California DUI

Ignition Interlock Devices

What The Ignition Interlock Device Does
The Ignition Interlock Device (IID) is in-car/vehicle alcohol breath screening device that prevents a vehicle from starting if it detects a blood alcohol concentration (BAC) over a pre-set limit of .02 (i.e., 20 mg of alcohol per 100 ml of blood). Also known as a breath alcohol ignition interlock device (BIID), the ignition interlock device is located inside the vehicle, near the driver’s seat, or installed in a vehicle’s dashboard.

The Ignition Interlock Device is similar to a Breathalyzer, but is connected to the engine’s ignition system. The driver must breathe into the device before starting a vehicle equipped with an ignition interlock device, and the device will not let the vehicle start, if it measures a blood alcohol concentration (BAC) more than the programmed blood alcohol concentration in the device, which is commonly .02 or .04.

Once the vehicle is started, the ignition interlock device will require the driver to provide breath samples at random pre-set times while the engine is running. If a sample is not provided, or if the measured BAC exceeds the limit, the device will issue a warning, record the event, slowly bring the car to a halt and activate specific alarm systems (e.g., lights flashing, horn honking, etc.), until the ignition is turned off. However, the interlock device will not turn off the engine if alcohol is detected as this creates an unsafe driving situation.

How Ignition Interlock Devices Work
The ignition interlock device uses an ethanol-specific fuel cell for a sensor. The fuel cell sensors in the devices are electrochemical devices in which alcohol undergoes a chemical oxidation reaction at a catalytic electrode surface (platinum) to generate an electrical current. This current is then measured and converted to a blood alcohol concentration. The fuel cell technology used in the ignition interlock devices is not as accurate or reliable as infrared spectroscopy technology used in evidential Breathalyzers, but the technology is cheaper. The fuel cell technology of ignition interlock devices is more specific for alcohol, therefore has fewer of the specificity issues associated with infrared spectroscopy.

You can find ignition interlock devices manufactured by a number of manufacturers, such as LifeSafer Interlock, Guardian Interlock, Smart Start, SOS, Ignition Interlock Systems, Intoxalock and Monitech. However, the federally approved ignition interlock devices are maintained by the National Highway Traffic Safety Administration in their NHTSA Conforming Products List.

An ignition interlock device keeps complete track of the activities on the device and the interlocked vehicle’s electrical systems. The records or logs of the devices can be printed out or downloaded each time the devices’ sensors are calibrated. The sensors are often calibrated after 30, 60, or 90 day intervals. The ordering authority (court, probation, department of motor vehicles or other government agency) may require periodic review of the log, and if violations are found, additional sanctions or penalties can be imposed.

Often, ignition interlock devices are imposed as penalties for drivers convicted of driving under the influence, particularly for frequent offenders. The installation of ignition interlock device is mandated by many state laws in the U.S. Most of the U.S. states allow law to order the installation of ignition interlock devices as penalties for repeat offenders, and for first offenders in some states. In California, a driver convicted of a second offense must install an IID after serving the first year of the license suspension, it may also be ordered in other circumstances.

The Ignition Interlock Controversy
The mandatory installation of ignition interlock devices has spurred a controversy over the devices. Advocates of IIDs including politicians in Sweden, Japan, Canada, the U.S., and other countries, are in favor of installing these devices as standard equipment in all motor vehicles sold. Frequently there are proposals in favor of mandatory IID installations for all offenders. The Mothers against Drunk Driving (MADD) in November 2006 launched a highly publicized campaign advocating the mandatory installations of IIDs for all first offenders.

The critics of ignition interlock devices view the devices as inaccurate, ineffective and dangerous. The controversy compelled the “California Department of Motor Vehicles” to conduct a study to “Evaluate the Effectiveness of Ignition Interlock in California.” According to the California Study, the ignition interlock devices are not effective in reducing DUI convictions or incidents, after being imposed for first-time DUI offenders. The study however revealed that the risks of crashing were higher for offenders with these devices installed in their vehicles; it was perhaps because they were being asked to conduct breath tests while driving.