Beginning December 29, a round trip during peak hours on the State Route 520 Bridge will cost some drivers $7 -- that has the Washington State Department of Transportation bracing for many people to avoid the tolls by taking the Interstate 90 Bridge instead.

"There's going to be a lot more traffic for sure," Marcia Wike of Seattle remarked.

"I suspect a lot of people who have the option of taking one bridge or another will probably take I-90 to avoid the toll," Ryan Wike said.

State projections point to the same thing.

"About 20 percent of the trips over 520 will go over the I-90 corridor, and that's going to slow I-90 in the range of 5-10 mph in peak periods," state tolling director Craig Stone said.

WSDOT said it expects another 4 percent of commuters will go north around Lake Washington and 15 percent will ride the bus.

"All the people, they will think about it -- why do I have to pay for this," Ryan Wike said.

Ryan normally drives I-90, but said he sees a scenario where the might actually switch to 520.

"I might if I-90 is so terrible that it's worth the two-fifty or whatever to save myself 30 or 40 minutes," he said.

Transportation planners said it could be several weeks before people fully sort out their commutes.

"We just want people to plan ahead and think about how they're going to cross Lake Washington," Stone said.

In the future, drivers could end up paying tolls on the I-90 Bridge, as well. The state legislature could decide in the next three years whether to pursue them.