Busway for SeaTac Airport

54 Replies to “Busway for SeaTac Airport”

1. I don’t see how using an elevated busway would save money relative to a people mover. Is they were reapportioning existing road space to the busway they’d save money, but short of that it seems like this won’t reduce their costs.

   1. Agreed. Welcome to the Northwest: We build rail where we should have buses, and buses where we should have rail.

2. I am uninspired by this costly expansion. It doesn’t look like it does much for anyone other than add gates that look like a real hassle to get to. Outside of bringing the path to Link more indoors with a moving sidewalk, it doesn’t do much for transit — and that component has been in the works for several years now so it’s not a novel proposal.

   1. Me either. It’s going to be years of painful construction. And, for all the port’s greenwashing, the additional flights this enables is going to come with a large carbon footprint.

      But, hey, I’ll take this over a brand new SeaTac-sized airport out in rural King County (as some have proposed) any day.

      1. I get the need to avoid a new airport! It’s also a big factor on justifying California HSR even though pundits often ignore that factor. California airport delays are notoriously bad. Building California HSR is better than building two new airports along with the ground transportation systems to reach them because of how distant they would be.

3. The term busway may be misleading. Surely a closed system without people walking across the lanes is a perfect setup for automation. Maybe the generic term is used to give the Port leverage in bargaining for the right automated technology.

   I’m also surprised that it stops where it does. It seems to me that it needs to go further to the South terminal with its international flights.

   1. yes, I suggested it would follow the current shuttle bus route on the west side of the parking garage and essentially circle around the whole central garage back on the eastside of the garage before joining the busway again. And then you might as well build a people mover which can run at higher frequency at all times a day.

4. Just build a people mover, it seems like they’re overcomplicated things for a more cost effective solution for more or less the same cost

5. They need to include an airside connection to the new terminal, whether it be an extension of the North Satellite train loop or a new train route. Having all gates connected airside has been a plus for SEA and it would be unfortunate to lose that access with the new terminal.

   1. For the next phase one will be able to walk from the north end of the center terminal to the new terminal (gate side)

      I surprisingly did not find any documents or proposals about extending the yellow north/south line people mover but it generally looks possible to do so

   2. The SEA Underground has 3 lines: 2 loops and a shuttle linking the loops (cross platform transfer). Each loop line serves a satellite terminal but the shuttle links north and south points of the airside of the main terminal. Would think this shuttle train line could be extended north to the new terminal for an airside link.

6. “[The SeaTac garage is] the country’s largest parking structure under a single roof.” (in the “sheltered walk” link). Wait. what? Don’t most major airports in the US have as many parking spaces?

   1. Most of the other airports have it as separated lots or multiple garages. SeaTac has it all under one roof.

   2. Then it’s an unimportant detail, and it’s not worth comparing individual parking structures. Yet the Stranger wrote it as if it mattered, and the World Atlas looked at individual lots or garages as if the lot next to them on the same site didn’t exist. What matters is the total amount of parking at a site.

      1. It’s obvious why it matters.

         PNWers are Rain Wimps.

         Can’t get that Gor-Tex wet!

      2. That article was just pointing it out in the context of post covid where there were a lot more travelers and some airports were running out of parking. It wasn’t really that big of a deal as both of you noted as there was overflow parking in third party lots — and that temporary increase of (business? vacation travelers?) has went back to normal.

         > World Atlas looked at individual lots or garages

         They were just judging the building itself. It’s actually a bit of a downside as well. It’s why the building is so hard to retrofit with the new light rail walkway. If it was a couple separate buildings it’d be a lot easier.

7. Does this post imply that the ped bridge for the STRIDE bus at TIBS is actually happening? I thought that bridge was cut to save money, and the buses would have to detour into TIBS instead (like RapidRide F does today).

