For Seattle’s Next Light Rail Alignment, Sound Transit Weighs Short-Term Impacts Against Long-Term Gains

Plans show a deep Westlake Station, similar to the new U District Station pictured here.

By Lizz Giordano

The massive draft environmental impact statement  (DEIS) for the West Seattle-Ballard light rail extension landed on Sound Transit’s website in late January. It lays out the pros and cons of a variety of elevated and tunnel routes as the agency tries to weave light rail tracks through some of the densest parts of Seattle.

This second Seattle light rail line will start at the current SoDo station and cross the Duwamish Waterway before skirting the north edge of the West Seattle Golf Course on its way to the Alaska Junction. The Ballard spur will start in the Chinatown-International District (CID), then head north through a new tunnel under downtown toward Seattle Center, through Interbay, and over or under Salmon Bay to its terminus in Ballard.

This extension will add a second transit tunnel through downtown to handle increased train volumes (including the new extension to Everett, also part of Sound Transit 3) and new stations near existing ones at Westlake, the CID and SoDo, which will become transfer points between the two light rail lines.

Some options offer better bus connections or more potential for transit-oriented development. Other alternatives lessen construction impacts by moving stations to the fringes of the neighborhood or deep below ground.

While transit-oriented development is hardly the entire answer to Seattle’s housing crisis, building transit around stations is a must-do; in South Seattle, where Sound Transit failed to plan for housing two decades ago, the sparsely populated light rail line represents a series of missed opportunities.

As the Sound Transit board makes a final decision on the route, expected in 2023, board members will be weighing short-term construction impacts against building a system that’s easy and seamless for riders to use for decades. Those decisions might be a little easier now that the costs of elevated routes is similar to that of tunneling. But underground stations don’t always equal a better experience for riders.

To keep certain tunnel routes on the table for West Seattle and Ballard, as requested by many in those neighborhoods, Sound Transit board members representing King County proposed a last-minute compromise in 2019. It stipulated that while the agency staff would continue to study the more expensive tunnel routes, they would not move forward without third-party (non-Sound Transit) funding.

A few years later, the relentless increase in property values has made it just as expensive to build above ground as to tunnel beneath the city for third-party funding.

In Ballard, where there are basically four options—an elevated or underground station at NW Market Street and either 14th or 15th Ave. NW—the price tag for the elevated options is now almost identical to the estimated cost to tunnel: Between $1.5 billion and $1.6 billion, compared to $1.5 billion to $1.7 billion for the tunnel alternatives.

As the cost difference has evaporated, Seattle Subway, a transit advocacy group, hopes to persuade the agency to revive an old proposed route along 20th Avenue Northwest that would deliver riders closer to the core of the neighborhood rather than several blocks east. Serving dense neighborhoods (rather than more car-centric areas on their periphery) is a core urbanist tenet: High-capacity transit works best when it serves a dense core of riders, and easy access to transit can spur more density in urban areas.

To fully resurrect this option, however, Sound Transit would have to create an entirely new environmental impact statement, which is no easy task and could add time to the project.

If that doesn’t happen, routes along 14th Avenue NW might offer the best combination of transit connections and development potential. The 14th Avenue location provides better transfers between buses and trains than alternatives on 15th Avenue, while also avoiding the need to build a moveable bridge over Salmon Bay.

A buried route along 14th would also create opportunities for transit-oriented development on Sound Transit-owned land after construction—up to 450 housing units and 70,000 gross square feet of retail space. While transit-oriented development is hardly the entire answer to Seattle’s housing crisis, building transit around stations is a must-do; in South Seattle, where Sound Transit failed to plan for housing two decades ago, the sparsely populated light rail line represents a series of missed opportunities.

A similar price convergence is also occurring between above and below ground options in West Seattle, where stations are planned for the Junction, the Avalon area and North Delridge.

While a long-requested tunnel route to preserve views and “neighborhood character” from the West Seattle Golf Course to the Alaska Junction—estimated cost: $1.7 billion—is still much more expensive than the two elevated options, which are priced at $900 million and $1.3 billion, respectively. But a shorter tunnel route that would head below ground after the Avalon Station is now estimated to cost $1.1 billion, less than even one of the above ground routes.

Locating a station here at Alaska Avenue and Fauntleroy, one of two preferred alternatives identified in the DEIS, offers less potential for transit-oriented development than building at 41st or 42nd, while also displacing a Safeway.

At the Alaska Junction, future transit-oriented development hinges more on the location of the station than on whether the line is elevated or buried. Stations at 41st or 42nd Avenues SW have the potential to create slightly more residential units and commercial space on leftover Sound Transit land than if the station is further east. Any kind of station on 41st Ave.  offers the best bus connection for what will become a terminus station, according to the DEIS.

While laying tracks underground minimizes construction impacts on the surface and usually displaces the fewest businesses and residents, it doesn’t always lead to a better experience for future riders. This is especially true if the journey out of these deep stations or between lines becomes its own leg of the commute.

At the new Westlake Station downtown, Sound Transit plans to bury the train platform 135 feet below the surface regardless of which alternative the board chooses—more than twice the depth of the existing station. The agency estimates it would take most riders three to six minutes to get from the street to the train platform —two escalators or two elevator rides, or a mix of both (plus a stair option on the last leg), according to the agency.

Expect another long ride to the platform at the Midtown Station at Fifth or Sixth Avenue at Madison St. downtown, which is likely to be buried even deeper: Between 140 and 205 feet.

One proposed station in the Chinatown-International District would be 190 feet underground  That’s an estimated 3.5-minute elevator trip to the surface, which could lengthen depending on the size of the crowd waiting at either end. By 2042, not long after the station is set to open, those lines could get quite long during peak hours, with between 30,100 and 34,200 riders expected to board there each day. For comparison, the Beacon Hill Station—also with elevator-only access —is buried about 160 feet underground.

