What are ignition interlock devices?

In North Carolina, and in many other states across the nation, people charged with certain DWI violations must have an ignition interlock device installed in their vehicles.

If you have had your driver’s license revoked as a result of a DWI conviction, you may receive restricted driving privileges after having an IID installed in your vehicle. This may help to provide essential transportation to work, school, court appointments, doctor’s appointments or other necessary errands.

How do interlock devices work?

Technicians wire the interlock machine into the vehicle’s ignition system. The device contains a camera and monitor that sit on the dashboard of the car. Before the car will start, the driver must blow a breath sample into the machine, which will then measure your blood alcohol content level. If the blood alcohol concentration reads below the preset limit, the car will start. Periodically, the driver must blow into the breath test monitor while driving in order to keep driving. If a rolling retest reads above the preset limit, the car will power down.

What you should know

According to North Carolina legislation, the court will require an ignition interlock device under the following circumstances:

• The driver has had multiple impaired driving offenses over the past seven years
• The driver had a BAC level of 0.15 or higher
• The driver previously abused restricted driving privileges

The device must remain installed in the vehicle for one, three or seven years depending on the details of the situation and the severity of the violation. Furthermore, the interlock device stores information, such as startup attempts, attempted removal of equipment, BAC readings and lockouts, and then transmits the data to law enforcement during mandatory maintenance appointments.

If you know how interlock devices work, you may be able to receive restricted driving privileges until the state restores your driver’s license.