Near-term Options for Montlake Transit Mobility

Cars queued up at the Montlake offramp

When the new 520 bridge opened last year, it created a glorious, continuous HOV-3 lane from Bellevue all the way to Montlake. Unfortunately, it also created a new bottleneck for buses: the Eastbound offramp from SR-520 to Montlake Blvd has become a notorious parking lot for cars and buses exiting the freeway, as any passenger on the 255 or 54x buses an attest.

When WSDOT finishes the Montlake lid in 4-5 years, things will get better: buses will have a dedicated exit from the left-hand HOV lane onto the surface, potentially all the way to and from UW Station.

Future transit-only Montlake offramp (WSDOT rendering)

Alas 2023 is still a ways away, so STB reader Glen Buhlmann invited STB and some fellow transit advocates to meet with WSDOT staff at the Montlake offramp to see if there were any opportunities for near-term improvements. As bad as the situation is now, even more buses may need to be truncated at UW in the near term.

In the current configuration, the Montlake exit consists of two general purpose (GP) lanes. Today, buses spend 10-15 minutes idling in those lanes during the afternoon peak. There's a wide shoulder for some of the offramp, but not the whole thing, so building a dedicated bus lane isn't a realistic near-term option. It would take significant planning and construction during a time when whole area will already be a giant active construction site. Maintaining two exit lanes throughout lid construction will be a herculean task as it is.

If bus throughput is to be improved, therefore, it'll have to be within the existing right-of-way. Could one lane be repurposed as a bus lane? WSDOT says that such a move would cause too many cars to back up into the main highway. While this isn't a big deal at rush hour (no one's moving very fast anyway), it would present a safety issue at mid-day, when traffic is flowing at 50 mph across the bridge and slams into GP exit ramp traffic spilling on to the main line. (this apparently happens often when the Montlake drawbridge goes up).

(Cars used to have a free right turn onto Montlake Boulevard, which may have allowed more throughput, but at the cost of pedestrian safety. So SDOT would prefer to avoid that arrangement as well.)

One promising idea that came out of the group brainstorm was to convert one of the two lanes HOV-2 or HOV-3 at peak only. That could be done relatively quickly, and would allow buses to move a bit faster through the offramp (perhaps saving 1 light cycle) while preventing the mid-day backups that present the biggest safety concerns. You'd have the usual enforcement issues, but it still might be better than today. WSDOT promised to investigate.

Checking out the offramp and the surrounding environment. From Left: David Goldberg, community liaison for SR-520, W.D. Baldwin, engineer, Laura Goodfellow, Brock Howell, and Glen Buhlmann

In the meantime, buses will continue to sit on the offramp for want of a dedicated lane, despite the fact that our regional leaders are nominally in agreement that we urgently need to improve the transit experience during the "period of maximum constraint": Seattle is spending a good deal of money to improve the bus transfer at UW station, Eastside communities seem to want a more reliable commute for their constituents, King County Metro could really use the service hours it's wasting on congested buses, and WSDOT would like very much to have fewer vehicles driving through an active construction site. Everyone seems to want transit priority, and yet the status quo prevails. If the situation is to be improved in the near-term, political pressure will have to be applied at all levels - the city, the state, and the county - to change that.

Talking about moving people rather than storing barely-moving cars. Thanks @transitrunner @BrockRides @jdubrule @fchi for joining in the conversation. Props to @fchi for the pic. pic.twitter.com/PDhR58sjvt

- Glen Buhlmann (@GlenBikes) June 20, 2018