A law passed in 2001 already requires courts to order ignition interlock devices for people convicted of two or more drunken driving offenses. The devices prevent a vehicle from starting unless the driver blows into a special gauge without registering alcohol.

Gov. Matt Blunt contends judges aren't aggressively enforcing the requirement.

The bill sent to Blunt would grant the Department of Revenue a means of encouraging the devices. Repeat drunken drivers could not have their licenses reinstated without proof they had equipped their vehicles with ignition interlock devices.