Is Threat of Ignition Interlock Device the Key to Curtailing Drunk Driving?

Researchers find drunk drivers are less likely to operate a vehicle if they face installment of an ignition interlock device upon DUI conviction.

The use of ignition interlock devices for DUI offenders has been put in place in every state. 22 states mandate ignition interlock devices for first time DUI offenders. Other states reserve the devices for repeat offenders or offenders who were found with higher blood alcohol content (BAC) upon arrest for driving under the influence. Some states leave employment of an interlock device to judicial discretion.

A recently released study conducted by the Johns Hopkins Bloomberg School of Public Health found that the use of ignition interlock devices is proving very effective in reducing drunk driving. In fact, the study reports a 7 percent reduction in traffic fatalities for states that have mandatory ignition interlocks for first time DUI offenders.

In states with mandatory interlock laws, everyone convicted of a DUI is required to have an ignition interlock device installed in their vehicle. They then have to blow into the breath-testing device every time they want to start their car. The breath-test devise is connected to the vehicle’s ignition and the vehicle will not start unless the driver blows below a pre-set blood-alcohol content (BAC) limit. The pre-set BAC limit is usually .02. Advocacy group Mothers Against Drunk Driving (MADD) estimates that installing the interlock devices costs between $70-$150 and monitoring by a commercial service costs between $60 and $80.

The report of ignition interlock device program effectiveness comes at a time when drunk driving statistics have reached staggering levels. In 2015, there were 35,092 traffic fatalities in the U.S. One third of the drivers in these crashes had been drinking. Of the one third, 29% were found to be legally drunk and 20% had BAC almost twice the legal limit or higher.

The Center for Disease Control and Prevention (CDC) acknowledges the effectiveness of ignition interlock devices in reducing the number of drunk drivers on the road and advocates for the promotion of programs that encourage an increase use of these devices. The CDC has also laid out several suggestions for States to adopt in order to increase the effectiveness of ignition interlock device programs. These suggestions include:

• Require or incentive device use
• Impose strong penalties for individuals failing to comply with the program
• Ensure proper device use through monitoring
• Uniformly implement program terms across the state
• Coordinate across agencies
• Educate stakeholders about the program
• Provide adequate program funding
• Utilize data to evaluate program and its effectiveness