Those Ignition Alcohol Locks? Thankfully, They Work

By Blake Z. Rong | March 06, 2012
More effective than a Hollywood-chic ankle bracelet, and less communal than an Alcoholics Anonymous meeting, the alcohol interlocks on the vehicles of convicted offenders are immensely good at preventing a second DUI. Many who are convicted of a DUI tend to go out and drive drunk again, and about 31 percent of people arrested are repeat offenders, so the statistic goes. But after Washington State made interlock systems a requirement on anybody convicted of a DUI, the amount of repeat offender arrests fell by 12 percent. From January 1999 to June 2006, three-quarters of DUI arrests were first offenses. After Washington expanded the interlock laws to include all DUI offenders, the rate of repeat offenders fell drastically below the projected rate. Here's what the Insurance Institute for Highway Safety has to say about it:
The researchers found that the expansion of the interlock requirement reduced the 2-year recidivism rate for first-time simple DUI offenders by 1.3 percentage points. So, for example, in the second quarter of 2006, the last part of the study period, the recidivism rate was 9.3 percent. That is a 12 percent reduction from the 10.6 percent that would have been expected without the change. There also was an 11 percent reduction in recidivism (from 10.2 percent to 9.1 percent) among all first offenders, including those convicted of negligent driving, those with high BACs, and other types.
It's exactly what those interlocks set out to accomplish.
If you've never been foolhardy enough to have to use an ignition interlock device, here's what it is: Think of the alcohol interlock as a Breathalyzer, but for your ignition. Blow into it when you climb into your car, and if your alcohol content is above the legal limit, your car won't start. Interlocks have some problems in their fundamental design—what's to prevent a sober friend or passerby from blowing into it, for example?—but in the state of Washington, the numbers don't lie. Currently, interlocks are mandated only for people with multiple convictions or who register blood alcohol content levels of more than 0.15 percent. But Congress is considering putting them on anybody who's ever gotten a DUI, especially considering that one-third of all DUI accidents occur with a BAC below 0.15. It's the sort of perpetual battle of individual rights versus saving lives always seem to mire our government in controversy. Fifteen additional states require everybody convicted of a DUI—regardless of how high their BAC was at the time, an irrelevant figure—to install an interlock on their cars, while another 22 require them as well, but only on multiple offenders. Preventing drunk drivers on the roads is always a worthy goal, so it shouldn't be a surprise to see more interlocks on cars—until, eventually, there won't be any needed. Source: IIHS