Last week Zach reported on the 7-day WSDOT construction project that will reduce Westbound I-90 to as little as one lane. The potential for epic backups, engulfing both transit and drivers, is obvious. I asked WSDOT Spokesman Travis Phelps and Traffic Engineer Mark Bandy what the exact implications were for transit, and what more could have been done.
The first half of the closure, Stage 1 depicted above, is “probably more impactful” than Stage 2, and it’s no accident that the bulk of this work will occur over the weekend. With the HOV lanes entirely closed, buses will merge into general traffic, thus discouraging their use at the point of maximum need for spatial efficiency. I asked Mr. Bandy if WSDOT would consider making one of the remaining lanes HOV, setting aside for the moment that the planned configuration withers to one lane for a short stretch.
He said in any project “we would assess if it made sense to make one of the lanes HOV,” but the agency’s experience was that to create compliance WSDOT would “have to paint it and put the markings down,” rather than use a sign or other simple measure. The restriping operation itself would be a matter of days, in support of a closure that will only amount to 3 or 4 days. “If we were talking about this configuration in place for 3 months we’d be having a different conversation,” Bandy said.
So Stage 1 will be a disaster; Stage 2 may be mildly better for transit. As a transit user, if you can possibly delay your trip to the later part of the week, that would be wise. The bad news is that I-90 buses will have to share the HOV lane with all mainline traffic when it withers down to one lane. It would be theoretically possible to instead divert all SOV traffic into the collector/distributor lanes and leave the HOV lane clear, but Mr. Phelps dismissed that as “difficult.” If there’s a saving grace for the 554 et al it’s that they’ll occupy the continuous lane and therefore have an advantage over merging traffic.
For the 550, however, Stage 2 will be much better. Although it’ll have to share the Bellevue Way onramp with SOVs, Stage 2 injects it into the I-90 mainline after the merge, which will act as a meter.
Under normal conditions, buses in the afternoon peak ride in the HOV lane until it ends on the eastern shore of Mercer Island. There is usually some backup in that merge, and as buses cross across four stop-and-go lanes to serve the Park and Ride. Buses experience further delay getting back on I-90 from the stop. (In the morning peak, HOV lanes lead right into the express lanes and their own ramp to the P&R.)
With traffic on Mercer Island likely to be free-flowing, all of this delay is likely to improve. It would be dangerous to conclude that 550 flow will be better than normal in Stage 2, but there are countervailing forces that make it less than a total disaster.
The impacts will be different in each stage, and will differ for Bellevue Way and I-90 buses. And of course the scale of delays will largely depend on the ability of people to adjust. Fortunately, tolls will remain on 520 to prevent that bridge from grinding to a halt. But the advice for transit users is straightforward: delay your trips to the second half of the week or beyond, switch to 520 buses, or use a bike.