Breathe Before You Weave

In the widespread efforts to round up drunken drivers, more and more motorists are being confronted by a piece of law-enforcement technology called the blood-alcohol tester. Several companies are competing to fill the demand for these devices as police departments equip their officers for tactics like spot-check roadblocks.

The machines have come a long way in speed and accuracy since the days when suspects were asked to blow into a glass vial for a wet chemical test. The latest version of Smith & Wesson's $4,300 Breathalyzer measures the level of alcohol in a suspect's blood by projecting an infrared beam through a sample of breath blown into the machine. Massachusetts State Police, whose arrests for drunken driving in the past three months have increased 48% over last year, bought 35 of the new Breathalyzers in August.

Other products are even more portable and flexible. Intoximeters Inc. of St. Louis produces the transistor radio-size Alco-Sensor, which is being used for roadside tests by police in cities like New York. The $390 device gives a digital readout when the suspect breathes into its plastic mouthpiece. In July, Allstate Distributors of Marietta, Ga., introduced a coin-operated tester for use in taverns.

The patron blows into the $2,495 machine through a disposable straw. If the user is over the legal limit, the machine flashes a red-light warning that says, DON'T DRIVE. What happens after that is between the drinker and his conscience. This file is automatically generated by a robot program, so viewer discretion is required.