   1. The tibs in freeway median station is not being built because the cost of rebuilding the water culvert for fishes is too high. Sound transit has deferred the freeway station to the future — but no set date

   2. I don’t see how this article implies one TIB configuration or the other.

      During editing I suggested the airport shuttle could be extended to TIB station itself and layover there. Then there wouldn’t be the dilemma of whether it’s hard or not to walk from the station to the shuttle, and whether you’d have to walk across the freeway or go out of your way to get to a freeway crossing. It was in later drafts of the article but didn’t make it to the final. I’d suggested extending it at both ends, north to TIB station, and south to the airport bus stops on the west side.

      1. A lot of airport passengers are using TIBS now. Having shuttle connecting TIBS definitely has a huge benefit for passengers, but I don’t think airport is interested in doing that.
         If many people are not taking Uber/Lyft at TIBS rather than airport, their TNC airport surcharge revenue will plunge.

      2. @Mike @HZ

         To clarify a bit more since it wasn’t mentioned. Most likely the elevated busway would connect to the existing rental car facility bus turnaround. That’s about 5 stories tall.

         If it was a separate bus station on to the ground or just the second floor then a street connection could probably easily be added that would connect to the tukwila international bouelvard. And then bus could easily travel the station itself

      3. Thanks. That does help, especially for folks like me who only skimmed things. It is unlikely this will become “open BRT”, but instead be a stand-alone busway.

8. I haven’t dug into the EIS but I have to wonder if the Port ever looked at just using the Link tracks with branches or sidings for the additional stops. I envision something like a new short Link line with tracks that branch and curve from south of the Airport Station into a stub at the south end, a cross platform transfer at the current Link station. a new north satellite station with platforms on the outside created by short siding tracks, and a final branch that ends at the rental cars with maybe an aerial pedestrian connection to Stride and TIBS.

   Even at just 8 minute frequencies or better yet 6 minute frequencies it would be faster than walking with bags. It may be possible to even get two airport shuttle trains squeezed in between each 1 Line arrival. A SeaTac arriving Link rider would merely have to step off a 1 Line train, wait maybe 2-3 minutes for the shuttle train right on the platform and then board that train to the next station.

   I imagine that the Port would bristle at trying to build and operate something with ST — but from a rider viewpoint the concept would enable an easier experience coming from Terminals S, A and B to Link and the rental cars compared to what’s proposed here.

   1. Apparently Minneapolis airport uses the regional light rail system for linking two separate airport terminals. When regular light rail service is finished for the night they still run light rail all night between the terminals with a shuttle train on one track. Otherwise airport passengers just use the light rail trains like normal during the day but no fare is charged. So there is a precedent for the transit system providing the airport transfers.

      1. St Louis has two light rail stops at the airport too.

         Minneapolis has a cable-pulled people mover too. The cost of cable technology can be cheaper but there are constraints. The biggest is that it’s a bit tricky to site intermediate stations.

9. I may have missed this, but is this a closed busway or open?

   If it’s open for use by transit routes, Belair Airporter, etc then I guess I could understand why it works as a busway.

   If the plan involves replicating the stupidity of the existing system, which involves having some 15 buses idling at the car rental facility between trips to the airport terminal, the busway is going to be vastly more expensive to operate than an automated people mover.

   The Kahului Airport has a people mover that is about 500 feet long. It’s about half the size of a typical airport people mover, and operates on a single track with passing siding. As the trains are very light, you wouldn’t need the substantial construction of the busway or the typical peoplemover. As they’re small, you could operate them in the existing pathway between the Link station and the airport terminal, adding one more stop and a lot of convenience.

   If they think they need more capacity than such a system could provide, then they really need a real people mover.

   1. There will be at least the closed route of the 1) North end of the Central Garage
      2) New North Terminal and 3) Consolidated Car Rental Facility

      Unfortunately the EIS is not exactly clear if other bus shuttles outside of the closed route could enter easily (I helped write the article).

      > The Kahului Airport has a people mover that is about 500 feet long.

      Ironically the other haiwaii airport, Honolulu airport’s bus shuttle system is probably very similar to what SeaTac is building. Aka the Intra-Airport Transportation Wiki Wiki Shuttle. (There are two ‘wiki’s). Difference being that hnl uses for post-security while the HNL one is pre-security.

