Each morning in the U.S. approximately 300,000 drivers must blow into a cell-phone sized device connected to the car's ignition. If the device detects a BAC above the programmed limit (typically calibrated at .02%), The engine will not start. The device, officially known as an Ignition Interlock Device (or IID or BAIID), is an attempt at using technology to overcome human nature.
Some opponents of drunk driving argue that convicted offenders should not be permitted to drive at all. Unfortunately, that stance ignores a sad reality about recidivist offenders – approximately three quarters of convicted drunk drivers continue to drive with a suspended license. Accordingly, activists now argue that the IID – by requiring a sober driver – is a more realistic approach.
If you're fortunate (or unfortunate) enough to be permitted to drive with an IID, you'll find the proposition to be costly (unless you qualify for a low-income alternative in your state). You will be responsible for installation, monthly lease payments, service fees and removal. And you will have to provide proof to the court: typically a vehicle identification number (VIN), proof of installation and a certificate of installation or a copy of the lease agreement.
According to MADD, approximately 20% of those arrested for drunk driving (and about 28% of those convicted for drunk driving) are currently installing interlocks. Below are state rules for IIDs.