My parents made me wait until I was sixteen, but many of my cousins that lived in the country got their DLs at 14, and started driving at 12 or 13. Course, most of them had started driving tractors at 10 or 11. Come to think of it, one of my cousins did wreck four cars before he was twenty, so maybe it wasn't a great idea.
My GF’s kid has been driving around the farm since he was 10. He’s 13 now and takes the jeep out for a spin on family land every Sunday after lunch.