The Sound Transit Board just voted to pass the ST Express 2026 restructure, which will be implemented this fall. There are little or no changes from the last proposal. The vote was unanimous.
Until then the ST Express routes will remain unchanged, even though Crosslake Link will open in two days and Federal Way Link opened last December. ST says this is to provide “resiliency” through the World Cup period. I take this to mean if Link breaks down or gets overcrowded during the World Cup, these routes will remain as a backup, and the routes are widely known so residents can help visitors find them and tell them when they run.
There was extensive public testimony at the beginning of the board meeting, though most of it wasn’t about ST Express. The meeting livestream should be on ST’s YouTube channel within a couple days. I listened to bits of the testimony: most of what I heard was advocating for ST3 Link extensions not to be dropped, and there were a few ST Express comments.
We have reservations about parts of the restructure, missed opportunities for further restructuring, and the way public input was handled. The online survey had no text field to suggest changes to other routes or other alternatives for these routes. I sent my feedback in an email to ST, but most people wouldn’t think of that or get around to it or realize other changes were even possible.
More below the fold.
In the Eastside, ST’s major change is a new 556 replacing the current 550, 554, and 556. It will run run every 15 minutes daytime from the Issaquah Highlands P&R to Bellevue Transit Center, serving local stops on Gilman Blvd and Bellevue Way. This is good, as it will improve connectivity between Issaquah and Bellevue, and between Issaquah and Seattle (via a transfer at South Bellevue station to Link): 15 minutes is better than half-hourly. Metro also plans additional 15-minute express service between the Issaquah Highlands and Mercer Island station (bypassing central Issaquah).
Also in the Eastside, routes 542 and 545 will not change. 10-minute express service on the 545 between Redmond and downtown Seattle seems excessive with Link running in parallel. I’d rather see all or some of the 545’s hours shifted to route 542 between Redmond and UW, and to other routes.
In the south end, ST keeps the 577, 578, 590, 592, and 594 unchanged, to mitigate Link’s longer travel time to Federal Way. The 574 will increase to every 15 minutes daytime, and will terminate at Federal Way Downtown station and Lakewood (Sounder) station. It will no longer serve SeaTac or the Lakewood Transit Center. I’d like to see the 594 and perhaps the 590 and 592 add a Federal Way stop, delete or reduce the 577, and truncate the 578 at Federal Way. That could potentially serve more people more frequently and use bus capacity more efficiently. And Lakewood Town Center would be better than Lakewood station because it’s closer to more pedestrian destinations and homes. But ST said no, so it’s not happening.
In Seattle, Route 522 from Woodinville will switch from Roosevelt station to Shoreline South station to prefigure the upcoming Stride S3. This will lose service in Lake City, and make the connection worse between Lake City and Roosevelt, and Lake City and Northshore cities. Future Metro route 77 will backfill service between 125th and Roosevelt station, but the stop will be further away from the center of Lake City. With Metro’s 372 going away, getting from Lake City to Kenmore will require a transit at 145th, and the stops will probably not be as close to each other as they could be, or people may even end up backtracking to Shoreline south station and back (or not riding transit at all).
There are other changes in Snohomish County and elsewhere.
ST will add three new night owl routes from Everett, Redmond, and Lakewood to downtown Seattle. While these are overall good, they serve the suburbs but bypass southeast Seattle, Capitol Hill, and most of north Seattle. ST says Metro provides night owls there, but will there be timed transfers? ST could extend the expresses to Capitol Hill station, since the nightlife there is a regionwide draw and where a large chunk of the night owl ridership comes from. But it didn’t.
STB’s Alex Kvenvolden proposed an alternative showing how adding 10 minutes of travel time to ST Express routes could bring in a lot more trip pairs from more areas and higher frequency, benefiting passengers overall.
So that’s your ST Express for the next few years.
In the powerpoint slide linked at the top of the article, it shows the Redmond overnight route going to Marymoor Village after DT Redmond. Is this new and changed? If so I’m very glad. Marymoor Village is right there and has a giant parking garage with lots of apartments nearby with no other bus service, so it would be a shame to skip it.
I noticed that in the map. ST may have gotten a lot of flak about leaving out Marymoor Village and its P&R. I can see people from Sammamish and elsewhere wanting to take Link from the MV P&R to an evening activity and be able to get back to their car afterward. And the inverse routing is probably so the bus can stay on 520. So hopefully the line on the map really means that.
