I wasn’t actually at this stop, and can’t confirm whether this was the actual situation on the ground or OneBusAway weirdness. But for a 15-minute headway bus on a Saturday afternoon, yikes. [Update: Numerous commenters say they witnessed this.]

43 Replies to “Extreme Bus Bunching”

    1. I’ve seen maybe two 150s get bunched but don’t they sort them out at “timed transfer points” like Tukwila?

      (And the 150s seem to be dethugging…thanks, KPD!)

      1. There are no timed transfer points. but as it is 150 #1 was running behind. Maybe make more sense to empty those passengers getting off before the freeway and continue straight to downtown?

  2. I think they do AVERAGE 15 minute headways, which has little to do with when the bus comes.
    Remember: “A bus at the stop is worth two on the schedule”.

  3. The operational answer to bus bunching is to allow buses to leap frog each other. I understand it is current Metro policy that that is prohibited.

    1. I rode an 8 on Denny today that was part of a gaggle of three, so I can confirm OBA was telling the truth here. Metro policy permits leapfrogging but it did no good in this case because both lanes of Denny were gridlocked.

      Denny is fundamentally broken as a transit street, and there’s not much that can be done in the short run about it.

      3. Agreed, and I think we should break lines and coupled routes where a persistently problematic corridor is likely to cause system delays. So, I think RapidRide route D may encounter problems in the Denny/QA/Interbay corridor and RR-C may encounter problems in the SR99S West Seattle Freeway corridor. Problems in either one create delays in both.

        Problems on route 8 along Denny create delays all the way downstream on its route.

      4. How about just truncate the 8 in capitol hill and ask people headed to south lake union to go downtown and take the slut?

        Given that almost everywhere the 8 goes already offers a one seat ride to downtown on some sort of bus (I’m assuming here than no one in their right mind would ride the 8 all the way from MLK & Graham St. to South Lake Union – that seems utter torture), this can’t be any worse than the gridlock we have on the 8 today.

        In return for this, we get drastically more reliable service on the rest of the #8 line, plus we save service hours that could be used to make either the slut or the remaining portion of the 8 more frequent.

      6. We need more crosstowns, not fewer. Our network is already too downtown-centric.

        Today the Mercer ramps to I-5 were closed, so Denny pulled double-duty as an I-5 queue. There are some things we could do to Denny for modest gains, but really Denny is a strong candidate for grade separation.

      7. In Metro geologic time, the 8 is a relatively new route. It was started because it took absolutely forever to get from LQA to Cap Hill, because you had to transfer downtown and both legs of that transfer were excruciatingly slow.

        Most times of day, it works. But in the mid- to late afternoon on weekdays or Saturday…

        For now, I think the solution is just to split the 8, restore reliability to the south half, give as long layovers as reasonably possible to the north half, and let it suffer. Other solutions will cost huge amounts of money.

      8. I 2016, how long will Capitol Hill->Lower Queen Anne take via Link->Monorail or Link->1/2/4/D (whatever comes first)? I’m guessing the 2-seat ride would actually be faster than the one-seat ride on the 8 today.

        Ultimately, though, I think the real solution is Matt’s gondola idea.

      9. People clamored for decades for a Queen Anne-Capitol Hill route. It was the most-requested route and finally it happened, and then the hours and frequency were expanded again and again because it was so popular. My neighbor who lived in Summit in the 1950s (and still does) walked to Queen Anne High School because it was faster than going downtown and transferring.

      10. The solution is to remove the Denny freeway ramps, end of story. A fundamental truth of freeway interchanges is that they should not be located on roads that also function as city arterials for non-freeway traffic. Mercer is fine, because it ends at the freeway. Even if it gets backed up, at least it is mostly just affecting freeway-bound traffic. On Denny, the people queueing up to get on the freeway are imposing a negative externality on all the through traffic, including buses trying to stay on a schedule. Besides removing the ramps, they could also be moved to side streets so that the queue doesn’t back up onto Denny.

      11. My alternative routing for the 8 that will be possible once the viaduct replacement/DBT project is complete, and avoids the worst of the rush-hour gridlock:

        Starting westbound on Denny as per current routing
        Northeast on Broad (upgraded signal or zig-zag via 4th)
        West on Harrison (over new SR-99 crossing – part of viaduct replacement project)
        South on Fairview (crossing Denny)
        Southwest on Boren
        Northwest on Olive.
        rejoin current routing at Olive & Denny.

