Eight months after it was enacted, what was supposed to be a tough measure against drunken driving is having little effect in four test counties, including Sacramento.

The law requires anyone convicted of drunken driving to get an ignition interlock device, commonly known by the Breathalyzer brand name, installed on his or her car for at least five months.

The device, requiring the driver to blow into a tube, does not allow the car to start if the driver's breath shows the presence of alcohol.

As of late February, however, Department of Motor Vehicles data indicate only one out of 10 of those convicted of drunken driving since July has had a device installed.

In Sacramento County, the percentage was slightly higher, 12 percent.

In total, there have been 13,288 people convicted of DUI in the four counties - Sacramento, Los Angeles, Alameda and Tulare - since the law went into effect. Yet, state officials have confirmation of only 1,335 drivers who have had interlock devices placed on their vehicles.

DMV officials contend it is too early to assess the program. They say some people convicted of DUI lose their license for months as part of their sentencing, so would not have registered yet for the interlock devices.

The extremely low numbers, however, suggest others are driving illegally after conviction, without a valid license or a device.

The law's author, Assemblyman Mike Feuer, D-Los Angeles, on Friday said he doesn't think it is too early to look at whether the law is working or not.

Feuer said he will convene a meeting with the DMV and other state agencies in the next few weeks to "see what needs to be improved."

"Lives are at stake," Feuer said. "It's extremely important we implement this properly."

Nationally, as well, the drunken driving issue heated up last week when New Mexico Sen. Tom Udall proposed shifting some seat-belt safety funds toward research on new in-car technology to detect if a person has been drinking.

Federal officials with the National Highway Traffic Safety Administration have been studying ways in which the steering wheel, the engine start button, and dashboard sensors can detect a person's blood alcohol level.

Lobbyists for restaurants and bars reacted by saying they fear the government will put unreliable technology in all cars to "eliminate Americans' ability to have a glass of wine with dinner."

Udall said that's not the case. "The aim is to stop drunk driving, not discourage responsible social drinking," he said in introducing the bill last week.

That means technology would have to be reliable, and block cars from starting only when the driver's blood alcohol is 0.08 or higher, Udall said.