American Notes INVENTIONS

The crusade against drunk driving has gained an ingenious new weapon: the breath-test ignition lock. The auto's ignition is linked to a breath-alcohol measuring device, and it becomes impossible to start a car unless the driver is sober. Already used in some states, including Ohio, Maryland and Michigan, and pending in a dozen or so others, the locks will undergo their first systematic trial in California by summer.

Intended as an alternative to jail terms and suspended licenses for drunk drivers, the locks have mouthpieces into which drivers must exhale to measure their breath-alcohol level. The manufacturers, Guardian Interlock Systems of Denver and Safety Interlock of Carmel, Calif., claim that built-in safeguards make it difficult for drivers to use compressed air or borrow a breath of fresh air from a friend. One unsolved problem: how to prevent a tipsy driver from borrowing a car that has not been drunkproofed.