A person convicted of an impaired driving offense in North Carolina may have his or her driver’s license suspended or revoked depending on the circumstances of the case.

Some situations allow the person to reinstate the driving privileges by installing and using an ignition interlock device for a stipulated period of time. A person considering this option should learn how an IID really works.

IID components

An ignition interlock device includes multiple components. As explained by Intoxalock, a provider of IIDs, the system includes a handheld unit into which a person provides breath samples. That device connects to electronic elements installed into the dash that control the vehicle’s ignition and transmit data with test results. Some systems come with cameras that record video footage of all tests.

Starting a vehicle

Before every trip, a driver must pass a breath test. Only once this happens will the ignition unlock, allowing the driver to start the vehicle.

Driving with an IID

After a vehicle has been started and a person is driving, more tests may be required. Called rolling retests, these happen at random intervals so a driver cannot plan for them. The intention is to prove that the person does not begin drinking after starting a vehicle. If a driver fails a rolling retest, the horn may honk, and the lights may flash until the person stops the vehicle and turns off the ignition.

This information is not intended to provide legal advice but is instead meant to give residents in North Carolina an overview of how ignition interlock devices work and when a driver may be required to perform a breath test.