State transportation planners spent lots of time this week explaining long-term plans for fixing 520 between Seattle and the Eastside.

But what about easing the commute now?

At an open house at Bellevue High School Tuesday night, there were detailed displays about plans for a new six-lane bridge, including features like bike lanes and steps to treat runoff water and use new quieter cement. Assuming passage of the transportation tax package this fall, the new bridge would be open for traffic … in 2018.

That distant date explains why commuters are so unenthused. Why give up a sunny evening to discuss a project that seems like it will never happen? No one can say planners haven’t been inclusive, with open houses and hearings ad nauseum. (On Tuesday DOT staff sometimes outnumbered the public.) What’s missing is anything to help now or build enthusiasm for change.

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.

As it stands, taking the bus usually isn’t an appealing option and there’s plenty of opposition to the 520 replacement project. One protester at the Bellevue event this week handed out flyers urging a vote against this fall’s tax plan because he wants politicians to craft a better one someday. Instead of risking that kind of delay — and keeping us all stuck for years — transportation leaders should make relatively small changes necessary to improve movement now.