Rendering of the future Montlake lid over SR 520 (image: WSDOT)

This weekend, there is a full closure of the SR 520 bridge over Lake Washington. Closures of the bridge in at least one direction is going to be a somewhat common occurrence for the next few years as WSDOT works on their Montlake lid project, which will ultimately improve bus service from the eastside to UW, and get buses out of the general purpose westbound off-ramp that often gets backed up with traffic.

All buses that use the bridge are going to be rerouted from Friday, March 5th at 11:00 p.m. through Monday, March 8th at 5:00 a.m. Routes that are affected include Sound Transit routes 542 and 545, and King County Metro routes 255 and 271. Stops that are missed include the Evergreen Point and Yarrow Point freeway stations, and local stops in Medina that are west of 100th Ave NE. Aside from those missed stops, the reroutes are configured to serve the same stops in the same order that it would normally, just with some significant delay due to the fact that buses have to divert to I-90.

While this configuration is optimal for reducing confusion and making sure service operates as normally as possible, it does lead to some highly inefficient operation for routes that go to the U-District. Routes 255, 271, and 542 westbound detour south to I-90, travel west toward downtown Seattle, but continue back north without stopping in downtown, and take SR 520 eastbound, then continues as normal on Montlake Blvd E. This is particularly awkward for route 255, as last year its southern terminus shifted form downtown to the U-district to expand service. However, when the bridge is closed, the situation is completely different in a couple of ways.

  1. It is no longer faster to send the bus to UW than to downtown, since it has to pass right by downtown anyway, and UW is out of the way.
  2. Downtown riders who continue using route 255 by making a transfer to Link have an even worse trip. Not only is the trip longer by having to detour to I-90, but then they are taken past downtown up to UW, and then have to transfer to Link to get back toward downtown.

The sensible solution here seems to be to just send route 255 to downtown again, instead of to the U-district. Metro could send route 255 to 5th Ave like the old 255 (but in the reverse direction, of course), or they could just end it at the International District/Chinatown Link station, and utilize the same layover space that route 106 uses (which would save even more service hours). In any case, trips to downtown would get more convenient, and trips to UW would require a transfer to Link.

For the passengers using route 255 to reach downtown Seattle, the current detour routing that skips downtown is a lose-lose: rather than being able to get off at downtown after exiting I-90, riders have to go up to UW and back, with a transfer to Link at 15 minute headways. And Metro loses because it has to have more coaches in circulation to keep service up to UW. As stated before, normal usage of the stops that it can serve is an advantage, but it’s the only advantage. And with the ways available to get the word out via online alerts, text message, operator announcements, and flyers on board the bus, communicating changes is much less of a challenge than it would have been in the past.

Another way to reduce confusion is to alter the name of the route, for example, by calling it something like “255B” (for bridge), and referencing route “255B” in rider alerts online and at bus stops. This way, the detour planning can also be done on a more permanent basis. A similar thing is actually done for snow routes (something that is likely to be much less frequent of an occurrence than construction-related bridge closures), where parts of many routes are broken off into a separate snow shuttle version of that route.

A similar change could also be done for route 271, though transfers in this case would be more inconvenient than form route 255 due to the fact that route 271 operates every 30 minutes at best on weekends, and 271 ridership is less likely to be heading downtown.

For route 542, it may make sense to send it downtown and follow the same routing as route 545. This would make it the same as route 545 except it doesn’t run east of Redmond TC. This would allow Sound Transit to double the frequency of Redmond-downtown Seattle service from every 30 minutes to every 15 minutes, which would help mitigate the added inconvenience to U-district-bound passengers.

14 Replies to “SR 520 bus service when the bridge is closed”

  1. There are no busses on that image. What lane(s) are they supposed to be on?

    1. The pretty clearly marked HOV lanes right down the center of the picture? WSDOT’s illustration software only had car models, no buses apparently.

  2. I understand the out-of-direction frustration.

    Does the reroute pull off the freeway somewhere? If so, where? Mercer Island seems the easiest and the least time-consuming . A quick jog through Downtown seems reasonable too but that’s sure to add a bit of time.

    Regardless, I think that it still needs to end at UW Station. A route is generally expected to hit all major points and even closing a minor stop needs obvious noticing.

    It’s too bad that there isn’t a small ferry boat with docks so that a bus could simply drive on and off of it. Having one seems like a possibly strategic investment — even if it isn’t put into daily service. Since Lake Washington doesn’t really change its water level, a dock installation seems pretty straightforward.

