Your ride on I-405 will cost you and your carpool may not save you

It’s more expensive to cross the 520 bridge this morning. A 2.5 percent increase in the tolls went into effect at midnight.

But tolls on 520 are just the start.

Your trip on I-405 is going to start costing you and having two people in your car might not be enough to get a free pass in the HOV lane.

The state is adding express toll lanes on I-405 between Bellevue and Lynnwood. That’s what all the construction has been about for the last few years. The tolls should be up and running next year.

The HOV lane will become a HOT lane. The “t” stands for toll.

Craig Stone, with the Washington State Department of Transportation, said the HOV lanes are too full to be doing any good, so it’s time to start charging drivers to use the lane.

“When we start thinking about those HOV lanes, they’re overused,” he said. “Even with two-plus people in the carpool, they’re breaking down.”

Drivers will have to buy their way into the new HOT lane. The toll will depend on how congested the road is. It will be variable, just like the HOT lane system on Highway 167.

“The key is keeping that lane free-flow, 40 to 50 miles an hour,” Stone said. “If people are stop and go, that’s not performing. We’ve really got to make these facilities perform.”

Stone said the data shows all the lanes improve when the HOT lanes are used. They’re saving drivers on 167 about eight minutes a trip right now.

“The general purpose lanes work better because there’s less pressure on them,” he said. “They see their speeds go up. They see the reliability going up. It really becomes more of a win-win for everybody.”

But for that to happen, the free ride in that HOT lane could cost you an extra person. Stone said the state transportation commission is considering whether to make the HOT requirement three or more people. So you will likely need three-plus for free use of the lane. Currently, two-plus gets you a free ride.

And to add another wrinkle, Stone said the state might make the HOT requirement variable as well, just like the toll. Sometimes two-plus will be free. Other times only three-plus will be free.

The state is still trying to figure out how this will work, but in order to drive for free in the HOT lane on I-405, you will need to get a transponder, or “Good To Go” pass. That’s the only way to avoid paying a toll, if you have the right number of people in your car.

Even if you have the right amount of people to drive for free, if you don’t have a transponder, you will get a toll bill in the mail, and you will have to pay it just like on the 520 bridge.

The state is currently testing a new Good To Go pass that drivers can flip between toll mode or carpool mode, depending on how many people are in the car.

But if you’re thinking, “What’s to stop me from keeping the pass in carpool mode and blowing-off the toll?” The windshield side of the pass, the one visible from the outside of the car, changes colors based on the mode so state troopers will be able to spot and bust you.