Ignition Interlock Device (IID)

An ignition interlock device (IID) requires a driver to breathe into the device prior to starting their car. If the IID detects the blood alcohol concentration (BAC) of the driver is above the programmed limit, then the engine of the vehicle will not start. Drivers who have been arrested and convicted of DUI may be required to install an ignition interlock device as a condition for reinstating their driver's license after a license suspension or as part of a DUI diversion program. The amount of time the IID is required varies by offense and by state law. Drivers should not attempt to trick or circumvent the ignition interlock device.

Installing an ignition interlock device can be costly, although prices vary throughout the U.S. Installation could cost over $100 and additional monthly fees are required. While the IID is generally effective at preventing drunk driving, critics argue it is an imperfect solution. Many critics suggest the IID requirement is not fairly and appropriately applied and little has been done to ensure uniform administration of the program throughout some states.