I felt that what they should have did was for the route 542/545 should be consolidated into a new route 543 which was serve downtown Seattle to Redmond via South lake Union and also serve the montlake freeway stop on the exit what’s the to existing evergreen point and Clyde hill and serve South Kirkland park and ride and continue on regular route as a 545 to Bear Creek Park and Ride with unchanged stops. That’s what sound transit should have considered instead of taking things so lightly as they should have thought.
Metro was going to have a peak-only route to SLU replacing the 545, but it was withdrawn due to low ridership forecasts.
Ok. But Another Things Is Have The Route 545 Re-Routed to go in South lake Union And Downtown
I also noticed they’re adding a Judkins Park stop to the Redmond overnight route but my question is… How is it going to serve it? Will it stop at Rainier and Charles like the 554 does or what? Do stunts around the station just to get on/off the I-90 bridge?
I guess it doesn’t have to be exactly at Judkin Park Link station as long as it can transfer 7.
Yeah, they are similarly calling the 45th freeway flyer stop “U-District,” though it’s quite far from the actual station.
All we know is what’s in the presentation. We can’t say how it will go, just guess how it could go.
What’s the point of keeping 566 running to Redmond Tech all this time? 566 has been very underutilized north of Bellevue for a while.
What’s more needed are limited 556 trips continuing running from/to U District to relieve 270.
We’ve been telling ST to truncate the 566 ever since the 2 Line Starter Line started. It has always said it’s out of scope for these restructures, and said no more than that. Possible reasons might be (A) ST believes a transfer would cause unacceptably long travel time for Kent and Auburn residents, or (B) it belongs in an Eastern South King restructure like Stride 1.
Even if it’s in the Stride restructure, if it terminates at the future Renton TC, it would be a 3-seat ride from Kent/Auburn to Microsoft. So ST would have to either accept that or have it overlap Stride to Bellevue TC.
It’s not just about service hours, it’s about reliability of Bellevue->Renton/Kent/Auburn trips in the PM direction. If the bus begins its route at Bellevue TC, it’s going to show up on time. If the bus begins its route at Microsoft, it has to sit in traffic through the 520/405 interchange to get to Bellevue TC, so it could be anywhere from on-time to 20 minutes late, depending on the day.
566 would probably overlap Stride to Bellevue, but skip Renton.
Then that way it can terminate in Bellevue TC. The saved time skipping Renton justifies the extra transfer time.
I do agree with asdf2. The transfer actually saves a lot of time and adds more trip possibilities. But unfortunately ST may have heard negative feedback against the change and don’t want to “disappoint” riders.
That’s why skipping Renton during a Stride realignment is the best thing they can do.
They have 566 operate to Bellevue (skip Renton during peak), then add a new all day route between Puyallup/Sumner and S Renton, so riders can transfer to Stride.
Skipping Renton is an interesting possibility I hadn’t heard of, and maybe ST hasn’t heard of. With Stride 1 serving Renton-Bellevue there’s no pressing reason for the 566 to do the same. At the same time there’s also Auburn/Kent-Renton, where people might want something faster than RapidRide I.
It also raises the interesting question that Renton wouldn’t have a one-seat ride to Redmond Tech but Auburn/Kent would. That could be justified with the longer travel time from Auburn/Kent, but conversely, Renton probably generates more ridership that wants to go to Redmond Tech.
asdf2,
The only reason that I can imagine why they are not interested in truncating 566 is that 566 runs have to be filled by 545/542 finishing in Redmond for now. In that case, making stop at Microsoft or not makes little difference. It get stuck on 520/405 even if it runs deadhead from Redmond to Bellevue.
“why they are not interested in truncating 566 is that 566 runs have to be filled by 545/542 finishing in Redmond for now.”
What does this mean?
“They have 566 operate to Bellevue (skip Renton during peak), then add a new all day route between Puyallup/Sumner and S Renton, so riders can transfer to Stride.”
When the 167 BRT is implemented in the future, it is very likely that there will be no 566.
I think big part of 566’s role north of SR 167 is like a backup to 560. When I took 566, I saw most people boarding from Bellevue TC got off before S Renton. After 566 exited I-405 at Southport, another group of people heading to destination along SR 167 freeway started boarding at several Renton stops.
Few people actually go from Bellevue to Kent/Auburn by 566, but this is just single observation by me.
Mike,
What I was trying to say is maybe 566 runs are filled by vehicles just finishing at Redmond (like Route 545).
