When someone is convicted of a DUI, the court may require that a person convicted of a first offense violation of Section 23152 or 23153 to install a certified ignition interlock device on any vehicle that the person owns or operates and prohibit that person from operating a motor vehicle unless that vehicle is equipped with a functioning, certified ignition interlock device. The court shall give heightened consideration to applying this sanction to a first offense violator with 0.20 percent or more, by weight, of alcohol in his or her blood at arrest, or with two or more prior moving traffic violations, or to persons who refused the chemical tests at arrest.

If a person is convicted of a violation of Section 23152 or 23153, and the offense occurred within 10 years of one or more separate violations of Section 23152 or 23153

that resulted in a conviction, the person may apply to the Department of Motor Vehicles (DMV) for a restricted driver's license that prohibits the person from operating a motor vehicle unless that vehicle is equipped with a functioning ignition interlock device. The restriction shall remain in effect for at least the remaining period of the original suspension or revocation and until all reinstatement requirements are met.

If the court orders the ignition interlock device restriction, the term shall be determined by the court for a period not to exceed three years from the date of conviction. The court will notify the DMV, who will place the restriction in the DUI offenders driving records. The records of the department shall reflect mandatory use of the device for the term ordered by the court.

While the court will order the installation of the ignition interlock device, but it is up to the DUI offender to get it installed. There are many reputable, licensed companies who will work with the DUI offender in payment options and in making the process as easy and hassle-free as possible. The installation of the device is simple: it is a relatively small device, about the size of a handheld radio, which is electronically connected to the ignition of the vehicle. In order to start the engine, the driver breathes into the unit for several seconds. The device measures the level of alcohol on the breath and compares it to predetermined limits. If the breath alcohol (BAC) is over the authorized limit, the vehicle won’t start. However, if the BAC is within the allowable range, the car starts. Most ignition interlock devices have an added requirement to take periodic re-tests, calling “rolling retests." Rolling retests check the BAC while driving in order to assure that the driver is not driving while intoxicated. This also rules out the possibility that the driver would have someone else give the initial breath sample, because the repeated tests require a consistent sample in the predetermined range while driving.

Each vehicle with an ignition interlock device has to be serviced by the installer at least once every 60 days in order for the installer to recalibrate the device and monitor the operation of the device. The installer will notify the DMV if the device is removed or indicates that the person has attempted to remove, bypass, or tamper with the device, or if the person fails three or more times to comply with any requirement for the maintenance or calibration of the ignition interlock device.