Credit: Atomic Taco

At the Sound Transit Board’s executive committee today, ST CEO Peter Rogoff said that Sound Transit will be the sole operator in the Downtown Seattle Transit Tunnel (DSTT) starting March 23, 2019, as King County Metro vacates the tunnel. 

Rogoff also announced that ST will run trains in both directions on a single track for a yet to be determined part of 2020, as part of East Link construction.

ST spokesperson Geoff Patrick said that six minute peak headways will remain the same after ST takes over the tunnel, but the trains will “actually be able to meet them.”

At present, bus-related impediments, like onboarding and payment, prevent ST from meeting ideal reliability standards in the tunnel. After the changeover, trains will be able to operate at higher speeds between stations, with less time spent idling between stations or lingering at the platform.

Patrick said that “there’s no way to finish construction” without the single-tracking, which will be located just south of the Chinatown/International District station. Switches will be installed in the tunnel guideway, to connect East Link’s ramp—which previously carried Eastside-bound buses into the DSTT—to the existing rail network.

ST will have to increase headways and reduce train speeds to complete the connection. 

Patrick said that ST staff are still planning the construction work, and will announce firmer plans in January.

43 Replies to “Downtown Seattle Transit Tunnel to go rail-only on March 23; CID single tracking coming in 2020”

  1. It’s good that the single-tracking happens before Northgate Link opens. I can’t imagine that the insertion of switches will take more than a few weeks. Will there still be three-car trains?

    It’s tight but probably not fatal to go single-tracking at six-minute headways. If it gets too bad, it would seem that going to eight-minute headway’s with four-car trains would offer the same line capacity.

  2. This is a real-world example of how the failure to add switches presents big problems down the road.

    We will probably have similar disruptions in SODO and at East Main as ST3 lines get built. Since the South Kirkland split is at the OMF, it probably won’t pose a problem. Those projects aren’t yet far enough along to define where switches should be.

    Are there other places that could benefit from adding switches —especially before opening days?

    1. On the other hand, Metro added tracks to the DSTT when it was first built that had to be torn out, replaced, and all the stations were reconfigured for the light rail system that exists now, One cannot reliably predict the future. Yes, the switches would likely be compatible if installed only a few years ago, but the placement of them is a different story.

    2. SLU will be on the second tunnel. If you mean SLU should have a turnback for trains not going to Ballard, it’s not designed yet so maybe it will. Has ST given any indication 8it wouldn’t? An SLU turnback would also be worthwhile in case the drawbridge breaks.

    1. A collision is highly unlikely if not impossible.

      Rail systems are almost always designed for two-way operation — even when there are directional tracks. Collision avoidance is part of that design. Operators today follow the signal blocks installed in the tunnel and only one train at a time is allowed in that block.

      Plus, this area has slow speeds anyway. Operators should be able to visually see and stop if a collision is imminent even with a train control systems failure.

      The biggest challenge will fall to the control center to stay on top of operations continuously. Hopefully, ST will add overtime for more staff. Even just a two or three minute gap can begin to clog the trains up.

    2. Link Light Rail has had to do single-tracking many times before, including after accidents and for maintenance on the 9-minute segment between Rainier Beach Station and Tukwila International Boulevard Station.

  3. Not too worried about the single-tracking. It’ll still be better than having buses in the tunnel!

    Speaking of which, this is exciting news! While it’ll be tough for some suburban commuters to switch to a slow surface line, having light rail-only tunnel operations will seriously speed up and improve the experience for Link riders. Now if only they’d put orca readers at the top of the stairs/escalators in Pioneer Square station and fix the real-time arrival signs…

    1. What real time arrival signs? ST has none. Only the stupid two minute warning. Even the “real time” signs in Cap Hill and Husky Stadium only show the scheduled times.

      1. It’s an embarrassment how ST can’t manage something so basic. Should’ve been there from day 1.

      2. The displays are there; nobody just wants to spend the money to program them properly. But converting them to REAL real-time displays is supposed to be part of ST2. As for the new ones, they showED only the scheduled times during the first year but now they’ve gotten better. They’re generally within two minutes of the actual departures, and they sometimes have irregular intervals like 2, 5, 14 or 2, 22, 32, which I suppose reflects trains being late or something. Why they’re not exact I don’t know. Sometimes I miss a southbound UW train while the sign still says 2; and last week I thought I’d just miss a train but I was able to slip in at 1 but then the train didn’t move until two minutes later. I guess ST doesn’t bother too much about exact times, just vaguely approximate. I haven’t been to London for years but it’s hard to imagine their signs being so vague. But it’s more than just the scheduled times now; they’re getting some information about where the train is. But it appears to be noisy information, like the information in Metro’s system. Buses in the tunnel also throw it off, because the system can’t predict whether a bus will open for a wheelchair in the next minute or if it will take a long time for a crowd to get in and out of it.