  3. I think this makes sense. So far as I know, all of the closures are on the weekend. I would send the 255 to downtown on the weekends (every time), and keep the regular routing the rest of the time. Ideally you change the route number, but even if you didn’t, riders would figure it out. On weekends, the buses go downtown, on weekdays they go to the UW. Pretty simple. I would run the buses through downtown the same way every time. Consistency.

    With the 271 I would probably just truncate it at Bellevue TC on the weekends. Either that, or make it an express from downtown Bellevue to the UW every time. It doesn’t make sense to duplicate the 550, and run to downtown Seattle. The main thing is, like the 255, the bus route is consistent. Every single weekend it serves the same stops in the same order.

    Likewise, I would probably just suspend the 542 on the weekends, and run the 545 a bit more often.

    In many cases this would be worse for riders, but cutbacks have happened all over. With the 520 shutdown, these routes are no longer an especially good value on the weekends (if they ever were) and it doesn’t make sense to spend a lot of money trying to pretend the bridge is still open.

    1. I don’t like it. Bridge closure weekends are still a small proportion of all weekends. If the 255 went downtown, all those extra service hours traversing downtown would reduce frequency. This means goodbye 15-20 minute service, and a return to 30 minute service (or, maybe 60 minute service in the evenings).

      It also adds out of direction travel to not just the UW, but really all of Seattle north of the ship canal. There’s a lot of trips where it is much quicker to take the new 255 to a U district bus than to take the old 255 to a downtown bus. Green Lake, Greenwood, Wedgwood, Lake City are just a few examples that come to mind.

      At least with the current routing, you can simply delay discretionary trips to another weekend when the bridge is open. Under your proposal, it’s either go during the week (which means, taking time off work), spend an extra half hour or so each way, or go buy a car. It’s an overkill reaction to a few isolated bridge closures and it’s not necessary.

      1. How isolated is it though? It seems like it is happening every weekend (one direction or another). When it does so it costs money — it doesn’t save anything. I can also assume that ridership has plummeted when you aren’t even sure where your bus is going.

        Its not like you can’t get to the UW. You can always go downtown and take Link (just as folks are going to the UW and taking Link to go downtown in the middle of the day).

      2. I think the “normal” during the construction project is maybe once every couple of months on average. We just happen to be in a short term phase of the construction where it’s happening more often. Once they finish getting the girders placed for the Montlake Lid, that will change. It was similar when they built the lids on the other side of the lake a few years ago.

        “Its not like you can’t get to the UW. You can always go downtown and take Link (just as folks are going to the UW and taking Link to go downtown in the middle of the day).”

        Yes you can. But, that’s about 8 miles of back and forth. Plus, there’s no downtown Link station right at I-5, so you have to sit through all the downtown stoplights on the bus to get to Westlake station to go north, on top of waiting for the train, going up and down the escalators the same. Add it up, a detour downtown on the way to UW adds a lot more time than a detour to UW station on the way downtown.

        I do think it’s entirely reasonable for the rerouted 255 to serve Mercer Island (assuming the island doesn’t sue to stop it), but I wouldn’t do something so drastic as to shut down all Eastside->u district service on every weekend, just because the 520 bridge is closed on some weekends.

      3. We just happen to be in a short term phase of the construction where it’s happening more often.

        Then this is when the buses should go downtown. If this was a once in a blue moon event (like the snow schedule) there wouldn’t be this article. This is happening quite a bit. I think we need a better assessment as to how many times the 520 bridge is going to be closed — something lacking in this essay. But it sure seems like the bridge is closed a lot. If that is going to change in a few months, then it is pretty easy to just go back to the old schedule. If there is a “period of frequent closure” (which is what I believe we are in) then we should restructure the buses during that period.

        Every time it is closed it costs Metro a huge amount of money. For a bus from the UW, you have to allot for the extra time to go around, as well as the extra time in case the Montlake bridge is up (which will go way up on the weekends this month). The main reason the 255 goes to the UW was to save money — they aren’t saving it right now. An express to downtown would likely save more riders more time. As much as the UW is a big destination, downtown is bigger.

        Stopping off at Mercer Island would be nice, but just delays the bus further, and adds to the confusion. Will the bus be stopping there on the way back? Maybe, but what if 520 is closed one way and not the other? That would mean sending the bus all the way around again to serve riders who assume that if the bus stops on Mercer Island one way, it will stop the other way.

        The point is, we can keep the status quo, but it is a mess. You can send the buses to downtown (or Mercer Island) some times, and not others, but that is even messier (you have to check the website to even know where to wait for the bus). On the other hand, making a weekend change (for the period when these sorts of closures are common) seems like the best mix. It means a period where weekend service does something different than weekday service, which is quite reasonable.

