CHICAGO (CBS) — If Indiana is any indicator, it might end up costing the state of Illinois much-needed revenue if the governor signs off on legislation to raise the speed limit on most Interstate highways and tollways to 70 mph.

WBBM Newsradio’s Mike Krauser reports, last year, part of the Indiana Toll Road – roughly between Lake Station and the Illinois border – had its speed limit raised from 55 to 70 mph, and now state police are writing a lot fewer tickets.

Indiana State Police Sgt. Tim Moon said speeding ticket revenue was cut in half on that stretch of the toll road, as the number of tickets issued by police dropped from 6,700 to about 3,300.

Now, while police are still using marked cruisers, they also have unmarked Ford Mustangs and Dodge Chargers, and at least one unmarked pick-up truck to catch unsuspecting speeders in the act.

Gov. Pat Quinn’s office has said he has safety concerns about raising the speed limit.

Illinois State Police and the Illinois Department of Transportation both oppose the higher speed limit.

The legislation would allow Cook, DuPage, Kane, Lake, McHenry, and Will Counties – and two counties near St. Louis – to opt out of the higher speed limit.

The top speed limit in the state is currently 65 mph, though most highways in the Chicago area and near other urban areas have a 55 mph speed limit.

The House and Senate both approved the measure with enough votes to override a veto, should the governor oppose the legislation. If signed, it would go into effect Jan. 1.

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