If the vehicle filling for 566 trip always have to run deadhead from Redmond TC whether 566 starts at Redmond Tech or Bellevue, the service hour saving could be little when the Redmond Tech-Bellevue TC part is truncated.
“When the 167 BRT is implemented in the future, it is very likely that there will be no 566.”
I’m not familiar with a gelled 167 BRT plan. What is it? Will it become Stride 4 or will it be less frequent? Will it stop in the 167 median or go by a Sounder or even Link station at some point?
I suspect that ST will make further ST Express changes as Stride projects get completed. The large number of routes left alone in this particular service plan is probably not a guarantee that the ST Express route will exist in another five years. Stride will be very costly to operate (even though it’s relatively cheap to build compared to other projects), so ST may have to shift resources towards running it.
And I think is healthy to take a wait and see attitude about demand. The new 405 Express Lanes are a big change to freeway flow — and that’s on top of Stride starting to run in a few years.
ST2 Link with ST3 Stride fundamentally change the long-distance transit network in coverage, frequency and span of service hours. Peak-only ST Express or Sounder runs may continue to be useful, but that will only be known over time.
It get stuck on 520/405 even if it runs deadhead from Redmond to Bellevue.
Yeah, I was thinking it is something like that. The bus has to be moved from one place to another. It might as well pick up riders between the two spots (instead of deadheading). Then again, it might just be inertia. The 586 should have been eliminated with Northgate Link. That was a while ago. But now they are getting rid of it — seems like the timing is arbitrary.
If the 566 skips Renton, isn’t it the 567? The 567 did OK (for a peak-only ST Express bus) until the pandemic. Then ridership collapsed and they never brought it back. I could see them restoring the old pattern. Run the 566 all day. Run the 567 during peak. That is when you get the most benefit from skipping Renton (you get to take advantage of those HOV ramps). It is also when you have enough riders going from Kent/Bellevue to justify skipping Renton. Riders can get a fast commute during peak and still get home (a little slower) midday.
I think everyone assumes that when Stride 1 opens, the 560 will go away. When that happens, the 566 will help reduce the sting of the routing in Renton. The 566 runs through Renton — Stride will not. Thus riders in Renton heading to Downtown Bellevue will just switch to taking the 566 instead of the 560. Hopefully it will run often enough to make up the loss. Otherwise Renton is screwed (again).
Few people actually go from Bellevue to Kent/Auburn by 566, but this is just single observation by me.
I’m looking at old data so things may have changed, but from what I can tell, Bellevue to Kent/Auburn accounted for about a third of the ridership of the 566. The 566 picked up about 300 riders in Kent/Auburn. About 100 riders got off the bus in Renton. It is impossible to tell the exact trip pair since some people are just riding the bus within Renton but it looks like about 200 people were going from Kent/Auburn to Bellevue. Of course the 567 was almost entirely Bellevue to Kent, and it had another 300 riders. So if you count that, it was about half the 566/567 combination. This is all one direction (so double it for the actually daily ridership). With the 567 gone, my guess is the Bellevue to Kent/Auburn combination makes up a higher portion of the 566 ridership (about half?).
“When the 167 BRT is implemented in the future, it is very likely that there will be no 566.”
There is no 167 BRT, just the vague idea that there might be something in the future. It’s like when DSTT was built aspiring to future rail, but they had no idea if, what, or when.
WSDOT’s 167 master plan that’s being decided now has provisions to be forward-compatible with BRT if that’s pursued someday.
At minimum ST would have to design a route concept, and we would vote on it in ST4, and it might open in the 2060s or 2070s. A person turning 18 now would be 48 or 58 then, so it’s not anything relevant to the first 2/3 of their career life. They’ll still have to take the 566. That is, if commuting to jobs in Bellevue/Redmond is still such a big thing then, and if they still pay enough to make it worth it to go that far. If people are starving and can hardly keep the lights on, and we can’t afford to operate transit anymore, and they’re no longer living in Auburn houses but homeless tents, and big heat waves burn out agriculture and there are no immigrants to harvest it, then having a fat high-paying job in Bellevue/Redmond may be a pipe dream.
“At the same time there’s also Auburn/Kent-Renton, where people might want something faster than RapidRide I.”
The 566 is peak only, so I thought a Puyallup to Renton all day express is the best solution.
The 566 can just skip Renton (use the HOV flyover for something!) and zoom to Bellevue. Much faster trip. And they can now afford a transfer to the 2 Line with that saved time.
