SR 520 bus service when the bridge is closed

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.