        This gets the 8 off of Denny and (mostly) out of freeway traffic, while still keeping it in the same general area. It would also better serve SLU as an E/W route on Harrison (or Thomas, or really any of those SLU e/w streets – I just picked Harrison because it’s signalized at every major intersection) than on Denny.

        All the zig-zagging would slow it down in the off-peak, but avoiding the freeway queues and associated backups would make it more reliable overall, I think.

        And I endorse Bruce’s latest 8 splitting plan.

      12. “I 2016, how long will Capitol Hill->Lower Queen Anne take via Link->Monorail or Link->1/2/4/D”

        The main issue is that people aren’t just going from the monorail station to Broadway. They’re going from Queen Anne Avenue to Summit, Whole Foods, 24 Hour Fitness (Stewart St), 15th, or any of these pairs. Many people take the 8 a short distance simply to avoid climbing hills. As to how much Link will impact Queen Anne – Broadway trips, I don’t really know. It may give a greater incentive to take the monorail, now that there’s rapid transit on both sides of the transfer. Right now the only people who take the monorail are tourists or those who are willing to pay extra (no transfers accepted). Maybe as Monorail+Link becomes dramatically better than Monorail+bus, more people will take it.

      13. Ironically, when I lived on Summit north of Olive, I rarely took the SLUT because it was perpendicular to most of my trips. I would have taken a Denny Way streetcar if it existed. Now I live near Summit & Pine, so it’s shorter to transfer at Westlake than it was, and I normally do that.

    2. “I understand it is current Metro policy that that is prohibited”

      I didn’t think it was prohibited and have done it many times but after reading the September 2012 “Book”, I’m not so sure. (I’ll consult training on Monday) Either way, Bruce’s comment below gets to the crux of the matter: Denny is broken as a transit corridor.

      (Policy does allow us to pass a stop if we are in the lead and we can see our follower – that’s why I always encourage people to take the 2nd (or 3rd) bus)

    3. I have seen 550s do this, at Mercer Island, S Bellevue P&R and all along Bellevue Way. have also see B line buses do this as well

  4. Yep, I can confirm this was reality. I was hanging out at Miller Playfield (19th and Thomas) and saw at least three 8s together. Personally, I think they should have done some sort of maneuver such as sending one downtown like a 43 and then up 3rd to Seattle Center or something.

    1. The 43 route between Denny and downtown is so slow, particularly on a Saturday with massive shopping crowds along Pine Street, that I don’t think that would help much.

  5. Driving down I-5 today, I noticed the Mercer Street exit ramps were closed, so this is definitely believable.

  6. Explanation at http://en.wikipedia.org/wiki/Bus_bunching

    For deep diving transit geeks, there is a simulation you can play with at http://turing.iimas.unam.mx/~cgg/NetLogo/metro.html.

    I’ve seen bunching of trains on the crowded systems of MetroRail in Washington, DC and in the Mexico City subway. For what it’s worth, I’ve never seen train bunching on the centrally monitored automated rail transit system in Vancouver, BC during several experiences riding it in crowded conditions.

    1. Bunching on the 8 in most cases (this being one of them) has little to do with the phenomena described on that page and everything to do with Denny being so hopeless that buses end up arriving ridiculously late to their layover, and then setting off from the terminus at about the same time. It thus cannot be cured using bus bulbs, bus lanes or any other cheap technique to improve reliability.

      1. Could we have buses intentionally wait at the terminal past their scheduled departure time if another identical bus just left a few minutes before? Essentially switch from a rigid schedule to a headway management system.

      2. Metro’s new onboard system supports automatic headway management, but it’s currently disabled. A large-scale rollout on the frequent transit network would be years away; I suspect we’ll see it trialled on RapidRide before then (although I know of no official process in the works even for that).

        Less ambitiously, yes, it’s absolutely possible that more accurate GPS data from the new OBS would allow supervisors to split up badly-platooned buses by ordering one (or more) of them to transfer their passengers to another and pause in a zone or switch back, or just go back to base. This would work great on routes like the 36 which, in the outbound direction, have several switchback opportunities, and are often lightly loaded in the place where platooning is most egregious, but it still wouldn’t do much for the 8, as Denny and the surrounding area is frequently so bad that no bus can get ahead or turn back, in service or not.

  7. In the University District, I’ve seen 4 43s at once (2 one way, 2 the other) and 5 48s at once (3 one way, 2 the other). If the 48 is electrified, they need to have sufficient passing wire.

