The use of IIDs after a DUI conviction in California

After a DUI conviction in California, a driver may be required to install and use an ignition interlock device for a period of time.

Californians know that their state is tough on drunk driving. While certainly it is important to keep people safe on the roads, it is equally important for the rights of those arrested for drunk driving to be treated fairly. An arrest does not mean a driver is guilty of a DUI charge and the defense process is intended to give innocent people a way to avoid unnecessary convictions.

When a person is ultimately convicted of a DUI in California, however, several penalties may be ordered. Among these can be the required installation and use of an ignition interlock device. This commonly accompanies an order for a revocation or suspension of driving privileges. Once these privileges are reinstated, the IID must be utilized for a given period of time.

The California Department of Motor Vehicles can also require drivers to install and use ignition interlock devices in other cases. This includes the operation of any vehicles while under suspension or revocation due to a previous drunk driving conviction.

What exactly is an ignition interlock device?

As the name suggests, an IID can essentially put a lock on a vehicle's ignition. This lock can only be undone with a successfully passed breath test. A complete IID system is comprised of a unit that mounts on a dashboard, close in size to a smartphone, and a microchip that is installed in the ignition system.

The dash unit is used to collect a breath sample from the driver. The results of this sample are sent to the microchip. If the sample shows an alcohol content above the allowed limit, the ignition will remain locked. If the sample shows an alcohol content below the allowed limit, the ignition will then unlock. It is at this point only that a person can operate that vehicle.

Drivers who must use IIDs have to pay authorized installers to have the units put into their vehicles. After that, they must then give the court proof that the installation has been completed. Authorities can monitor all data collected by the IID.

Evolving technology may change IIDs

Research has been underway by the Driver Alcohol Detection System to explore additional types of ignition interlock devices. One system in testing collects alcohol level data by touch rather than by breath sample. According to, the dash units in current IIDs would be replaced by special sensors in steering wheels.

Congress has also voiced its support for building IID functionality directly into new cars, trucks and SUVs. adds that some manufacturers are considering doing just this.

What does this mean for drivers?

The cost, inconvenience and even embarrassment of using an ignition interlock device are just some of the ramifications of a DUI conviction in California. Anyone who has been arrested for a DUI should talk to an attorney to learn how to defend themselves against these charges.