mikem9, let your son ride if he wants, and is capable, some of our best times were our riding vacations together.
My wife and I have rode from a young age and still do, dirt, street, and quads. Our son started riding at 3, racing at 4. MX, TT, hare scramble and flat track. He always showed good common sense and ability. He was an excellent rider by the time he was 16, you learn a lot on a race track So we had no problem getting him a CBR600F4I for his 16th birthday, then heading to Deals Gap the next day.
It depends on the person, if he's a daredevil and show off I'd be concerned to let him have a car or bike. But if he can ride well and has a good head no problem.
(There is a difference between being a fool and being proficient)