      Below shows a map of the shuttle.
      https://www.yelp.com/biz_photos/wiki-wiki-shuttle-honolulu?select=6oBHq_Mi3d2t-HdkL4A3-A

      1. Thanks, Wesley, for doing most of research work on this article!
         I agree that the EIS is not clear on whether this is an open or closed busway. In parts it seems to imply its open to hotel shuttles and other buses (transit, charter…), but it doesn’t show where such buses would enter and exit the busway nor does it show where shuttles would turn around. If it’s an open busway, it may have some interesting applications (e.g. Stride connection). It it’s a closed loop, then a people mover should allow for simpler guideway and cheaper, more frequent, automated operation.

   2. Imagine if Stride could use this busway. It would almost be worth sending all Bellevue-Burien Stride buses on a detour onto this busway to serve the airport. An airport transit link is a huge deal for the communities served by such a line whether passengers or employees, would reduce congestion to the airport, and even increase passengers flying out of the airport (having cheap reliable transport TO the airport induces flying).

      1. Yes, that is a whole different ballgame. A completely enclosed busway rarely makes sense. Might as well make it (automated) rail. But a busway connected to the roadway has huge benefits. In this case it would avoid a transfer.

      2. For the dozenth time, when ST was designing Stride 1 it asked the community whether it should go to Burien or SeaTac. The majority of feedback said Burien. That may be because Burien has so little express service and is hard to get to, and some people go to/from Burien every day but only go to the airport once or twice a year. So all those people are the ones you’d be hurting if you rerouted Stride 1 to the airport or made it detour to the airport on the way to Burien. The public spoke and wanted a fast route to Burien.

      3. “… when ST was designing Stride 1 it asked the community whether it should go to Burien or SeaTac. The majority of feedback said Burien.“

         This is a classic case of how one defines “community” and frames questions. Few SeaTac residents will want Stride to go to SeaTac Airport. TIBS area residents will want TIBS. Burien residents will want Burien.

         And ST never asked if it should go to SeaTac BEFORE Burien. ST asked the wrong tradeoff question. It should have asked “where should Stride meet Link (TIBS or SeaTac)?” And not “where should Stride end (SeaTac or Burien)?”. I’m convinced that Burien residents would have preferred SeaTac as RapidRide F already connects to TIBS.

      4. None of that would be an issue if the pre-security inter-terminal transportation system (aka airport busway) were extended all of 700 feet further, to get to TIBS. This would provide such frequent service from TIBS to the airport there wouldn’t need to be any bus route extension.

      5. Yes, poncho suggested Stride be diverted to SeaTac. But the essence of his comment — the one I responded to — was the idea that this busway would be open. That means ST and/or Metro buses could cover it. That makes all the difference in the world in terms of this project.

         As for Stride 1, one big consideration is cost. Going to SeaTac would require a lot of extra funding. I have no idea where they would get that. Another consideration is existing ridership. About 250 people a day rode the bus heading towards Bellevue (with ridership split evenly between the stops). About 300 riders took the bus from Burien/West Seattle. Most of those were north of the Burien transit center. About 105 people went from Burien to SeaTac. Another 400 rode the bus between Renton and Bellevue.

         So basically it is a slimmed down version of the 560. Riders from north of Burien Transit Center will have to transfer. Riders from SeaTac will have to transfer. Riders from Burien will have a faster trip, but the main benefit is that it is a lost shorter, and doesn’t overlap as much with other service. It is a regional express, which means it will be fast and cheap (from a service standpoint).

         I could see it doing more, but it isn’t clear that would actually be better from a service/ridership standpoint. A lot of people will continue to have a one-seat ride. For them, the extra frequency (and in some cases faster ride) will be a huge benefit. Meanwhile, most of the people who are now forced to transfer will do so.

         If there are a lot of people who suddenly want to go to SeaTac, then Metro (or ST) could add a second bus. I doubt there will be enough ridership to justify that though.

