Tennessee is one of several states in the nation that require all convicted drunk drivers to have an ignition interlock device installed on their vehicles. This may be one reason why the drunk driving fatality rate in the state decreased by 3.1 percent from 2012 to 2013, as reported by Mothers Against Drunk Driving. Studies show that ignition interlock devices are responsible for lowering the number of people who are arrested for multiple DUIs by up to 67 percent, according to the Centers for Disease Control and Prevention. So how do these machines work to lower motorists’ risk of becoming involved in a drunk driving car accident?

Ignition interlock devices are similar to roadside breath tests, as they use a driver’s breath sample to determine his or her blood alcohol content level. If the driver’s BAC level is over a preset limit, which is usually 0.02 percent, the car will lockup for a period of time before the driver can attempt a restart. Once the vehicle starts, the driver is prompted to blow periodic breath samples into the device to ensure they are not intoxicated.

Surprisingly, up to 75 percent of DUI offenders who have had their driver’s licenses suspended continue to drive amongst motorists on the road. IIDs help to keep drunk drivers from operating a vehicle. In fact, DUI offenders who use IIDs in their vehicles are less likely to reoffend even after the device is removed. As a result, interlock devices have saved the lives of countless people in Knoxville and across the entire state.