Comments about ‘Ex-Layton teacher accused of sex with student’

So, here's my dilemma. Why do we say that 16 and 17 year old kids can't make the determination whether or not to have sex no matter how much older their partner is, yet, we allow these same kids to operate a couple of thousand pounds of metal full of flammable explosive (gasoline) up and down our roads with some of our other children? If I can trust my son or daughter to operate one of the deadliest items they will ever encounter, can't I also trust them to make a decision about whether or not they will or won't become sexually active and with whom they will do it with? This whole "position of authority" thing just doesn't fly with me.