Convicted drunk driver Matt Nunn can drive these days because his "electronic probation officer" is riding shot-gun.
"My license was suspended for two years and in order to get it back," explains Nunn, "I had to install 'this' for 18-months."
This...is his ignition interlock. Nunn blows into a breathalyzer for three seconds every time he gets behind the wheel. If his blood alcohol level is too high, he can't start his engine.
"It's a deterrent," he says, "you know it's there."
In most states, courts have the option to order interlocks in cars of convicted drunk drivers, but only do so rarely. Since one-third of drunk drivers are repeat offenders, some safety experts say it's an option not used enough.
"Interlocks are something that should be required and are something that judges and prosecutors should be looking at," NHTSA administrator Nicole Nason tells CBS News.
And they are, as more state legislatures now mandate the use of interlocks for drivers caught with a blood alcohol level above the nationwide legal limit of .08. Seven states have this year, including Nebraska, Washington, Colorado, Virginia, West Virginia, Maine and Alaska. Those states join New Mexico, Arizona, Illinois, Louisiana and Oregon that have mandated the devices since 2005. Seven more, Califonia, New York, New Jersey, Pennsylvania, Michigan, Oklahoma and South Carolina, are considering it.
"In addition to having a strong effect on fatality reductions, interlocks are now proven to have a 60 percent reduction in recidivism - that is repeat drunk driving offenses," Chuck Hurley, president of Mothers Against Drunk Driving.
But the American Beverage Institute, which represents chain restaurants, wants the interlocks mandated only for repeat offenders caught driving well above the legal limit.
"A first offender could be somebody who is just one sip over the limit," argues ABI's Sarah Longwell. "A 120-pound woman can reach .08 after having just two glasses of wine. And we don't think that she should be punished the same way as the guy who has 15 drinks and then gets into the car and drives should be punished."
Those forced to use the device pay $125 to install it and $70 a month to maintain and monitor it.
"It's less than the cost of a drink a day for the interlock, so that taxpayers don't have to," says Hurley.
With one month left with his interlock, Matt Nunn is playing it safe.
"I've never failed," he says, "because I haven't taken a drink since my last DUI."
The question is will he remain sober, when he drives solo.