| Ignition interlock devices are systems utilized in most | | | | the vehicle, ignition interlock devices will also |
| states, as well as Canada, as an alternative sentencing | | | | occasionally require random tests as the car is being |
| measure for DUI offenders. Ignition interlock devices | | | | driven. These "rolling re-tests" are a precautionary |
| are designed similar to the preliminary screening | | | | measure to ensure that the DUI offender does not |
| breathalyzer devices utilized in law enforcement, with | | | | allow a surrogate to breathe into the tube in order to |
| the notable difference that they are affixed to the | | | | start their car while he or she is intoxicated. If no |
| transmission of a DUI offender's vehicle. The device | | | | breath sample is provided, or if the sample exceeds |
| requires the driver to breathe into a tube, after which | | | | acceptable blood alcohol levels, the device will log the |
| the car can be started, provided the driver's blood | | | | event and sound an alarm until the vehicle's ignition is |
| alcohol level has proved to be below a pre-set limit. In | | | | turned off. Ignition interlock violations will likely result in |
| Massachusetts, that limit is .02. | | | | the suspension of the interlock user's driver's license. |
| In addition to requiring a breath sample in order to start | | | | |