[ghaff]

I'm not sure it's universally true. I didn't but that was years ago at a private school and I still took a summer Drivers Ed class for insurance reasons.

Given that most students do get a drivers license, it wouldn't be surprising if Drivers Ed were a mandatory part of some high school curricula. Note that this is probably just the theory part in most cases and doesn't include actual on the road instruction. (Which is typically done by parents or by a company--the latter again in part for insurance price reasons.)