An interlock device is a device used in vehicles that tests the driver's blood alcohol concentration and prevents the vehicle from starting if it detects alcohol above a certain limit. Full definition
After you have been arrested for a DWI offense, you may be required to have an alcohol ignition interlock device installed on your vehicle as a condition of your bond (before your case is heard in court.) (versustexas.com)
Since this is her first DUI, under the new ignition interlock laws, she will need an ignition interlock device installed in her car. (1statlantaduischool.com)
Researchers at the University of Michigan Injury Center and the University of Michigan Transportation Research Institute studied the impact of installing these alcohol ignition interlock devices in all newly purchased vehicles over a 15 - year period; their estimates of injury prevention and cost savings are significant. (sciencedaily.com)