      3. Will there be a sign indicating the number of cars in a train, or will we just see every train become a four-car train?

      4. It is mystifying why ST cannot seem to get it together with the next arriving train times. I guess they don’t care?

      5. They say it costs a lot of money to have a contractor reprogram the displays. The displays were installed in the 1980s when they didn’t know when/if trains would ever be deployed. ST1 cheapened out and only included the 2-minute voice announcement, which I guess is cheaper, in the same way a pager is cheaper than a cell phone.

      6. Those displays in the DSTT were not installed in the 1980s, rather were part of the LINK conversion…

    2. Overall this will result in worse transit. It is important to remember why this is being done. It isn’t being done so that Sound Transit can run the trains more frequently. They can’t. They don’t even have the train cars necessary to do that. The increase in frequency along with the increase in cars was supposed to happen at the same time as they removed the buses from the tunnel. Of course it was — that would make sense. But instead, this is being done because the convention center is being rebuilt. They could have waited a few years (or simply not expanded it) but instead they just didn’t care. \

      1. It’s not just the convention center. ST is installing a maintenance turn track for East Link just south of Intl Dist that will somehow preclude buses in the tunnel. That was scheduled for 2019 anyway, so the convention center merely moves up the bus ejection date by six months.

  4. Doubt there’s ever even been a “close one” between a train and a bus at IDS- which would’ve been a lot more likely than a head-on collision on that particular piece of track.

    Leaving us to concentrate on the real intermediacy-unknown Sound to North Bend and Olympia to Bellingham wreck of everything on wheels one story above the single-track situation.

    And a caution about using the word “Challenge” in an official excuse. By some codes in the old tradition, if we, meaning our passengers and first line transit personnel receive a challenge to straighten out a disaster not of our chosing ..we get to choose the weapons!


  5. Having been both a bus (3rd Ave) and Link commuter in downtown, I can say authoritatively that the train experience is already great and that trains are already much, much more reliable than buses. I’m very concerned that adding buses to 3rd Ave (31 southbound buses in the 5:00pm hour, for example) will add significant pressure to the already overburdened 3rd Ave. I can’t understand why it’s necessary to do this right now in the midst of the viaduct demolition.

    1. We had to put DSTT through Downtown Seattle with a major building boom in progress. Which if memory serves, put all the trolleybuses down to First between Jackson and Virginia.

      We’d also been told on good authority that if we didn’t get that tunnel started PDQ, somebody already had the papers to build a skyscraper that would’ve been a permanent stake through the heart of the subway we knew regional transit would shortly need. Too bad Dr. Van Helsing hadn’t gotten back from Transylvania yet.

      My point is that very often as with the Viaduct, no one knew to the decade when that would come down, by blasting gel or plate tectonics. Was finally supposed to go away in 2012. But two ungood (Book 1984) surprises. Convention Center became too small. And seismic message said the planet needed that corridor clear. So what I’m saying is that transit needs to be ready to deal with unforeseen events.

      Most serious obstacle was that our every elected official got so preoccupied with the Metro-King County war for control that more than one critical decision went unattended, some permanently.

      For DSTT itself, its worst flaw all these years was decision that so long as everything that went in eventually came out, service was on time. Don’t know which wasted more money, turning off a fortune in signals after two weeks, or 35 years’ lost operating time re: last phrase.

      What you need to ask is why Third isn’t carrying anywhere near its max throughput right now. Remove every single car and then check. Set every traffic light to “Green Wave” for transit- meaning stops at bus stops only.

      And do what DSTT was designed to do: 31/4 = 7 “platoons” -too bad buses can’t be easily coupled. Anybody with math: any improvement? Driver training time worth whatever it costs. That’s how transit handles obstacles. Removing them?

      That’s what passenger political participation, elections, and recalls are for. Good luck, David. You can handle it.


    2. It isn’t necessary but the convention center doesn’t reallly care about the disruption it will cause so it is what they are doing.

