I did not know that at all about SD.
So you can get drivers licenses at 14? Or do you get permits at 14?
Same here with the farmers. I don't know if there even is a minimum age for driving a tractor on the road.
We get our permit at 14, and we have to drive with a parent / guardian for 6 months (if we took drivers-ed, or 1 year if we did not take drivers-ed). At 16, we get our Restricted License, which we can drive wherever we want, without a parent/guardian, but cannot drive after 10pm. Then at 18, we get our Unrestricted (under 21) license, where we can drive at anytime.