Here is an informative article about the pilot program for ignition interlock devices that prevent a DWI offender from starting his vehicle without passing an on-board breathalyzer test.
Ignition interlock devices can be a win win for the offender and society as a whole. As an alternative to a license suspension, an interlock device is far preferable, because the person can actually drive, function, and keep a job that requires a car to commute or otherwise function.
And the primary goal of the criminal DWI penalty is to keep the person from re-offending. The ignition interlock program achieves that goal.
The only question in devising ignition interlock laws is to determine what the threshold for this penalty might be, and what is the duration. Many states now have an interlock requirement after a single DWI conviction, while some only with a second aggregating factor of a high BAC result on a breath test.
But whatever the underlying conditions, a sensible ignition interlock program appears to be in the works here in Minnesota.