“ST2 Link with ST3 Stride fundamentally change the long-distance transit network in coverage, frequency and span of service hours. Peak-only ST Express or Sounder runs may continue to be useful, but that will only be known over time.”
ST Express was always intended to be an interim service that would be replaced by high-capacity transit (Link, Sounder, Stride) in the future, except in peripheral corridors too small to get any of those. So Stride 167 would be a natural evolution in that corridor.
Sounder South will still be useful because it gets from Auburn to Seattle in 30 minutes. The 578 takes 45 minutes. Transferring to Link at Federal Way or Auburn will take longer than that. Stride will not go from the Green River Valley to Seattle.
Sounder North is only competitive to Edmonds and Mukilteo. Most of those cities’ population live east of the station, downtown Mukilteo is tiny, and Whidbey Island is outside the ST tax district. Sounder or Link from Everett will take about the same time, and Link will have capacity for all 200 of Sounder North’s passengers. It would be more cost-effective to terminate Sounder North now ten years ago and put the money into replacement express buses and Snohomish’s Link dream.
The Auburn Kent market a faster and reliable service; it is Sounder. A truncated Route 566 could meet Sounder at Tukwila.
ST did not include Route 566 in the ELC project, so it is no surprise riders did not comment on it. A shorter Route 566, at both ends, could have more trips are shorter waits for the same buses and hours.
“There is no 167 BRT, just the vague idea that there might be something in the future. It’s like when DSTT was built aspiring to future rail, but they had no idea if, what, or when.”
I meant to address SKR’s comment about a route from Renton to Puyallup and the word “167 BRT” came to my mind.
167 BRT is decades a way, but an all-day SR 167 route It can happen faster than an Stride style BRT. SR 167 doesn’t have the kind of urban land use Bellevue has wrapping around the freeway, so inline stations don’t make sense anyway.
Eventually they are gonna truncate more Pierce County service. When they do that to 578, they should just make 578 the SR 167 all-day service from TIBS to Puyallup. That can replace 566 completely if they want.
With the 2 Line opening up there might be less demand on the 270. The 566 should definitely be truncated though.
There’s several factors affecting the 270:
– Travel time may be longer or shorter than the 271, commentators disagree.
– Bellevue Way has continuous apartments along it, so new riders.
– Link’s 8-10 minute service will be a godsend during the 270’s 30-60 minute periods.
– People going to Roosevelt or further north, or to Capitol Hill, are better off on Link.
Yeah it’s hard to say before it opens. I’d expect it to take about as long as the 271 and the Bellevue Way segment to do reasonably well. I think the routing is faster but it will actually have to stop on Bellevue Way to pick up riders. The Medina routing rarely stopped before 100th.
I have read the debate on the 270. Based on my analysis of the proposed route, I’m fairly certain it will be slower.
The slowest portion of the existing 271 is around the Bellevue Transit Center. The 270 makes no improvements to it.
The 271 significantly picks up speed after the mall and QFC, heading into Medina. This is one of the faster legs of the ride besides the freeway.
If the route goes through Bellevue Way, I assume it will be roughly 5 minutes slower. This is because more people will be picked up (which is good – it just slows down the trip from the TC) resulting in more stops, and Bellevue Way experiences more traffic and has more signals. It would also add freeway station stops, and travel a longer distance due to the shape of SR 520.
I think considering how Bellevue’s transit is evolving, we should strongly consider bus lanes or at least TSP. The buses don’t come that often but TSP can to time the green lights with the buses would seriously improve their performance within Bellevue downtown. I think it’s something Bellevue transit users and advocates should push the city to implement.
I think with no stops Bellevue Way would be a minute or two faster, but the additional riders that I assume will board on Bellevue Way will definitely slow down the bus. Yeah maybe in the ideal case the 270 is slower because it has to pick up so many riders, hah
I would love to see some BAT lanes in Bellevue but the city seems pretty politically resistant to them. For example the K line is getting watered down a bit (BAT lanes removed) due to meddling by elected officials. On the other hand I’ve heard that Bellevue is very good at signal management, so maybe some level of TSP is possible.
“I’m fairly certain [the 270] will be slower. The slowest portion of the existing 271 is around the Bellevue Transit Center.”
I think Bellevue Way has a higher speed limit than 8th/12th and 84th, 35 vs 30, and it has four lanes so competing cars can use the other lane.
