Artic Xiongmao said:
BTW, do you drive since you are 16 because you don't have any other ID? It's pretty weird for spaniards (and many others) that Americans don't have a National ID. Not a passport; that's another thing. So the driving license functions as an ID... is that right-ish?
Since it looks like no one has answered your question, I'll do so.
Yes and no. We don't have national or even state IDs, separate from driver's licenses.
Legally
(at least in my state) one can obtain a driver's
permit at age 15. This is similar to a license but with restrictions - mainly not being able to drive anywhere without a parent or guardian in the vehicle. It is used in driver's education courses as we can obtain a license on our 16th birthday, provided we pass the driver's exam. The exam is done through a state licensing center
(Department of Licensing).
Once we have a driver's license, that is our primary form of identification. It is provided by the state one resides in
(usually) and each state has a different design for the license itself.
Each license lasts 5 years before it needs to be renewed. There is no reason for this other than a steady income for the state. There are no "re-tests" or anything of the sort. Once you've earned your license, you have it for life
(barring certain circumstances).
Once you reach age 21, the license is then horizontially oriented when renewed, giving grocers and the like a quick way to ascertain the age of a person. There are counterfiters out there so there are a
lot more ways to verify the authenticity of the license than just the orientation.
Edit: Nevermind, already answered.