    1. Or off-wire ability. The new trolleybuses, if they’ve specified the bid requirements, correctly, should be able to run offwire for short distances. For instance, across an intersection (to avoid special work), or to pass.

  8. I saw the massive backup on Denny yesterday at around 6 PM. Since I was walking all the way from Eastlake to Mercer, I can tell you that most of the cars were in line to get on the onramp to southbound I-5 at Yale street, since the Mercer street onramps and the 520 bridge are closed. I did walk by three bunched-up eastbound route 8’s, noticing that one 8 was four cars behind another 8.

    This is what a coordinator is for. Even if you can’t get the buses on the correct schedule, at least make some attempt at restoring 15 minute headway.

    1. SDOT and WSDOT need to work together to fix the problems caused by people queuing for the Yale street on-ramp. I’ve seen suggestions on how to fix it and on how to keep drivers queuing from blocking the box on Stewart or Howell and from clogging up Denny.

      Perhaps the solution is to close all of the ramps between James and Mercer and only allow transit and carpools.

  9. Last time I tried to take the 8 I waited for over a half hour, then walked 8 blocks (still no sign of the 8), then took a taxi. If it’s this broken yet still popular, inagine the ridership if it were fast and dependable.

    1. My early afternoon Saturday ride on an 8 from E John & 15th Ave E to Uptown, was packed most of the way. The Aurora intersection was the part of Denny that slowed us down to a crawl.

  10. Most people say that they hate saying I told you so, but I love saying it.

    From a Service Change Post on STB on January 12, 2009, one of my comments:

    ” … sending the 8 down to Henderson Street doesn’t make sense to me. It originates on lower Queen Anne and travels down the congested Denny Way. It seems to me it’s going to cause it to have frequent scheduling issues.”

    1. That argues for splitting the 8, not eliminating the Denny Way segment. As I said above, people very much want a Queen Anne – Capitol Hill bus even if it gets caught in Denny Way traffic. Because that’s still better than walking up several hills or going downtown and transferring.

  11. I have seen this bus build up in action on the Lower Queen Anne side. When the Driver gets behind on the scheduled instead of floating at the end stop (no passengers) to reset scheduled the drivers push on often missing a lunch or a needed break. I am hoping when all the buses have GPS that central will hold buses to get back on schedule. There has to be a time loss ratio for this. Catch up is often not a reality especially on this route. I often find metro management lacking basic route problem solving skills. Here is a free class “An Introduction to Operations Management” from University of Pennsylvania.
    https://www.coursera.org/course/operations

  12. as Bruce stated, Denny Way is quite congested and difficult for transit operations. even when traffic is normal (and normality has a broad range), it is congested. in the morning, there is congestion at the Aurora Avenue North exit; in the afternoon, the southbound ramp to I-5 near Yale backs up; Seattle Center events cause gridlock. Today, there is also Mercer east and its closure of Fairview Avenue North. A few years ago, SDOT had a good description of the traffic choke points where the street grid shifts; Denny Way is one. Westlake Avenue North, south of Lake Union was recently an empty street; now, it has vibrant activity and a streetcar to which SDOT has provided some signal priority, at the expense of green time for other movements. One minor improvement: ban left turns at Terry Avenue; they add unnecessary friction. Route 8 has three largely unrelated segments.

  13. The Denny traffic was exacerbated by a disabled vehicle in the right lane at the crest of the hill just west of Fairview.

  14. I am Jack’s complete lack of surprise. This happens a lot at 2nd & Jackson too. And the tunnel routes? Go ahead go visit a tunnel station for 15 minutes and count the sheer number of identically-numbered buses go through. Any time of day. The 150 and the 42 are prolific offenders.

    1. You’re a little behind the times. The 42 came out of the tunnel five years ago.

      But yes, the tunnel is bad in the peaks. Midday, it’s fine, and several minutes faster than an equivalent surface trip.

  16. The 358’s running during evening rush hour often leap frog over each other. There is definitely a lot of bunching that happens on that route. But the service is so frequent during evening rush, even with bunching, you tend not to have to wait long for a bus. You do end up with one bus being crazy crowded and the one two minutes after it being empty, though, since most riders are getting on south of the bridge and most riders are getting off north of the bridge. It’s rare for there not to be at least one person getting off at every stop north of the bridge, so the crowded bus tends to move sloooooowly and the empty bus sails on past. Moral: use OBA to see if that crowded 358 is being followed closely behind by an empty one, because you’ll probably get home faster on the empty bus.

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