something that might not be clear to the not so american among us.
Part of our federal system here is state control over driving. Each state has its own driving regulations (i.e. age, rules of the road, test, style of license, etc.). If I remember right, you can get somewhere around 70 points in UT, but only 12 in MD. But each issues a different number of points. And some don't issue points. MD, for example, allows a learners permit at 15y9m, but requires those that want a license at 16-18 to attend a drivers ed course, which isn't offered through the schools (but, the course are heavily regulated by the state). For the first year of driving, there is a provisional license that allows driving between 5am-12am. That can be exchanged for a full license afterone year. I can't remember if the provisional is issued to those getting their first license when over 18 (I doubt it). Each state can issue licenses at a different age. But, each state honors the decision of the other states. So, if I can drive at 14 in Montana and go to MD, I can still drive, even though I would not be allowed to if I was a MD resident. Make sense?
The important thing to remember in all this is that the US is built on a strong federal foundation, so the states (which until the Constitution was ratified were independent countries) retain a significant amount of power. It took the Civil War (War of Northern Aggression/Southern Independence for those in the southern US) for the federal government to secure its authority over the states in many matters. Indeed, until the 14th amendment, the Bill of Rights did not apply to the states. Of course many had the same rights in their state constitutions, but that's another matter. Anyway, now I'm off topic.