Route 249 served Bellevue Way between fall 2011 and ELC. It was reduced to hourly midday headway in reductions of fall 2014. Metro did not fill that service hole; Route 249 was not in the scope of the north Eastside project, fall 2020. The apartments on Bellevue Way could be served by a route with a different orientation. Route 270 will have less peak service than Route 271; Route 556 will be gone.
If 270 will be fully operated by 60-ft, it could be one thing it gains from this restructure.
I just don’t think it makes sense for this route to operate in mix of 40/60 ft buses if they can only do 15-minute headway.
Metro doesn’t have enough 60 foot buses. It’s a persistent issue on Route 255, and also peak hour buses where they have to substitute Rapid Ride or ST Express livery buses to make up for that deficit.
So I highly doubt they can procure enough 60 footers to operate the 270. I’m also guessing they plan to through route the 220 and 270.
As for the Bellevue Way comments, even without stops, Bellevue Way would probably be slower than Medina without stops. The reason is because Bellevue Way has a lot of traffic lights and congestion can get heavy during peak. Even if the speed limit is higher, on the Medina length, you’re always able to move without much stopping or blocking you. Bellevue Way won’t prove the same.
That said, traffic signal priority will do a lot to improve any bus running on Bellevue Way and any other city street. That should be something that is done.
It blows my mind that they’re proposing running all the routes through Downtown Seattle overnight but not extending the Federal Way route just a bit further to Capitol Hill before ending.
Do ST service planners understand Seattle night life at all? Why are they skipping the third busiest station in the system?
I get that they say that Metro is running in Seattle — but Capitol Hill is a regional nightlife draw. It deserves direct overnight service. Plus there are lots of flight attendants that live near the station.
If you only counted boardings after 11pm, I bet Capitol Hill would rank as the busiest station in the whole system. So yeah, excluding it from the night owl is dumb as heck.
Sound Transit seems to have focused on efficiently serving as many stations as possible rather than as many riders as possible. I predict SeaTac Airport will be the most popular night owl station, and riders will quickly start complaining about having to transfer at seedy downtown stops.
It’s serving freeway stations in the north and south and the SODO busway, like ST Express traditionally does. The other Seattle stops are regional centers (U-District and Northgate), which it politically must serve. On the Eastside it’s different because much of Link is not near the freeway or there’s no freeway exit.
Remember, the suburban subareas are paying for ST Express. North King isn’t. So it goes where suburban taxpayers live and a few logistically-convenient stops in Seattle. As for suburbanites wanting to go from Capitol Hill late night, the politicians haven’t thought that far, and most suburban constituents haven’t either.
The key is timed transfers between the 3 ST night owl routes somewhere in downtown Seattle (and perhaps work with KCMT to time coordinate with their night owl service, the old 80’s series Night owl routes did coordinate). Traffic at that time of the night is very light, so schedules should be able to hold.
The combination of skipping all of South Seattle and Capitol Hill will make the night owl service pretty middling. Average transfer times to half hourly or worse night owl buses are 15 to 30 minutes. That’s a horrible rider experience, and only the dedicated or choice less will take it.
The 570 needs to do one or the other, and ideally both. But I guess ST is constrained by Pierce Transit operating the route so a marginally faster and more frequent 124 (with fewer intermediate stops) is what we get.
It’s just baffling to me.
It appears the South night express route will not be serving 10th & Commerce as originally proposed.
Considering the fact there aren’t any night owl routes that I’m aware of between Downtown Tacoma and the Tacoma Dome this seems like a much bigger loss of potential and very disappointing.
There was almost no discussion from ST or anyone else about this. Tacoma Dome has terrible walkability, density and transit connection even during peak hours. Let alone at 2am. Huge miss and I’m curious who could even justify the reason it was removed.
Probably related to Sound Transit’s unhealthy obsession with treating Tacoma as nothing but the fancy Pierce County transit hub they built rather than an actual city that should probably be receiving better than what it currently has.
That’s my best guess aside from anything even more pessimistic or ignorantly naive.
You realizes who sets Sound Transit’s direction for Tacoma? It’s Pierce boardmembers, the city of Tacoma, other Pierce city officials, and the Pierce County government. They tell ST what they want, and the rest of ST usually goes along with it. So if you don’t like what ST is doing there, blame them, and elect or recruit some better officials in Pierce County.
@Mike Orr
Sorry Mike, I thought it was customary to blame Sound Transit for everything here as a boogeyman. I was trying to be liked again.
