Normally, the ignition to a car is turned to the “on” position and the car starts. With an interlock device installed, turning the ignition to the “on” position powers the device on for it to then ask the driver to perform a breath test. If the test is successful, the ignition will be allowed to start the vehicle. After about 3 to 6 minutes after driving commences, the driver will be asked to perform another test. Once this test is complete, the device then requests rolling retests every 10 to 45 minutes.