021, coinciding with an extension to Northgate.
The first cross-county extension, north to Lynnwood, opened in August 2024. A further southern extension to Federal Way opened in December 2025. The 2Line, planned to connect Seattle to the Eastside suburbs, will form a multi-line network via its connection with the 1Line in early 2026. Further expansion under Sound Transit 3 will divide the current corridor between two lines, the 1Line from Ballard to Tacoma and the 3Line from Everett to West Seattle.
History
Background and early transit proposals
Public transit service within Seattle began in 1884, with the introduction of the city's first horse-drawn streetcar line. The system had been replaced with a network of electric streetcars and cable cars by the end of the decade, which spurred the development of new streetcar suburbs across modern-day Seattle. Interurban railways to Everett, Tacoma, and the Rainier Valley were established after the turn of the century, giving the region an intercity passenger rail system to feed the streetcar lines. The interurban system failed to compete with the increasing popularity of automobile travel, capped by the completion of U.S. Route 99 in the late 1920s, and was shut down. By 1941, the streetcars had also been acquired by the municipal government and replaced with a trolleybus network.Various proposals for a rapid transit system in Seattle, to replace the streetcar—and later bus—networks, were presented in the 20th century and rejected by city officials or voters due to their cost or other factors. In 1911, urban planner Virgil Bogue proposed a system of subway tunnels and elevated railways as the centerpiece to a comprehensive plan for the city, which was rejected by voters. The Seattle Center Monorail, originally built for the 1962 World's Fair, has been the subject of several unsuccessful expansion proposals backed by Governor Albert Rosellini in the 1960s and Seattle voters in the early 2000s. The Forward Thrust Committee of the late 1960s proposed a rapid transit system, to connect Downtown Seattle to Ballard, the University District, Lake City, Capitol Hill, Bellevue, and Renton. The federal government offered to fund two-thirds of the rail system's capital costs, approximately $770million, if $385million in local property taxes were approved by voters. The rapid transit initiative was placed on the ballot in February 1968, but fell short of the supermajority needed to pass. A second attempt in May 1970, with $440million in local funding and $870million in federal funding, failed amid a local economic downturn caused by layoffs at Boeing. The federal funding earmarked towards the rapid transit system was granted to Atlanta, Georgia, forming the initial funding for the Metropolitan Atlanta Rapid Transit Authority's rail system.
Light rail planning
Following the failed Forward Thrust initiatives, Metro Transit was created in 1972 to oversee a countywide bus network, and plan for a future rail system. In the early 1980s, Metro Transit and the Puget Sound Council of Governments explored light rail and busway concepts to serve the region, ultimately choosing to build a downtown transit tunnel that would be convertible from buses to light rail at a later date. The PSCOG formally endorsed a light rail plan in 1986, recommending a system be built by 2020, and include a line between Seattle and Sea-Tac Airport, with routing alternatives that served the Rainier Valley. A 1988 advisory measure on light rail planning was passed in King County, encouraging Metro Transit to accelerate the plan's timeline to open by 2000. In 1990, the state legislature endorsed the creation of a regional transit board composed of politicians from King, Pierce, and Snohomish counties, with the goal of implementing the regional transit plan. Several members of the Seattle City Council endorsed the rail plan on the condition that it pass through the Rainier Valley, by then an economically disadvantaged and majority-minority neighborhood.The Central Puget Sound Regional Transit Authority, later renamed Sound Transit, was created in 1993 to write and present a regional transit plan for voter approval. The agency proposed a light rail network as the centerpiece of a $6.7billion transit ballot measure, with a surface line through the Rainier Valley and tunnels between Downtown Seattle, Capitol Hill, and the University District. The ballot measure failed to pass on March 14, 1995, and the light rail line was shortened to, between the University District and Sea-Tac Airport. Voters approved the $3.9billion package on November 5, 1996, along with increases to sales taxes and motor vehicle excise taxes across the regional transit district. Sound Transit considered several routing options during a series of public hearings and studies early into the project's environmental impact study, which adopted the name "Central Link". In 1999, Sound Transit selected the alignment for the light rail project, consisting of a line between the University District and Sea-Tac Airport, with surface segments passing through Tukwila, the Rainier Valley, and SoDo, and tunnels under Beacon Hill, First Hill, Capitol Hill, and Portage Bay.
Budget issues and delays
The Central Link project was originally planned to open in 2006 and projected to cost $1.9billion, but the estimates were found to be unrealistic by auditors in November 2000. New executives, hired by Sound Transit to replace previous program directors, presented a revised plan with an opening date pushed back three years to 2009 and a $3.8billion cost estimate. Planning of the Portage Bay tunnel between Capitol Hill and the University District was suspended due to higher than expected contractor bids, attributed to difficult soil conditions. Sound Transit adopted the revised budget and schedule in January 2001, including provisions to re-study routing options between Downtown Seattle and the University District, along with a $500million federal grant agreement to fund the construction of an "initial segment" for the project. The initial segment identified and approved by Sound Transit later that year shortened the line to, between Downtown Seattle and a southern Tukwila station near Sea-Tac Airport. The remaining routes to the airport and University District were sent back to the planning stage, and re-organized into separate light rail projects.In November 2001, Sound Transit approved construction of the shortened Central Link light rail project, calling for a summer 2002 groundbreaking. Property acquisition in the Rainier Valley began in March 2002, but two legal battles delayed the start of construction. In November 2002, the King County Superior Court ruled in favor of Sound Transit in a lawsuit filed by light rail opponents, alleging that it lacked the authority to shorten a voter-approved line. The approval of Tim Eyman's Initiative 776 threatened to repeal motor vehicle excise taxes needed to fund Sound Transit's budget, but was declared unconstitutional in February 2003. Another routing change requested by the City of Tukwila, placing light rail tracks along freeways in lieu of International Boulevard, was approved by Sound Transit and the Federal Transit Administration in 2002, moving the project closer to construction.
Construction and testing
Sound Transit received its $500million federal grant agreement in October 2003, and a groundbreaking ceremony was held in SoDo on November 8, 2003. Construction contracts for various segments were awarded in 2004 and 2005, coming six percent under Sound Transit's estimates, and work began along all parts of the system. Construction of the bridge over the Duwamish River in Tukwila was delayed by the discovery of more than 900 indigenous Coast Salish artifacts in February 2005; work was halted for a six-week excavation and examination by archeologists, including from the Muckleshoot Tribe. The first rails were installed on August 18, 2005, in the SoDo area; a month later, the downtown transit tunnel closed for a two-year renovation to accommodate light rail service. Excavation of the Beacon Hill tunnel and station began in 2005, and two tunnel boring machines were launched in early 2006 to bore the twin tunnels between SoDo and the Rainier Valley.The SODO and Stadium stations were completed in May 2006, and light rail testing in the SoDo area began the following March. Testing was extended to the re-opened downtown transit tunnel in September 2007, initially limited to weekends without bus service, and further to the Rainier Valley after the completion of the Beacon Hill tunnel in 2008. The elevated guideway in Tukwila, including crossings over major freeways and the Duwamish River, was completed in 2007 after the installation of 2,457 precast concrete segments and balanced cantilever bridges. During construction in the Rainier Valley, Sound Transit and the City of Seattle offered $50million in mitigation funds and development opportunities to affected businesses. Construction of light rail along Martin Luther King Jr. Way South also resulted in utility lines being moved underground, improved sidewalks, street crossings, and landscaping.