About half of the 85,000 old Pikepass transponders are being deactivated as the windshield-mounted toll units are being removed from use.
The Turnpike Authority on Friday deactivated about 40,000 units out of 85,000 still in use. The agency is shifting to a new system that uses a windshield sticker as a method of payment for users of the Oklahoma Turnpike.
Motorists with deactivated transponders can be pulled over and ticketed while traveling on the state's 10 toll roads.
The agency has deactivated units for people who have received their fifth notice that the change is being made. About 45,000 users have more time to make the switch to the sticker system.