San Francisco DUI Lawyer California DMV Hearing Attorney

• Introduction
• What To Do First
• Elements of the Offense
• BAC Calculator
• Misdemeanor DUI Case
• Criminal Jury Trial
• Criminal Court Punishment
• Alternative Sentencing
• Sentencing Enhancements
• Refusal Cases
• Felony DUI Case
• Medication Cases
• Drug Cases
• Federal DUI Case
• Out-of-State Drivers
• Drowsy Driving
• Post-Conviction Relief
• Ignition Interlock Devices
  • What is Ignition Interlock?
  • IID Technology
  • Court Ordered Installation
  • Settlement Negotiations
• Motorcycles, Boats, Planes
• California Highway Patrol
• California DUI Resources

Ignition Interlock Devices

If you are convicted of a DUI in California, or convicted of driving on a suspended license due to a DUI conviction (California Vehicle Code Section 14601.2), you may be required by the court to install an interlock on any vehicles you own or operate for a maximum of three years from the date of the conviction (California Vehicle Code Section 23575).

Ignition interlock device (IID) is a mechanism similar to a breathalyzer which is installed in a vehicle's dashboard. Before the vehicle can be started, the driver must breathe into the device. If the analyzed result is over a programed blood alcohol concentration the vehicle will not start.

At random times after the engine has been started, the IID will require another breath sample. The purpose of this is to prevent a friend from breathing into the device, enabling the intoxicated person to get behind the wheel and drive away. If the breath sample isn't provided, or the sample exceeds the ignition interlock's preset blood alcohol level, the device will log the event, warn the driver and then start up an alarm (e.g., lights flashing, horn honking, etc.) until the ignition is turned off. A common misconception is that interlock devices will simply turn off the engine if alcohol is detected; this would, however, create an unsafe driving situation and expose interlock manufacturers to considerable liability.

In the past, ignition interlock devices were not mandatory for multiple-offense drunk drivers, but they are becoming much more common in California DUI cases. New California legislation effective September 20, 2005 mandates that anyone convicted of multiple drinking and driving offenses within a 10-year period must have the certified ignition interlock device installed 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 (California Vehicle Code Section 23575).

Even on a first-time drunk driving offense, the court can order the installation of an ignition interlock device. The device is more likely to be ordered in cases where the motorist refused to take a chemical test to determine blood alcohol content (BAC), or if the motoris's BAC was .15 percent or greater. Some judges order ignition interlock devices in all DUI cases, even first offenses, if the driver’s BAC was .10 percent or greater.

Modern ignition interlock devices use an ethanol-specific fuel cell for a sensor. A fuel cell sensor is an electrochemical device in which alcohol undergoes a chemical oxidation reaction to generate an electrical current. This current is then measured and converted to an alcohol equivalent reading. Although fuel cell technology is not as accurate or reliable as technology used in evidentiary breathalyzers, they are cheaper and tend to be more specific for alcohol.

The devices keep a record of the activity on the device and the interlocked vehicle's electrical system. This record, or log, is printed out or downloaded each time the device's sensors are calibrated, commonly at 30, 60, or 90 day intervals. Authorities may require periodic review of the log. If violations are detected, then additional sanctions can be implemented.

Periodic calibration is performed using either a pressurized alcohol/gas mixture at a known alcohol concentration, or with an alcohol wet bath arrangement that contains a known alcohol solution. The costs of installation, maintenance and calibration are generally paid by the offender, and typically are about $75 per month.

The ignition interlock devices are used to eliminate the problem of repeat offenders. A California drunk driving defense lawyer will be able to provide more information about ignition interlock devices.

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