This is a program for severe offenders, and is required after a second major driving offense (such as DUI). In this program, a device is attached to the offender's car which prohibits it from starting unless the offender is alcohol free. The offender must blow into this device before he starts his car. The equipment logs the offender's blood alcohol level during each use, and detects any tampering that was done to the interlock system.

Additionally, while driving the offender will be required to give a breath sample every 5-20 minutes. If the offender tests positive while driving, the car's horn will sound, and its high beam lights will flash on and off. Any tampering with the interlock system by the offender (class I misdemeanor) will cause the offender to be sent back to court as non-compliant. The offender could spend as much as two (2) years in jail for this tampering, as well as paying a heavy fine.