After reviewing 15 scientific studies on using ignition interlocks to interlocks help prevent drivers who were previously arrested for driving while intoxicated (DWI) from being re-arrested, researchers in the Centers for Disease Control and Prevention's Community Guide say it works.
The CDC now recommends widespread use of interlocks by the states; and ignition interlocks use for all drivers convicted of a DUI, including first time convictions.
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.
Researchers found that after these devices were installed, re-arrest rates for alcohol-impaired driving decreased by a median of 67 percent relative to drivers with suspended licenses.
Interlocks are most often used to prevent impaired driving by people who have already been convicted of DWI. They may be mandated through the court system or offered as an alternative to a suspended driver's license.
Impaired-driving crashes resulted in nearly 11,000 deaths in the United States in 2009-nearly one third of all traffic deaths. The annual cost of impaired driving is more than $110 billion.
"Each day, more than 30 people die because of alcohol-impaired driving.
We know that interlock devices can save lives," said CDC Director Dr. Thomas R. Frieden. "More widespread use of ignition interlocks will reduce alcohol-related crash deaths and injuries."
As of December 2010, 13 states require interlocks for all convicted offenders, including a first conviction. More than half of all states, including Missouri, require some offenders-such as those with multiple convictions or an extremely high BAC at the time of arrest-to install ignition interlocks.
In Missouri, if you have more than one alcohol related driving offense on your record, the Dept. of Revenue requires that drivers pay have the device was installed by a certified vendor before reinstatement of full, limited or restricted driving privileges.
The researchers say greater use of interlocks will be needed if they are to meet their potential for reducing impaired driving.
"When offenders' licenses are suspended, they aren't legally able to provide transportation for themselves and others who may rely on them to get to places like school and work," said Randy Elder, Ph.D., scientific director of systematic reviews with the Community Guide branch and lead author on the review. "Ignition interlocks allow offenders to keep operating their vehicles legally. At the same time, they effectively ensure that they do so more safely-not under the dangerous effects of alcohol."