      4. Add it up, a detour downtown on the way to UW adds a lot more time than a detour to UW station on the way downtown.

        I disagree. It is about the same. The 212 for example, goes through just about as many lights to get to the I. D. station as the 255 does to get to the UW station. Likewise, the 41 uses Union, which then gets over to Third very fast, which connects well with the University Station. In both cases it is way more consistent then going to Montlake, where the bus might be held up by a bridge opening. Eventually this won’t be an issue. Eventually a bus will be able to get right to the front of the line when the bridge is up, and just wait for it to go down. But now, the bus may be waiting on 520 for the bridge to go down, and then wait as traffic slowly filters out.

        The bridge opening is bad for the rider, but terrible for the system. When it comes to costs, consistency is very important. If a bus is periodically 10 minutes late it means that every bus is essentially ten minutes late (from a cost standpoint). You just build in the extra time, assuming the worst. I’m not sure how the bridge closing is handled, but it has to be similarly expensive. My point is that on weekends, I don’t think Metro is saving anything by sending the bus to the UW versus downtown.

        Meanwhile, my guess is, most riders would prefer going to downtown, probably by a wide margin. There were really two reasons why they sent the bus to 255:

        1) Save money.
        2) Deal with the loss of the Montlake 520 stop.

        In the second case, it wasn’t just for Kirkland (one-seat) riders. It was also because the 255 stops at the 520 freeway stops. This means that riders from buses like the 252, 257 and 311 could transfer to get to the UW. It would have made more sense to reroute the 271 onto Bellevue Way, but for whatever reason, Metro didn’t want to. So the 255 did the work. Here is the thing though — almost all those buses don’t run on the weekends. The one exception is the 545. But only a handful of riders (if any) actually did that. Forty riders a day would get off at the freeway station headed downtown. My guess is all of those were on the weekday (including folks who used the park and ride to get to Redmond).

        There is just a very weak case to send the 255 to the UW *on weekends*. The case is made even weaker with the lack of reliability currently in the system.

      5. Let’s start with the westbound direction, starting from west end of 520 bridge:
        – to downtown via UW:
        2 minutes (drive down ramp and wait for light)
        1-2 minutes (drive down Montlake to bus stop
        2 minutes (take escalators to platform)*
        0-10 minutes (wait for train)
        6 minutes (ride train)
        2 minutes (take escalators to surface)
        Total: 13-24 minutes
        – to UW via downtown:
        5 minutes (drive down 520/I-5) (**)
        5 minutes (drive down Stewart to 5th/Pine) (***)
        2 minutes (walk down escalators to platform) (*)
        0-10 minutes (wait for train)
        6 minutes (ride train)
        2 minutes (walk up escalators to surface)
        Total: 23-33 minutes

        Now, let’s do some subtraction to figure what the penalty is for each trip over the direct route

        to downtown via UW:
        detour route: 13-24 minutes
        direct route: 10 minutes
        penalty: 3-14 minutes

        to UW via downtown:
        detour route: 23-33 minutes
        direct route: 2 minutes
        penalty: 21-31 minutes

        As you can see, the penalty of going to UW via downtown is far more than the penalty of going downtown via UW. It’s not even close. Averaging the two ranges, you would need 5X the passenger volume going downtown vs. UW for the total person-minute delays from the detour to equalize. Downtown may be more, but it’s not 5X more. Especially not during COVID when downtown events are shuttered and the destinations of transit riders that remain more likely to be scattered throughout the city than concentrated in one place.

        Yes, you could have the bus take Union instead of Stewart, but it doesn’t really help. You save a couple of stoplights, you sit on the train for an extra stop. 6 of 1, half dozen of the other.

        (*) Assuming that the rider already has an Orca card and can skip the ticket machines
        (**) This is a best guess, as Google refuses to generate a time estimate for when the bridge is open on a weekend when the bridge is closed
        (***) This assumes the bus skips all stops on Stewart St; if it doesn’t, it will be longer; the lights are timed so that nearly every bus stop causes the bus to miss the next light.

  4. According to WSDOT, 84 girders over the Montlake lid have been set, as of Thursday, with 30 to go. I don’t know if this weekend’s closure is doing all 30 or just some of them, but the point is, the phase of semi-regular bridge closures is nearing the end and, before Metro’s bureaucracy could even approve a route change like you suggest, it would already be obsolete.

  5. I wonder wgat will happen for east link wgen i90 closes for maintenance. Will ST have a bus go from South Bellevue to UW station via 520?

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