Over the past decade, states have increasingly turned to a powerful tool to stop drunken driving before it starts: miniature breathalyzers, wired into a car’s electronics, that prevent the engine from starting unless the person behind the wheel is sober enough to drive.
These devices, called ignition interlocks, have been remarkably effective. One study found that states mandating them for all drunken-driving offenders had 15 percent fewer fatalities from alcohol-related car accidents.
But while interlocks have prevented thousands of crashes, they have also caused them. Rolling retests, occur at random. They require the driver to lift a hand off the wheel, pick up the device and blow — hard — into its mouthpiece for several seconds. If the driver fails or doesn’t comply, the car goes into panic mode: Its headlights flash and its horn honks until the driver turns off the engine.
Read the article at The New York Times.