It’s not just you, Bernie and others blame Sound Transit for how poorly it serves Pierce County. But those are all because that’s what Pierce County officials wanted and insisted on. It needs to be understood why Pierce is getting what it’s getting, and how it could have gotten something different, and how it could get something different now and in the future if it changes its mind.
Well, at least ST Express 515 and 586 are going away, finally.
The CEO could suspend 586 service after spring commencement, since it does not serve Seattle Stadium, and therefore adds no resiliency for the World Cup. Indeed, continuing to run it removes some buses and operators from being available for World Cup resiliency. It is also kinda funny that riding the 1 Line from Federal Way to UW (a 62-minute trip, before counting station ingress and egress) was not listed as an alternative.
There is still time to repair Metro’s restructure by adding a lot more 270 service (much faster than taking a 32-minute 2 Line trip the long way around, not counting station ingress and egress) and pointing routes 67 and 75 to Pinehurst Station. It is nice to have the new route 77, but under a sane route restructure, the 75 has 125th to Pinehurst covered. The 77 can keep heading north to 145th and possibly further.
The 586 never made since after U Link.
A SODO transfer was always the faster because of traffic on the Ship Canal bridge.
If the SODO busway closes, a Chinatown transfer wouldn’t be bad either. But add 3-4 more downtown stations, then maybe the 586 was faster.
Why would ST ditch Lakewood Town Center and serve only Lakewood Sounder station? That’s on the other side of the freeway from where most of the people live and what passes for density is. It’s a long walk from Lakewood station to where many riders would live. I don’t think the Lakewood station area has hardly anything.
Is Pierce Transit modifying routes to accommodate the change? Not sure of the run times or the consistency of the 3 route – or other PT routes that travel near both LTC and Lakewood Station.
I understand why the 592 doesn’t make the “jaunt” west into Lakewood as primarily a commuter bus, but the 574 moving to Lakewood Station only would really require some thought to get airport/local riders closer to residential Lakewood.
The ST restructure and night owl service in Pierce is just bizarre. The serve parking garages only. Lakewood station. Lakewood park and ride. Tacoma Dome. Ain’t no residences or jobs to speak of at any of those locations. Just car storage.
Yesterday, I testified over Zoom in the morning service change hearing. My concern was the forced transfers for Issaquah riders. This would not been an issue if the 2 line had 4 car trains, but ST does not have enough LRV’s for 4 car trains and 2-3 cars on the 2 line will be the norm for awhile (so will the smaller consist be able to accommodate all, especially during peak periods) I recommended to keep the 554 during peak hour/peak direction only initially until ridership patterns develop and when the 2 line has enough capacity to accommodate all the forced transfers (it is not simply Issaquah but other areas too). A current example of this, is Everett with the 510 being the peak backup and 512 providing the all day service. I just hope my prediction is wrong and when it comes to late August, that the 2 line can accommodate all. If not, there will be some angry riders.
Isn’t that shortage due to the OMF-East not connected to the mainline? I thought once Crosslake is open, ST will be able to go back to 4-car trains?
There are a number of sequencing issues.
The recent initial train set shortage was due to the capacity of the Central OMF until the East OMF could be accessed. That issue is now seemingly over.
The next issue is that ST underestimated the number of train cars needed to run full 1 Line + 2 Line trains when they ordered cars. That’s not a yard capacity problem; it’s a total number of train cars needed problem.
The extensions in the 2030’s if built as planned will require the third yard (South OMF) and Everett Link Extension is so long that it apparently triggers a fourth North OMF. So ST must plan for both the number of train cars and the OMF yard sizing. (It’s possible that the North OMF would not be needed or could be smaller if Ballard Link was automated with its own OMF but that’s not been studied.)
There are several ways to operationally manage a crowding problem. It looks like the highest load factors on Link will however remain between Downtown Seattle and UW even with both lines running on that segment. I don’t think that crowding across Lake Washington will be bad with three car trains (as a three car train carries about as many riders as what five articulated buses carry). And as long as ST avoids dispatching a three-car train after a service gap even the North segment may be fine. (Ideally, a three car train should be close on the heels of a four car train to avoid accumulating heavy loads.)
Careful analysis of train loads — even down to particular individual train runs — could help ST figure out how long each train should be. One would hope that they’ll be doing that. (It’s why it’s a good idea to have operations managers with many years of crowded rail transit experience elsewhere. Otherwise it’s OJT for a few years until the managers finally figure it out.)