How ignition locks work

Insert key into ignition

Turn key on

Display screen will show "warming up" message

Turn key off to take breath test

Driver blows into mouthpiece of device

Device studies the breath sample for alcohol

Results displayed on screen

If driver's blood alcohol content is 0.05 or lower, they have a period of one or two minutes to start their vehicle

If driver fails, the ignition will not start, and the device will report a violation

At random intervals during driving, the interlock will ask for a rolling retest -- and if the driver fails or ignores the test, the car's lights will blink and horn will sound.