This post originally appeared on Orphan Road.

Cascadia Report offers a fix for getting traffic moving on SR520 now:

So here’s an idea: Immediately move 520’s westbound HOV lane to the left side from Redmond to Seattle. Instead of being stopped by merging traffic in the right-hand lane, buses and three-person carpools could speed through the corridor. Forcing cars with one passenger to merge from two lanes into one before crossing the bridge would be a dramatic incentive to take transit or carpool.

The change could be made almost overnight and would boost capacity. Demand for buses would soar and suddenly people would be willing to carpool, even if it meant sharing rides with (gasp!) strangers. If drivers really wanted more lanes they would be incented to support funding a new bridge.

It’s certainly an idea I’ve had myself from time to time, as I sat in traffic on the bus from Redmond to Seattle (I used to work out there). I can certainly sympathize with CR’s daunting tale of a nightmarish afternoon commute on the bus. So long as the Westbound traffic on 520 doesn’t back up past the 405 interchange, you’re usually okay. But if it does… ho boy, things can get gnarly pretty quick.

Unfortunately, CR’s idea to shift the HOV lane from the right-hand side to the left (thereby preventing buses from getting stuck in the 405 snarl) won’t work, from what I understand. It turns out that the HOV lane on 520 is an afterthought. It was a shoulder lane that WSDOT converted to an HOV lane after the fact. As such, it’s not safe enough for general-purpose traffic. (This is also why it has a 3-person HOV requirement.)

Here’s a 2002 report on the subject from WSDOT:

These shoulder HOV lanes can safely accommodate three-person HOV traffic flow, but not general traffic flow.

When the 6-lane bridge is eventually put in place, then it definitely makes sense to re-engineer 520 to allow general traffic in the right two lanes and HOV traffic in the far left lane. But that would require some major construction.

However, in the interest of being solutions-oriented, let me offer one of my own. The idea is simple: we could instantly reduce the traffic from Redmond to Seattle in the afternoon if we gave people an incentive to do a 2-person carpool. As it stands now, 2-person carpools get stuck in the general traffic along with solo drivers, so you might as well drive solo.

Since we don’t have the lanes to work with, we need other incentives. One option would be to pay people who do a 2-person car pool. How do you pay them? I’m not sure. Maybe they stop for some kind of coupon when they get to Montlake, or maybe we photograph all the cars and then send a check to everyone (by matching license plates) whom we can verify has a passenger.

The other option is good, old-fashioned public shame. Maybe make up bumper stickers or road signs that say “I’m doing my part to make this commute better… have you found a 2-person carpool?” I’m skeptical about such a solution, but since the majority of commuters coming back from the East side work for a few large employers, the community is tightly knit enough that social pressure just might work.

At the very least, we could make it easier for slugging to occur. I’ve been waiting at the bus stop on NE 148th in Bellevue several times and had a driver pull up and offer to take two people across the bridge to Montlake. Whether that reduces traffic or just makes for emptier buses crossing the bridge, I’m not sure.