Link light rail is a light rail system with some rapid transit characteristics that serves the Seattle metropolitan area in the U.S. state of Washington. It is managed by Sound Transit in partnership with local transit providers, and comprises three lines that total with 51 stations. The 1Line and 2Line travel on shared tracks from Lynnwood in Snohomish County to Seattle and split to serve other portions of King County. The 1Line continues south to the Rainier Valley, Seattle–Tacoma International Airport, and Federal Way; the 2Line crosses Lake Washington to the Eastside cities of Bellevue and Redmond. The TLine is disconnected from the other lines and operates as a streetcar for in Tacoma. In 2025, the system had a ridership of 39.1million, or about per weekday as of , primarily on the 1Line. Trains run at frequencies of 4 to 20 minutes.
The Link light rail system was originally conceived in the 1980s following several earlier proposals for a heavy rail subway system that were rejected by voters. Sound Transit was created in 1993 and placed a ballot measure to fund and build the system, which was passed on its second attempt in 1996. Tacoma Link began construction in 2000 and opened on August22, 2003, becoming the first modern light rail system in the state. Central Link construction in Seattle was delayed because of funding issues and routing disputes, but began in November 2003 and was completed on July18, 2009. The trains initially ran from Downtown Seattle to Tukwila International Boulevard station before being extended south to Seattle–Tacoma International Airport in December2009. Further extensions north to the University of Washington and south to Angle Lake station opened in 2016 to complete most of the line's original planned route. An extension from the University of Washington to Northgate station opened on October2, 2021, followed by a northern extension to Lynnwood City Center station on August30, 2024, and a southern extension to Federal Way Downtown station on December6, 2025.
The first phase of the 2Line opened on April27, 2024, between South Bellevue and Redmond Technology stations; an extension east to Downtown Redmond opened in May2025. It was extended west to Seattle on March28, 2026, following construction delays on a section crossing Lake Washington. The 2Line and Lynnwood sections were funded by Sound Transit 2 (ST2), a 2008 ballot measure to expand the transit system, along with planning work for other projects. The Sound Transit 3 (ST3) ballot measure was approved in 2016 and funds plans to expand the Link network to and 83 stations by the 2050s. The expansions are planned to cover the metropolitan area from Everett to Tacoma, along with branches to Kirkland, Issaquah, and the Seattle neighborhoods of Ballard and West Seattle.
History
Predecessors and earlier proposals
The first form of scheduled public transportation in the Puget Sound region was various steamboat ferries that later evolved into the "mosquito fleet" in the 1880s as the area's population grew. They were followed by streetcar systems, beginning with Seattle's first horse-drawn line in 1884 and Tacoma's in 1888, built by private companies alongside conventional railroads. Electric streetcars and cable cars debuted in 1889 under other companies and continued to grow outward into new residential developments called streetcar suburbs. The lines were consolidated into the Seattle Municipal Street Railway in 1919, which grew to 26 routes with of track. Interurban railways that connected Seattle to Everett and Tacoma were built by Stone & Webster, but ceased operations by 1939 due to competition from automobiles on new highways as well as financial issues.
Attempts to finance the construction of a rapid transit system to connect Seattle's neighborhoods, and later other cities in the region, first emerged with civil engineer Virgil Bogue's comprehensive plan in 1911. A referendum on the plan, which included of subway tunnels and of elevated tracks, was rejected by city voters the following year. The region's transit system faced chronic underinvestment and declining bus ridership as new highways and freeways, including Interstate 5 through Seattle, were constructed to serve a growing number of automobile users. A proposal for a Seattle subway system with suburban extensions to Bellevue and Renton was part of the Forward Thrust series of civic ballot measures in the 1960s. It would use federal funding to cover two-thirds of the $1.15billion (equivalent to $ in dollars) construction cost, contingent on the approval of local funding, and be completed by 1985. The transit ballot measure, in February 1968, was approved by 51percent of voters but failed to reach the 60percent threshold required by the state government to issue municipal bonds. A second vote in May 1970 received only 46percent approval due to the "Boeing bust", a local economic downturn caused by layoffs at Boeing, a major employer. The federal funding that was earmarked for the Seattle project was instead reallocated to the Metropolitan Atlanta Rapid Transit Authority in Atlanta, Georgia.
