Convicted drunken drivers who get behind the wheel anyway may find themselves walking or catching a taxi.

An electric interlock approved by the Idaho Legislature last winter now is available for the courts. Drivers must blow into the device much the same as a police breathalyzer test. If they fail the test, the car will not start."Success has been way beyond our expectations," said Richard Freund, representing Guardian Technologies. He addressed the Idaho Board of Transportation on Friday.

Lawmakers added a $15 fee to the fine for convicted drunken drivers to pay for the locks, and on Friday, judges were allowed to sentence people to use them.

The computer can be programmed to different blood-alcohol levels or can require a check once on the road.

"It keeps problem drinkers out of trouble," Freund said. "It forces people to face their drinking problem. It is a constant reminder, and people have to deal with it."

Repeat offenders would be the most likely candidates for the device, 4th District Magistrate E. Kay Hamilton said.

"You would absolutely want to use it on the defendant who is in for the second or third time," she said.

Drivers could be ordered to have the box installed and checked every 60 days for tampering. Cost of installation is $50 and its use would run $50 a month. The state has a $6,000 fund to buy the interlocks.

About 2,500 cars in the nation have been equipped with the test equipment, Freund said. Of those, 5 percent of the operators tampered with the device or failed to comply with checks. Seventeen people were rearrested for drunken driving.

Motorists could get around the device by push-starting or hot-wiring their cars, Freund said.

"It's not a cure-all by any means," he said. "But it has worked better than anything else in fighting repeat drunken drivers."