State moves step closer to 3-person carpool lanes on I-405

SEATTLE -- Get ready for big changes to Interstate 405.

On Wednesday, the state moved one step closer to adding tolled express lanes to the corridor, where carpools will require three people in the vehicle, not just two. That new carpool requirement would be a big change from what is the norm in the region.

Transportation leaders say the major problem right now with the current HOV lanes on I-405 and elsewhere is that they are too popular.

“Two-plus carpools have become so successful and so widespread that they are really literally clogging the HOV lanes today,” said Kim Henry, the Washington State Department of Transportation's project director for I-405.

And that’s why the new express lanes on I-405, when they open in 2015, will be the first sizable stretch of roadway to raise the bar to three-person carpools to get the lanes moving faster.   Otherwise, if you want to use them, you’ll have to pay a toll.

“If you need to get somewhere and you need the speed and reliability,” Kirkland Mayor Joan McBride said, “you can just merge over into that toll lane and you can get where you need to go.”

McBride is a member of the 405 Advisory Committee that made the recommendation to the State Transportation Commission.

The recommendation would still allow two-person carpools during non-peak times.

Here are the basics of the I-405 Express Lanes plan:

Get ready for more of the same. State leaders say creating express lanes and increasing the carpool size is a trend that will spread as the region grows.

“This is a very important first step,” said Henry, “making sure we understand how this is going to work, how it fits, but also then how does that transition to other parts of the region.”

The state says they will finalize toll amounts by the spring.