On Tuesday, Sound Transit and local elected officials broke ground on the first inter-county light rail project to be built in Washington state: Lynnwood Link. Although visible construction on Lynnwood Link has been underway for months, the final contracts and funding agreements were only recently approved by Sound Transit and the Federal Transit Administration (FTA).
Lynnwood Link will extend light rail service on the Red and Blue lines by 8.5 miles along Interstate 5, passing through Shoreline and Mountlake Terrace before terminating at Lynnwood Transit Center, the main bus hub in South Snohomish County. Community Transit is planning a massive truncation of its commuter routes to feed into light rail trains, taking advantage of the more reliable travel times to reinvest service hours into expanded local routes. Several bus rapid transit routes, including the Stride network and the Swift Blue and Orange lines, will intersect with Link at stations built along the Lynnwood corridor.
The project was approved as part of ST2 in 2008 and is the final light rail project from the program, discounting projects that were absorbed into ST3 like the extensions to Federal Way and Downtown Redmond. It was originally anticipated to begin service in 2023, but was pushed back by six months into 2024 because of design changes and cost overruns brought on by the local construction boom. The current project budget is $2.9 billion, of which 40 percent will be paid through a $1.17 billion full funding grant agreement with the FTA that was signed late last year.
Within a few years of its opening, Sound Transit anticipates that Lynnwood Link will be carrying around 50,000 daily passengers, including the bulk of commuters from throughout Snohomish County. The individual stations are already being prepared for transit-oriented development, including Lynnwood’s vision of a dense city center at its station and Mountlake Terrace building a new town center within blocks of the transit center. Lynnwood is also going a step further by encouraging density around Alderwood Mall, which is slated to receive light rail service in 2036 as part of the Everett extension approved in ST3.
The projected travel time of 28 minutes between Lynnwood and Westlake is equal to current bus travel times in light to moderate traffic, but provides a great improvement over peak travel times. Train frequencies of 4–6 minutes during peak periods will also match those of current peak expresses (which combine to form a trunk along I-5), and the 10-minute off-peak frequency will be double that of the off-peak Route 512.
All four stations on Lynnwood Link will feature bus bays for connecting routes, parking garages (totaling 2,900 new stalls), and pathways towards major trails — including the Interurban Trail and a new “trail along the rail” in Shoreline. The three elevated stations will look similar to that of Northgate or South Bellevue, with a center platform and two entrances that anchor each end; Shoreline North/185th Station will be built with a below-grade center platform with two entrances and a large bus layover area for the Swift Blue Line.
A fifth station at Northeast 130th Street in north Seattle was approved in ST3 and is currently set to open in 2031, but has recently entered accelerated engineering. Sound Transit plans to determine whether a simultaneous opening with the rest of the extension is feasible in a non-disruptive manner, and the matter will be taken up by the agency’s board of directors sometime later this year. For now, the preliminary plan for Northeast 130th Station is an elevated center platform on the north side of its interchange with Interstate 5, which could serve as an alternative bus transfer for routes that will stop at Shoreline South/145th Station.
The construction of Lynnwood Link will be split into two projects on the north and south sides of the Snohomish–King county line at State Route 104. The $752 million southern contract from Northgate to Northeast 200th Street will be handled by a joint venture of Stacy and Witbeck, Kiewit, and Hoffman Construction, all familiar names who worked on previous Link projects. The contract covers two stations, 1.5 miles of elevated guideway, and 3 miles of grade-separated surface rail or retained cut sections. The $778 northern contract from Northeast 200th Street to Lynnwood was awarded to Skanska USA, whose largest transportation projects include New York City’s Second Avenue Subway and the roadway within the State Route 99 Tunnel.
For the remainder of the year, construction crews will continue clearing the eventual path for the light rail guideway, which involves the cutting of 5,300 trees (and eventual four-fold replacement). Utility lines and sound walls are also being relocated to prepare for guideway column drilling, which is set to begin later this year. During construction, there will be periodic closures of parking stalls at the park-and-rides, which will be replaced by satellite lots and small route modifications for buses. In total, over 4.4 million labor hours will be needed to complete the project, which is anticipated to wrap up major construction in mid-2023 ahead of a year-long systems testing process.