Many people who have never been arrested for DWI have no idea what an ignition interlock is. It’s just not part of their world, and that’s fine.
But ignition interlocks, devices which keep a vehicle from starting if the driver has alcohol on his or her breath, are in the news. 25 states now require the devices for all DWI offenses, including first offenses. It’s apparent from the reader comments one reads on news sites that there are a lot of mistaken ideas about car breathalyzers, some of them pretty persistent.
Here are the facts to put these ignition interlock myths to rest, once and for all:
- I can get a sober friend to start my car for me. We’ll leave aside the question of what kind of “friend” would let you drive drunk. The fact is that the interlock device will require another test after a few minutes – the “rolling re-test.” If your “friend” wants to drive along with you, rather than do the driving him- or herself, then your “friend” has problems.
- The device will shut off my car while you’re on the highway. The only part of the car the ignition interlock can affect is the starter. Once you’re going, it won’t every shut off your car. If you fail the rolling re-test, then your horn and/or lights will turn on. But you’ll never, ever be shut down while driving.
- They’re easy to bypass. It takes as much expertise to bypass an interlock as it does to
install it. And even if you managed it, the data is logged and sent to the authorities. So if it records that you drove without a passed test, you’re in violation. So there’s really no such thing as bypassing an interlock. - They’re fussy and hard to use. A well-designed high-tech device such as Monitech’s is easy to use, once you’ve been instructed in the proper use. Most aborted tests are due to incorrect blowing, but if you learn to do it property you’ll be fine.
- They’ll drain my battery. All electronic devices use a little bit of juice: car alarms, radios, clocks, and remote starts.
If your battery is good and your alternator is functioning properly, you’ll have no problem. This should be the case with your car whether or not you have an ignition interlock installed. - No one else can use my car. Anyone can drive your car with an ignition interlock installed. However, keep in mind two things: a.) They must learn the proper operation of the interlock, and b.) You are responsible if they fail a breath test. So be careful whom you lend your car to.
- I’ll fail the breath test because I smoke.
Modern interlocks are alcohol-specific. Cigarette smoke contains a lot of things, but not alcohol, so you’re all right.
Drunk driving is a serious problem, and we need every means at our disposal to reduce the number of deaths and injuries on the road. Ignition interlocks are proven to do just that: 
states that mandate the devices for all drunk driving offenses see impressive downturns in the number of alcohol-related road deaths. So let’s learn the facts – and spread them around – so that these myths don’t obstruct efforts that really help save lives.