Reliable interlocks to detect drunken drivers remain years in the future

In most states, some people convicted of drunken driving can start their cars only after blowing into a device attached to the vehicle that detects alcohol, shutting the car down if it does. These alcohol interlocks are a bit clunky and very intrusive.

But with improvements to the technology, where a simple touch of the steering wheel might measure a driver's blood alcohol concentration level, advocates say every car, not just ones owned by those convicted of drunken driving, could someday be equipped with an interlock.

The advocates said that if the technological and privacy hurdles were overcome — which could take many years, if not decades — the interlocks could save thousands of lives a year.

"It's better to prevent somebody from breaking the law, and maybe killing or injuring someone, than to arrest them after the fact and try to prevent them from doing that again," said Anne McCartt, senior vice president for research at the Insurance Institute for Highway Safety. The institute estimates that 9,000 lives could be saved if drivers with a blood alcohol level of 0.08 or more were prevented from driving.

The National Highway Traffic Safety Administration said that 40 percent of traffic deaths were alcohol-related. More than 17,500 people died in 2006 in accidents involving alcohol, 13,470 of them in crashes where at least one driver or motorcyclist was beyond the legal blood alcohol concentration limit of 0.08 gram a deciliter, according to the agency's data.

The toll has led Mothers Against Drunk Driving to push for increased use of interlock technology, urging courts to use interlocks for first-time drunken driving offenders, not just for repeat offenders. New Mexico has been a leader in the interlock effort, recently mandating that first-time offenders receive interlocks. Louisiana and Illinois also adopted harsher interlock laws, said Kathryn Heineman, the St. Louis affiliate director of MADD.

Barry Steinhardt of the American Civil Liberties Union does not object to interlocks as an alternative to incarceration for convicted drunken drivers. But he said that putting them in all cars might be a problem depending on how the requirement is applied and how accurate the system is.

"The question is going to be, Who's going to be barred from driving and why?" he said.

Sarah Longwell, managing director of the American Beverage Institute, a Washington trade group representing restaurant and bar owners, said that it was legal for people to drink moderately and still drive home, but added that right could disappear if interlocks that turn out to be over-sensitive were required for all cars.