The Seattle Transit System, which operated buses within the city, launched one of the nation's first express bus systems in 1970. The program drew new suburban riders but the system continued to face financial issues. King County voters approved a ballot measure in 1972 to acquire the Seattle Transit System and a private suburban operator to form a new countywide bus system that would be managed by the Municipality of Metropolitan Seattle, an existing water treatment and sewage agency. The bus system, named Metro Transit (now King County Metro), began operations in January 1973 and increased ridership from 30million with Seattle Transit in 1971 to 66million in 1980. Metro Transit's buses had difficulty navigating through Downtown Seattle, where 420trips during peak periods led to congestion in bus lanes and at stops. The Downtown Seattle Transit Tunnel, with five stations on 3rd Avenue and Pine Street, was opened in September 1990; it would redirect bus trips from downtown streets but was also designed to be converted to future light rail use.
Rail plans and Tacoma launch
In 1975, Metro began a long-term study into regional transit that was later merged with an effort from the Puget Sound Council of Governments (PSCOG), the region's designated metropolitan planning organization. A grant for the study from the Urban Mass Transit Administration was instead allocated to TriMet in Portland, Oregon, due to the federal government's reluctance to lose an "example all-bus system" like Metro Transit's. The regional transit study proceeded and their initial findings in 1981 recommended a light rail system that would be able to operate on streets in some areas but generally follow freeway corridors to regional centers. A related study from the Snohomish County Transportation Authority began in 1983 and determined an extension of a future light rail line along Interstate 5 would be feasible. The Metro–PSCOG study, published and adopted in 1986, recommended a light rail system with three lines from Downtown Seattle that followed freeway corridors: along Interstate 5 north to Lynnwood and south to Federal Way; and east across Lake Washington to Bellevue. The recommended system had a projected completion by 2020 if approved by voters and a cost of approximately $14billion (equivalent to $ in dollars) to construct.
A non-binding advisory ballot measure on accelerated development of a light rail system was approved by King County voters in November 1988. The state legislature authorized the creation of a regional transit board that would have representatives from King, Pierce, and Snohomish counties. Another study resulted in a long-range plan for a three-county transit system with of light rail from Everett to Tacoma and Redmond, along with commuter rail and express buses. The Central Puget Sound Regional Transit Authority (RTA) was formed in September 1993 after approval from the state legislature and the three county councils; the RTA would create a construction and financing plan for approval by voters in a regional ballot measure. Their first attempt, which included a light rail network with lines as far north as Lynnwood and as far south as Tacoma, had an estimated cost of $6.7billion (equivalent to $ in dollars). It was rejected by 53percent of voters on March 14, 1995.
A revised RTA plan announced the following year scaled back the light rail component to a corridor between Seattle–Tacoma International Airport and University District in Seattle and a separate line that would connect Downtown Tacoma to a multimodal hub near the Tacoma Dome. The new package, named Sound Move, was estimated to cost $3.9billion (equivalent to $ in dollars) and would be funded by a sales tax and motor vehicle excise tax. It was approved by 56.5percent of voters in the urbanized Seattle metropolitan area, including majorities in all three counties, on November 5, 1996. The RTA renamed itself to Sound Transit in August 1997 and adopted "Link" as the name for the light rail system along with Sounder for commuter rail and Regional Express for buses.
The Downtown Tacoma line, named Tacoma Link, was preceded by a shuttle bus from the new Tacoma Dome Station built by Pierce Transit in 1997. The project was anticipated to revitalize the city's downtown and serve the new University of Washington Tacoma campus along its route. Tacoma Link began construction in October 2000 and its rolling stock—three streetcars imported from the Czech Republic—arrived in September 2002. The line opened on August 22, 2003, with five stations, and cost $80.4million (equivalent to $ in dollars) to construct. It had no fares and exceeded its 2010 ridership projections by early 2003, carrying its 500,000th passenger in April of the year.
Central Link planning and construction
Planning and construction of Central Link, the light rail line that would travel through Downtown Seattle, was delayed several times due to increased costs and political scrutiny over its alignment. The preferred route, selected in November 1999, ran from Northgate Transit Center in Seattle to Seattle–Tacoma International Airport. It integrated with the downtown transit tunnel, required the construction of a new tunnel under Portage Bay and through Beacon Hill, and followed surface streets in the Rainier Valley area and Tukwila. It would cost $1.85billion (equivalent to $ in dollars) to construct the section from the University of Washington campus to the airport, which had been funded in the Sound Move plan. The cost had increased significantly from the original plan's budget due to unexpected property acquisitions that would be needed. The use of at-grade tracks in the Rainier Valley was opposed by a citizens' group, which filed a lawsuit against Sound Transit to add a tunnel to plans.