      6. @Ross: in case you forgot, ST has chosen to indefinitely defer the online stop at TIBS. Its construction may never happen due to the safety and slope issues. ST previously cancelled a pedestrian bridge over SR 518.

         Thus serving TIBS is going to require that Stride buses go through signals. Meanwhile, the same bus could get to SeaTac Airport station and back in about the same time assuming the right turnaround — especially with a shared busway that somehow merges with SR 518.

         So why is there a substantial additional cost? For an increase of 0-3 minutes for each bus and about 2 additional round trip miles (3 miles vs 1 mile) but no signals to wait for? That’s barely. Dent in operating costs.

         If anything, it would add a direct connection between the Airport (now the second busiest 1 Line station) and the second busiest 2 Line station (Bellevue Downtown). That would add riders to Stride and reduce Link crowding in Seattle.

      7. I’m basing it on the assumption that they build it as planned (with a freeway stop at TIBS). This is the most likely (long term) outcome.

         So why is there a substantial additional cost?

         By my calculation it takes about ten minutes to detour to SeaTac (and probably more if there is traffic). The trip without the detour takes roughly third minutes.

         Assume for a second this is taken out of frequency. The plan is for S1 to run every fifteen minutes in the middle of the day. So that means two hours of service time per hour (one way). With a forty minute trip, that works out to a bus every twenty minutes instead.

         This would be if it was implemented in the long term. In the short term there are two choices:

         1) Serve both TIBS and SeaTac. This costs even more money. Maybe you can get by with twenty minute service (and fifteen minute during peak). Maybe you go with thirty minute.

         2) Serve SeaTac instead of TIBS (until they add the freeway station). This doesn’t save you any time. Furthermore, you essentially break your commitment to Tukwila. It is easy to dismiss TIBS, but it gets a respectable 4,000 riders a day on Link. It seems quite likely that there are riders in the area who are looking forward to the express to Renton and Bellevue. Now they will have to take the train south to SeaTac and then ride the bus back. Or they will take the milk run that is the F to Renton. Either way Tukwila riders would be getting shortchanged. It is worth noting that the 560 doesn’t currently serve Tukwila. It is quite possible that ridership there would be higher than SeaTac. We don’t know yet.

         It would also be weird to run the bus to SeaTac for a few years and then (when they build the freeway stop) switch over to serving TIBS.

      8. “This is a classic case of how one defines “community” and frames questions.”

         The community is the South King subarea, who’s paying for it. More people in South King wanted Stride to go to Burien than wanted it to go to SeaTac. Detouring to SeaTac would add to travel time, the opposite of Stride’s goal which was to be faster than the 560.

      9. “ Detouring to SeaTac would add to travel time, the opposite of Stride’s goal which was to be faster than the 560.”

         The required routing for TIBS adds 6 minutes according to the Urbanist article:

         https://seattletransitblog.com/2024/09/06/stride-s1-line-updates/

         Going to SeaTac instead will add 10 minutes according to Ross and I think it’s really could be 7 minutes if it has a turnaround at SeaTac Link with a rapid U-turn possible rather than the 560 path. Keep in mind that the route to and from SeaTac could easily have no signals. The eastbound route from TIBS has 7 signals as I count, with 4 being left turns.

         But more than that, isn’t it irresponsible to commit to being an albatross project if its construction is later found to be too ridiculously difficult and expensive? That’s exactly the problem with much of ST3. You guys admit that! You suggest that ST revisit things and not put knee-jerk decisions made almost 9 years ago in stone. Yet Stride at TIBS was never seriously flushed out before that dot was dropped at TIBS after a modest discussion. I’m simply saying that when a project element doesn’t work that it needs to be revisited and possibly improved. I put Stride in that category.