With deep tunnels also come longer transfer times. Westlake, the CID Station, and SoDo will be major transfer points between the lines.

Opportunities for shallower stations are limited, said Rachelle Cunningham, a spokesperson for Sound Transit, due to soil makeup and existing infrastructure.

“We need more explanation from them why it’s so deep,” said Ben Broesamle, with Seattle Subway. “Light rail needs to be competitive with driving, and deep stations just add to the commute time.”

The Chinatown-International District is closely watching the placement of the route as the area faces a messy years-long buildout for the second station built to serve the new light rail extension. The subterranean station could go under Fourth or Fifth Avenue, and Sound Transit is studying both deep (190-foot) and shallow alternatives.

Placing the station under Fourth Ave would lessen the impact to the neighborhood during construction, as opposed to building one block to the east, according to leaders in the CID and Sound Transit.  It would also offer better integration with Sounder and Amtrak trains and with the major bus corridor along the avenue.

However, this option would take the longest and is also the most expensive alternative, because it would require rebuilding a viaduct just east of Centurylink Field, leading to a years-long street closure of the street. On the other hand, rebuilding the viaduct now could save the neighborhood a future mess by replacing the aging infrastructure as part of the light rail project.

Rebuilding the viaduct to accommodate light rail would also narrow the roadway from six to four lanes, according to current plans. This redesign of the wide avenue between Union and King Street stations could be a catalyst for activating the space around the two stations.

While a station on Fifth would make for the quickest transfer between light rail lines, it would also seize some land in the Seattle Chinatown Historic District. One station entrance would be just steps away from the Chinatown Gate, according to the plans.

Sound Transit is accepting comments on the DEIS at until April 28. The West Seattle segment is set to start operating in 2032, followed by the Ballard route in 2037 or 2039.


4 thoughts on “For Seattle’s Next Light Rail Alignment, Sound Transit Weighs Short-Term Impacts Against Long-Term Gains”

  1. An unstated alternative to third party funding is delay; ST has used delay in the past. The piece described some deep station options with longer access times; the ST ridership modeling does not seem to be precise enough to measure that travel time difference; we hope the ST board can think like transit riders and appreciate it. ST might also want to slide several stations along their alignment to provide grade separated pedestrian crossings of busy arterials (e.g., West Dravus Street, Elliott Avenue West, Delridge Way SW, 35th Avenue SW). This may also bus routes from deviations; that will cost through riders minutes as well and degrade the Link-bus network attractiveness.

  2. The initial planning for the station at 20th only considered an east-west station, with a tunnel to the west. This needs to be rethought.

    It is quite possible that the cheapest way to cross under the canal is to the east (around 14th or 15th). At that point, the train could curve, and approach 20th and Market. There are several options. It could approach at an angle (parallel to Leary). It could run east-west under Market. It could run one short block to the north, at 56th (this is a fairly detailed proposal: These are options that should be studied.

    An alignment like this would have another advantage: the station could be used for a future east-west line from Ballard to the UW. It isn’t just the tunneling that costs so much — so do the stations. Having a future line built for that purpose would substantially drop the cost of the future enhancement. Since this would be underground, the line coming from Interbay could also be extended north (it would just curve).

    These ideas should be studied. It is possible this could delay construction, but I doubt it. It will be a very long time before they start work, and the section to Ballard will be done last. Once a line is done we are stuck with the decisions that are made. We should do it right, even if we spend more time planning.

  3. Great article, but I disagree with this:

    “The 14th Avenue location provides better transfers between buses and trains than alternatives on 15th Avenue.”

    That is simply not true. Consider the two main buses in the area, the 40 and the D. The D will be truncated. It won’t go over the ship canal. It will run down 15th to the station. Then what? The obvious answer is to simply turn west, and layover by the 44. This gives people along 15th a connection to the heart of Ballard. A station at 14th wouldn’t offer that. The bus would turn towards 14th, and either layover there, or double back (delaying riders). With the D, either station requires a detour. The bus would need to stay on Market longer (either to 14th or 15th) before turning south to Leary. Using 15th creates less of a service hole. In terms of bus integration, the order is clear. 20th is best, 15th second best, and 14th worst.

    The same is true from a pedestrian standpoint. The area around 14th has developed, but not to the same level to the west. East of 15th, the development is centered around the arterials (15th and Market). Everything else is town houses. These simply have fewer people. These could be converted to bigger apartments, but that isn’t likely (these are relatively nice, and development generally leapfrogs, from a small house on a big lot to a big apartment). If you are interested in reaching the most people, 20th is the best, followed by 15th, followed by 14th.

    The same is true when it comes to people visiting the area. The cultural heart of the area is to the west. It is also where most of the jobs are (you’ve got the hospital, and a lot of retail). Again, the area to the east is growing (with lots of wonderful breweries and several restaurants) but it is nothing like the area to the west. Nor will it ever be. The west is more attractive for historical reasons (it has better bones, so to speak). The area to the east also has a lot of industrial areas that simply won’t change (that exists to the east as well, but farther away from Market).

    Building a movable bridge is not much harder than building a very high bridge. It is quite likely it would be better for riders (closer to the ground). It would be much higher than the regular bridge, and open rarely. It wouldn’t open during rush hour, and a bridge operator would time the bridge opening to the big gaps in train travel. It is quite possible a regular rider never experiences a delay, while on the weekend someone might get delayed a minute while a tall ship goes past. This is way better than the day-to-day delay of a long trip up the escalators (that we hope are working).

    But again, 20th is best, 15th second best, and 14th worst.

  4. The plentiful new development around the Othello Station was a opportunity taken, not missed. And more is to come. Several of us at the Othello Station Community Action Team have helped make this happen.

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