Drivers on Illinois toll roads have been digging for twice as much change since Jan. 1, while those drivers with I-PASS have cruised through automated toll booths, paying the old toll rate electronically — and watching other drivers wait in line.

The rate increase imposed by the Illinois State Toll Highway Authority will raise funds for a 10-year, $5.3 billion plan to rebuild most of the tollway system, according to the authority’s Web site.

By allowing I-PASS users to pay the old rates, the authority hopes to encourage more drivers to use I-PASS, which they say will relieve congestion at toll plazas.

The authority is “giving people a very strong incentive to buy an I-PASS,” said Ian Savage, associate chairman of Northwestern’s economics department and an appointed faculty member at NU’s Transportation Center.

“The existing way of paying your tolls is something out of two centuries ago,” he said.

Tollway officials plan to cut travel times and congestion by instituting “open road tolling,” a toll-payment system that will allow I-PASS users to avoid the hastle of toll booths altogether.

Under this system, toll plazas that currently straddle the highway will be torn down and replaced by plazas on either side of the road, with cash-paying drivers merging on and off to pay their tolls while I-PASS users zip by.

By raising tolls and encouraging I-PASS use, Illinois is tackling the problems of lower gasoline-tax revenues and increased traffic before they are too troublesome to overcome, Savage said.

“I think the tollway department is being very bold, but I think eventually you have to do this, a type of shock therapy,” he said. “As soon as you get a higher proportion of people paying electronically, you can redesign the whole highway.”

According to the Illinois Tollway’s Web site, I-PASS accounts can be opened online for $50, including $40 worth of pre-paid tolls.

Lower-income residents can activate an I-PASS for $20. I-PASS is available at many local stores, including Jewel-Osco.

Savage, who got his own I-PASS after giving a speech in the fall on highway improvement plans, said the authority is offering a “real big deal.”

“I think if you’re a regular user, it’s a no-brainer,” Savage said. “Not only do you get cheaper tolls, you get through toll booths faster.”

Reach Ryan Haggerty at [email protected].