         See, just like DSTT2 wasn’t studied before the 2016 packaging, neither was Stride 1 in its entirety. Here’s a summary of those studies that WSDOT has posted for historical reference:

         https://wsdot.wa.gov/partners/erp/background/ERP%20150505%20HCT%20Corridor%20Studies.pdf

      10. That WSDOT study makes the planned Issaquah-Kirkland light rail line look really bad relative to BRT

10. It’s quite possible that the POS is going with the busway option because it envisions fully autonomous driverless electric buses, which would negate the need for a people mover on rails. With the right technologies embedded in the roadway (including charging), it could be quite the effective system. But I’m probably far too optimistic.

    1. Many airport people movers already are rubber tired vehicles. In other words, they already are automated buses, just linked together to form trains and with a guideway with flanges rather than a fully paved road, and current collectors rather than an onboard battery. As a closed system, there’s no reason to use standard highway legal vehicles.

       1. Exactly. They’re light because they ate protected within a reserved right-of-way, third-rail-powered, and self-guiding without complex steering! They just follow the sidewalls of the guideway.

          They already have staff who know how to maintain People Movers. WHAT are they thinking.

       2. For clarity, if ST and other carriers’ buses were allowed in the busway — and a connection to 24th were provided south of the terminal — then yes, the busway would be GREAT! If not, use the technology they already have mastered. That gives economies of scale on maintenance.

    2. A guideway is more efficient than an asphalt lane if there’s only going to be dedicated vehicles on it, and it can be smaller (thus using less materials and being less obtrusive). If it has a power wire or the power transmission is built into the guideway, you don’t need an inefficient battery just to convert the electricity to chemical storage and back.

    3. There is a brand new elevated busway in Mexico City… Trolebus Elevado. I would imagine it to be a lot like this, although unlikely with trolley buses :( .

11. I know many of you don’t support airport expansions but SeaTac is in dire need of a major overhaul of its existing terminal and an outright expansion (I also support a secondary airport but only in Snohomish county).

    Admittedly, I only glanced at the proposed renditions of the expansion. If the new North facilities have a separate check-in area, then I’d argue a fill-in station is needed just north of the current SeaTac station. That’d be a heck-uva walk with bags from the current location to the site.

12. I guess a little OT, but what’s the difference between an Environmental Assessment (NEPA, SEPA) and an Environmental Impact Statement (EIS)? And when do projects require one, the other, or both?

    1. Because there are both state and Federal laws involved, the rules are a bit complex. Something like an airport usually must comply with both.

       To make it even more convoluted, both NEPA (National) and SEPA (state) use the term EIS. Of course, because the laws substantially overlap, most EIS’ are written to satisfy both of them.

       There are plenty of attorneys who debate these things and get paid tons of money to argue what’s needed to comply. There’s a whole industry just answering this question!

    2. My understanding is that an Environmental Assessment (EA) is preliminary and not in depth. You do those first, to determine whether you need to a do a more time consuming EIS. It is common to have a Finding of No Significant Impact with an EA, which means you don’t need to do an EIS. (Unless someone sues, of course.)

       1. Yes that’s my understanding too, Ross. I’ll add that airports with passenger service likely have extra compliance concerns from the FAA that aren’t stated in State law. It usually only takes one rule at either the state or Federal level to push a project or plan into needing an EIS.

       2. Thanks. That helps. And AI agrees with you. If not for your temper I’d be suspicious. ;)

13. The only real solution is to buy out the cemetery. Then we can build a real airport not squeezed into ridiculous tiny footprints.

    1. It’s feasible but very complicated to do and can take years. Even moreso than some other slow moving redevelopment like Superfunds.

14. A people mover walkway between Link and the passenger terminal vs. the single mini-truck people mover that if you’re extremely lucky (like getting the winning lottery numbers) is waiting and empty when you arrive there. Not everybody is able-bodied! In addition, the region needs new airport capacity and that means to “grow a pair” so that the pain of air travel is shared throughout the region and not with only the Burien/Sea-Tac area. In the recently disbanded group, they released a report showing that the highest demand for air travel was in the Pierce/Thurston County area, thus that’s where a site should be sought vs. succumbing to the public and their public officials to put up barriers in the spirit of NIMBYism.

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