My Ignition Interlock Requires a Test While Driving – Is that Dangerous?

If you’re unfamiliar with ignition interlock devices — those  in car breathalyzers that prevent a vehicle from starting if the driver has been drinking — you might think that they’re easy to bypass. “Just have a friend blow into it,” people say. “Or start the car while you’re sober, and then leave the motor running while you’re at the bar drinking.”   State regulations require that all people who have an interlock in their vehicle take tests while the car is in motion.  These are known as “random re tests.”

After you have passed the initial test and begin driving, the device will require you to blow into it again.   LifSafer devices give an audible alert and the driver picks the handset up and blows.   There is  time (determined by state regulation, but usually between 3 and 5 minutes) between the alert and the need to test for you to pull safely off the road and test.   There is no need to look at the device while testing.    If you fail or refuse this random re-test, alarms will sound — the horn will honk and lights flash, but the vehicle will continue to operate.  An interlock will NEVER interfere with the operation of the vehicle once it is started.

Rolling retests can be one of the most unexpected parts of driving with an interlock. How often random re-tests are required is set by state regulation.      At LifeSafer, many of our employees field test our devices so we can fully understand our customer’s experience.   We recommend practicing with your ignition interlock when its first installed by taking short drives in familiar locations or in a large parking lot and taking the random retest until it becomes second nature.