I'd take it one step further. Surreptitiously drugging up the driver to determine when the driver declines to get behind the wheel. If that point is not reached below the DUI levels, yank the license. Too many complaints and the driver is examined thoroughly. If bad habits have crept in, restrictions would apply.
Good drivers know when to quit.
Bad drivers don't. We've got to exercise some preventive measures now. Until we do, I'm still looking for an affordable Hummer. Home Opinion Poll Profound insights into the burning questions of our time.