It could be more expensive for drivers to use the new Highway 99 tunnel — once it’s finished — than originally thought.

Patty Rubstello, Washington State Department of Transportation’s assistant secretary for tolling, told KIRO 7 the tolls could reach $2.50 during peak hours. That’s double the $1.25 for peak times that a 2014 panel suggested.

“We are in the process of developing a new model that the commission will use when they get ready to do rate-setting, but we’re not there yet,” she explained.

The 2014 recommendation was based on outdated traffic data from 2006, Rubstello said. The new model calls for off-peak rates between $1 to $1.50.

While the rates will likely be higher than previously thought, Rubstello pointed out they’ll be much lower than what drivers pay along State Route 520 and I-405.

The state Transportation Commission will set the toll rates for the 99 tunnel.

The state will have to charge enough to raise $200 million to help pay for the project. However, the tunnel will likely open without tolls at first, Rubstello told KIRO 7.

Adding tolls to Highway 99 will make it that much more difficult for Western Washington drivers to get around quickly without paying extra. Tolls already exist for the 520 Bridge, Tacoma Narrows Bridge, State Route 167 HOT lanes and the I-405 express toll lanes.

The state continues to make adjustments to its tolling system. On Tuesday, the Transportation Commission approved permanent changes to the I-405 system that limits toll collection to weekdays (5 a.m. to 7 p.m.). On weekends, weeknights, and major holidays the toll lanes are free. Drivers won’t notice a difference, as these tolling limits have been in place on a temporary basis.

Additionally, Washington Gov. Jay Inslee announced a series of changes to the I-405 corridor earlier this year — that included the removal of tolls during certain time periods. Inslee noted more than 14 changes.

“This is a learning process the entire state is undergoing,” he said.

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