An alcohol ignition interlock device (IID) is a breath-test device that is connected to a vehicle’s ignition. A vehicle with an IID installed will not start unless the driver blows into the interlock and has a blood alcohol concentration (BAC) below a limit set by the court—usually .02 BAC. IIDs must be installed by a certified technician approved by the state’s department of motor vehicles (DMV). The IID will collect data (engine starts and stops, breath test results, and tampering attempts) and report it to the monitoring company, which will report it to the court.

IIDs reduce repeat offenses for DUI/DWI by approximately 70% when installed. Laws vary from state to state and courts have significant discretion, but a judge may order a person convicted of a first DUI/DWI offense to install an IID and will order a person convicted of a second or third DUI/DWI to install an IID. Courts will often order an IID installed on the defendant’s vehicle as a condition of bond (to be released from jail) and of probation (following jail or prison time, or in lieu of any or more jail or prison time). The court may order the defendant’s IID to remain on the vehicle for 1-3 years or more.

Despite these laws and programs, only about one-fifth of those arrested for DUI/DWI have an IID installed.

In Oregon, an alcohol ignition interlock device (IID) is required for all individuals convicted of driving under the influence of intoxicants (DUII). After a first DUII offense, the court may order the installation of an IID during the period of license suspension and for a time after driving privileges are restored. For repeat offenders, the installation of an IID is mandatory. The required period for maintaining the IID in the vehicle can vary, but typically it is for one year after the suspension period ends for a first offense, and longer for subsequent offenses. The device must be installed by a state-approved technician, and the data collected by the IID, such as breath test results and any attempts to tamper with the device, is reported to the monitoring company and potentially to the court. The goal of the IID program is to reduce the likelihood of repeat DUII offenses by ensuring that drivers do not operate vehicles while impaired.