[Dan Petrovic]

Hmm... this is interesting.

I think this sort of thing is at the discretion of the parents. If they feel the kid shouldn't drive due to poor grades, then either don't let them get their license or don't let them drive.

The state has no right to be telling people that they can't drive due to poor grades (well, technically they do, but they shouldn't!). They don't know what's going on in that family. Any sort of family problems can cause grades to drop, the kid could be a fine student but once there's serious trouble in the family that distracts that kid from their schoolwork, things can change. It could be loss or severe illness of a close family member, a divorce, parents losing their jobs, and other extremely stressful situations.

On the contrary, if they are failing because they don't care, then simply taking their license away for a year or two wont change anything.