    3. @David,

      The switchover to the new SR 99 tunnel will actually be complete a full month before the buses are kicked out of the DSTT.

      The new arterial on the waterfront, not so much.

      1. Yes, I know the switchover is _scheduled_ to be complete before buses come out of the DSTT. However, I believe that none of the buses currently in the DSTT will be realigned onto the SR 99 since they obviously have to stop in downtown. So, those buses will be put onto surface streets. Info is really hard to find, but my guess is that most (all?) of the DSTT buses will be realigned on Third Ave, which is already clogged BADLY. I took this video last night at 5:20pm at 3rd and Pike:

      2. The Times has a map of the viaduct reroutes. The buses are already on 3rd north of Columbia so nothing changes there. South of Columbia for three weeks they’ll be southound on Ave, 4th S, Martinez, 1st S. Northbound SODO busway, 4th S, 3rd. Then for 9-12 months they’ll be both ways on 1st, Dearborn, 99.

        None of Metro’s routes are expected to use the 99 tunnel until the 2040 plan, when a West Seattle express is planned for Fauntleroy – WSJ – SLU. None of the downtown routes will use it, and I haven’t heard of any other routes from the south end to SLU.

      1. the STB piece seems to describe just the connection with the D-2: “Patrick said that “there’s no way to finish construction” without the single-tracking, which will be located just south of the Chinatown/International District station. Switches will be installed in the tunnel guideway, to connect East Link’s ramp—which previously carried Eastside-bound buses into the DSTT—to the existing rail network.”

  6. ST will run trains in both directions on a single track

    OMG, ST is starting to act like a real RR! Now, if only they’d adopt solutions the rest of the world has used for centuries we might actually get rail service to places that would use it for something approaching affordable. Credit Rogoff for one thing done right.

    1. ST already uses single-track operations during maintenance. The rest of the world does not use it for regular corridors that have Link’s volume because it halves the potential frequency. It’s only used for low-volume coverage branches, spurs into train stations (although I’ve only seen those on mainline trains), and perhaps century-old lines.

      1. Chicago has single tracked red line operations many times over the years of their capital construction projects. And more is on the way on the far north embankment upgrade projects. The red line north side ridership is higher than Link.

        The magic trick to single track is length and reliability of switches/speed in the single track section. The CTA kept the single track operations down to a couple stations (and improved the tracks switches to keep the speed up before they single tracked) and it definitely was noticeable, but not that bad.

    1. (All I see online is a couple mentions from Siemens that the trains will begin testing in 2019)

    2. According to the October progress report, the first Siemens car is already in testing, while the second is in final assembly. The first car is scheduled to be delivered to ST for testing in the 1st quarter (before March) of 2019, while final acceptance is estimated at October 2019 (which is a likely service date).

      1. I’m not sure from the report when the first Siemens LRVs are scheduled to go into revenue service.

        By my math, we’ll be stuck with 3-4 2-car Kinkysharyo trains in the peak loop until then, unless Ops has a trick up its sleeve to remove one more train from the loop. Having all three-car trains would reduce and standardize dwell time, and further improve reliability.

      2. This is unfortunate. I’m usually on the morning commute heading north and the buses in the tunnel add some capacity, particularly for sounder commuters who just need to head north in the tunnel and don’t care if it’s a train or bus.

        With the train car fleet at capacity and no more buses in the tunnel, the trains are going to have to do some more work until the new trains come online.

  7. This is really good news — about fricking time the DSTT went to rail only! This will significantly improve Link reliability while also reducing transit time through the CBD. A major improvement for Link.

    Single tracking while they connect East Link is unavoidable, but should be of a pretty short duration. And it appears that ST is scheduling this for after the new rolling stock begins to come on-line, and before NG Link opens, so the disruption should be nil to none.

    Joint Ops was an abomination. Good riddance, just wish it was sooner.

    1. More than nil. ST has single-tracked in Rainier Valley evenings during some maintenance periods, and the frequency goes down from 10-15 minutes to 20 minutes.

      1. They will schedule this for a period where ridership is expected to be low. And they will compensate for increased headways by going from 3 to 4 LRV trains where possible. Plus the changeover shouldn’t take that long. It will be quick.

        This is hardly going to be an issue.

  8. Yeah, 2020 is the best time for this. Pre-Northgate passenger loads + when the tunnel is rail-only. Hopefully they do it early in 2020 when seasonal and sports-related ridership is lowest too.

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