The long-awaited infill light rail station at S Boeing Access Road is set to move forward as a more defined project. A motion recommended by Sound Transit staff would shift the proposed station location a little over 1,000 feet southwest from the original representative project location, onto East Marginal Way S. If selected, the station location would proceed into detailed planning and environmental review, a process required for federal approval of the project.
Scheduled to open in 2031, the infill station would fill in a nearly six-mile gap between the 1 Line stations in Rainier Beach and Tukwila — though much of the area is industrial and low-density uses. The former station location was sandwiched between a Seattle Police Athletic Association shooting range, a dairy warehouse, and the Duwamish River. The new location is between the same sprawling shooting range, a tile warehouse, and an UPS freight terminal.
Developing a plan
Just over a year ago, Sound Transit kicked off a planning process to study alternatives for the S Boeing Access Road. The agency initially started with the original representative project location identified just south of S Boeing Access Road between I-5 and the BNSF tracks as a baseline for planning and eventually identified two other potential locations, with only one alternative location determined to pass a “fatal flaw” analysis.
Since its inclusion in the Sound Transit 3 (ST3) program, the main thrust behind the station has been to deliver a bus transfer and layover facility to allow for connections to I-5 running and local bus routes, a 300-stall surface parking lot, and improved light rail access to employers in nearby industrial areas and residential areas in North Tukwila and South Seattle.
But wider agency priorities have changed a lot since ST3 was approved by voters in 2016, such as a major reset of the capital program putting parking projects largely on hold and possibly facing eventual cancellation. Nevertheless, the infill station project has not yet dispensed with the parking concept, driving much of the project costs and design.
The alternatives considered
The representative project location would be sited primarily on vacant property. Its location near I-5 has the obvious benefit of nearly direct regional bus connections and a potential Sounder connection, if ever built. A variety of bus routes operate between Seattle and points south via I-5, such as Routes 101, 102, 150, 162, 177, 193, 577, 590, 594, and 595. The nearest local bus is Route 124, which travels along East Marginal Way S and Tukwila International Boulevard, a few blocks to the west.
Since the light rail alignment is already elevated, the station would need to be constructed with elevated platforms to the side of the existing guideway. In addition, the station would be supported by bus transfer and layover facilities and a parking lot.
The alternative project location would be sited primarily on private commercial property, requiring displacement of businesses. Shifting the station location means that longer-distance bus connections would be less convenient and lead to longer travel times and largely eliminates the usefulness of any potential Sounder infill station nearby. However, it would provide more direct access to Route 124, which provides local access to nearby industrial and residential areas.
The station would also be constructed with the same type of station features as the representative project. Sound Transit sees the station as having more upsides since it would avoid impacts to wetlands and offers flatter ground, and because the agency wouldn’t have to contend with the state transportation department and BNSF.
According to the motion recommending the station, the agency has a document that is supposed to outline the alternatives considered in more detail with an evaluation. The referenced report has a publishing date of this month, but it was conspicuously not readily available to review, despite the agency’s recommendation to the board. A Sound Transit public information officer told The Urbanist that the report should be released within the next week.
Despite Sound Transit’s recommendation, community feedback was fraught over what to do about a station in the area. Many commenters wanted a Sounder connection, transit-oriented land uses in the area, new pedestrian and biking infrastructure, and better access to Allentown. Others wondered what the utility of the station would really be.
Official estimates from 2016 predicted a meager 1,500 to 2,000 daily riders by 2040 for the infill station, and newer 2046 estimates mentioned by staff earlier this month suggested 1,600 to 2,100 daily riders. That’s still only about half of what the cheaper Graham Street infill station is predicted to net.
Costs for S Boeing Access Road infill station are projected to top $267 million, according to latest estimates. Translating that into a cost per rider added to the Link system, S Boeing Access Road is expected to cost $127,000 to $167,000 per rider added compared to Graham Street which is expected to cost $29,000 to $44,000 per rider added.
What wasn’t considered
Sound Transit did not elect to broaden its planning scope further by considering if the representative project location could be designed with a Sounder commuter rail connection reserved or studying alternative locations in and around Allentown.
In addition to better bus connections, the representative project location has the potential to offer an interchange with Sounder, if designed with such a connection in mind. Sound Transit originally planned that this station would do exactly that in the 1990s but project deferment in the early 2000s put any S Boeing Access Road Sounder station on the backburner.
When the station idea was brought back as part of ST3, a dual station option was put forward but only formal identification of the Link station was added into the ST3 package approved by voters. Nevertheless, the project has always been understood with an intent to facilitate a dual station. Seattle even formally identified a Sounder stop at this location in its adopted Seattle Transportation Plan last year.
A Sounder connection here may not seem the obvious choice, but the use case is varied. Sounder riders from the south would have more convenient transit access to jobs in nearby industrial areas, including Boeing. For local bus riders, Sounder trips into Downtown Seattle would offer an express connection, as well as to connecting Link service to Bellevue versus lengthier trips via Link in the Rainier Valley. Likewise, local bus riders and Link riders seeking to travel to jobs and destinations south of Seattle along the Sounder corridor would have faster transit trips. Some airport riders would also have faster trip times when using Sounder in tandem with Link. All of that is further bolstered if a Sounder stop is built in Georgetown, as Seattle hopes.
Yet, Sound Transit’s staff recommendation seems to suggest that lack of Sounder consideration in its alternatives analysis process hurt the representative project alternative. “In addition, a Sounder station proposed near the Boeing Access Road location (ST3 Representative Site) was removed from Sound Move by the ST Board in 2001; therefore, an ability to integrate a Boeing Access Road Sounder station was not included as a criterion in Alternatives Analysis.” The refusal to weigh that in the project alternatives process is head scratching.
Station alternatives a half-mile or so south in Allentown also never got airtime in the planning process. Compared to the more sprawling light industrial areas surrounding it, Allentown is a relatively urban area with a mix of housing, industry, and office parks, has better access to the Green River Trail, and could be well suited for future transit-oriented development. Several options near SR 599 could have been studied without accommodating parking, enabling the stations to focus on neighborhood walking and biking connectivity and convenient bus connections via I-5 and SR 599. That would almost certainly improve ridership since a station in the area would benefit from more all-day ridership generated within its walkshed.
Nevertheless, Sound Transit appears prepared to speed ahead with environmental review and conceptual engineering design for a station set to add few benefits to the regional transit system at high cost. If all goes according to plan, the station will open in 2031.
Stephen is a professional urban planner in Puget Sound with a passion for sustainable, livable, and diverse cities. He is especially interested in how policies, regulations, and programs can promote positive outcomes for communities. With stints in great cities like Bellingham and Cork, Stephen currently lives in Seattle. He primarily covers land use and transportation issues and has been with The Urbanist since 2014.
