Ignition interlocks curb number of repeat arrests for convicted drunk drivers, study finds

It’s not easy getting drunk drivers off the road. But gadgets known as ignition interlocks, which sample a driver’s breath before the vehicle can start, might help. A new study suggests that such devices reduce re-arrest rates for people previously convicted of drinking and driving.

Reseachers reviewed 15 reports published through 2007 about the use of ignition interlocks and re-arrest rates. “The installation of ignition interlocks was associated consistently with large reductions in re-arrest rates for alcohol-impaired driving within both the earlier and later bodies of evidence,” the study says. “Following removal of interlocks, re-arrest rates reverted to levels similar to those for comparison groups.” The study appears in the March issue of the American Journal of Preventive Medicine.

How do the devices work? Here’s an explanation from the Centers for Disease Control and Prevention:

“Ignition interlocks are devices that can be installed in vehicles to prevent someone from operating a vehicle with a blood alcohol concentration (BAC) above a specified level. This level is usually 0.02 to 0.04 grams per deciliter (g/dL); the minimum illegal BAC level is 0.08 g/dL in every state. The devices work by sampling the driver’s breath before the vehicle can be started and periodically while it is operating.”

Based on the study’s findings, the CDC seeks wider use of ignition interlocks and urges using them even for first-time offenders. Crashes caused by impaired drivers accounted for nearly 11,000 deaths in the United States in 2009, the CDC says. Check out these statistics and guidelines from the CDC about impaired driving.

Currently, the report says, only a small number of repeat offenders participate in the interlock program and just 13 states require them to do so.