If your son is missing stop signs, you simply cannot turn over the keys to him. Missing a stop sign can mean someone dies. If it is someone else’s loved one, your son will carry that burden for the rest of his life. If it’s your son, you will.
You’re the dad. You have to spend enough time driving with him to know he will be safe. No exceptions.
I’m sorry for the bluntness. I’ve seen too much.