Ignition Interlocks: Turn the Key and Blow

Looking around for new weapons to combat impaired driving, states have rediscovered a forgotten ally: the ignition interlock. And it’s not the ignition interlock of the 1980s, with all the concerns about how easy it was to defeat the device. This model is kicked-up, high-tech and ready to go.

For decades, drunk driving fatalities steadily decreased every year, as states adopted stricter standards and harsher penalties. But progress has stalled in the last five years, as the percentage of alcohol-related traffic deaths has remained constant, near 40 percent. Enter the high-tech ignition interlock.

Chuck Hurley, CEO of Mothers Against Drunk Driving (MADD) says we need to get serious about drunk driving and that ignition interlocks are the tool of choice for greater progress. With more than 16,000 alcohol-related fatalities every year, drunk driving is “still the most tolerated, frequently committed violent crime in America. We need to stop the ‘catch and release’ approach by the courts, make ignition interlocks required for all convicted drunk drivers, and work for advanced technology that will not allow drunk drivers to start their vehicles.”

The premise is simple: separate drinking drivers from their vehicles. For drivers with alcohol in their breath, their car won’t start.

Here’s how it works: An ignition interlock device is installed on a car and connected to the starter system. The device can be set to a specific BAC level for the offender, from .00 BAC to slightly higher levels, such as .02 BAC. When the offender wants to start the car, he or she has to blow into a breathalyzer tube. If the ignition interlock detects alcohol above the established level, the device won’t send power to the starter system, and the car won’t start.

One of the concerns on the early ignition interlocks was that an offender could start the car and then start drinking while driving. Not so with the new versions, which require periodical “rolling retests” while the car is running. As the offender drives, he or she gets a warning indicator that a test will be required soon, to give them time to pull over to more safely take the test. If they’re unable to get out of traffic, they can blow into the device as they continue to drive. The retests are random, so the offender can’t plan for them.

The rolling retests also eliminate the old gambit of driving to a bar, sober, and leaving the vehicle running while the driver enjoys happy hour. He’d return intoxicated to his car, ready to hit the road, or whatever else happened to get in his way.

As a safety feature, the ignition interlock won’t turn the motor off, even if the device measures alcohol above the set limit. While that may seem counter-intuitive, think about it this way: the only thing worse than a drunk behind the wheel is a drunk behind the wheel with no steering capability. Since steering shuts down when the engine is turned off, the devices will not shut the engine down.

Instead, the ignition interlock records a violation on a data log. In fact, it logs everything that happens with the car. It tracks all attempts to start the vehicle and the breath test results, whether the car starts or not. It records the results of all rolling retests and flags any attempt to tamper with the device.

Tampering was a problem with early models of ignition interlocks, where clever offenders could easily disable the devices. Today’s models have sealed wiring and circuitry so any attempts to bypass the device are readily apparent when the car is brought in for regular maintenance checks of the ignition interlock. The regular checkups ensure that the devices are properly calibrated and measuring alcohol accurately.

Read the full article. (Registered subscribers and NCSL members only.)

Register now! (Subscribers only.)

Subscribe now to get the rest of this article and more news from the national magazine of policy and politics, State Legislatures!