I suppose that's a reasonable enough question which although I can't personally answer at the moment, I'm sure someone can (Like Spike maybe, ah..Spike?) In the state I live (in a different country to the U.S.A so I guess this is just another example of what you are refering to) 3 years after a driving offense (such as a minor speeding or traffic violation) that particular transgression gets wiped and demerit points against your drivers licence are restored. Of course there are some (more serious) transgressions that "stick" so to speak, and I would dare say some transgressions here might fall into that basket, but perhaps not all.