An ignition interlock device is often installed under a court order for someone who has been caught driving under the influence (DUI). It acts as a safety tool to ensure the driver stays sober while operating a vehicle.
The process usually begins after a DUI conviction, where the judge or the Department of Motor Vehicles may require the person to complete ignition interlock installation as a condition for getting back limited or full driving privileges.
This article will help you understand what an ignition interlock device is, how it works when it’s required, and what you can expect if you need to use one.
What is the exact usage of an Ignition Interlock Device?
An Ignition Interlock Device (IID) is a small electronic device that is installed in a vehicle to stop someone from driving under the influence of alcohol. It works like a breathalyzer. The driver must blow into the mouthpiece of the device before starting the car. If the device detects that the blood alcohol concentration (BAC) is higher than a preset limit (usually around 0.02% or lower), the car will not start.
Because of this function, the IID is sometimes called a car breathalyzer or a blow-and-go device.
When is it required?
Ignition interlock devices are usually ordered by a court or required by the state’s Department of Motor Vehicles (DMV) after someone is convicted of a DUI (Driving Under the Influence) or DWI (Driving While Intoxicated).
Depending on the severity of the offense, the driver may have to install the device in their car for a few months or even several years. Some states require it for first-time offenders, while others only mandate it for repeat offenders or high BAC levels.
How does the device work?
Here’s how an IID typically works:
- Blow to start – Before starting the vehicle, the driver blows into the mouthpiece.
- BAC test – The device checks the BAC level in the breath sample.
- or fail – If the BAC is below the legal limit, the engine starts. If not, the engine remains locked.
- Rolling retests – While driving, the device may ask for additional breath samples. This ensures the driver remains sober throughout the trip.
If a driver fails a rolling retest, the car won’t stop immediately (for safety reasons), but the failure is recorded and may trigger alarms like honking or flashing lights.
Where can it be installed?:
You must go to a state-approved service provider for ignition interlock installation. These providers install the device and also train you on how to use it. The installation process takes about 1-2 hours, depending on your vehicle’s make and model.
You’ll also need to return to the service center regularly (usually every 30–60 days) so they can the device’s data and check for any violations or issues.
Benefits of Ignition Interlock Device:
While it might feel like a punishment, using an IID can actually be helpful. It gives drivers the ability to continue driving legally while proving they are sober behind the wheel. It also reduces the chances of repeat DUI offenses and helps keep roads safer for everyone.
While it may seem like a burden, it’s actually a tool that s safe driving habits and allows many individuals to stay on the road legally. By following the rules, attending service appointments, and staying sober behind the wheel, a person can fulfill the legal requirements and take meaningful steps toward regaining driving independence.
