I'm a nerd for museums. If it's full of stuffed junk, old junk, or interesting junk, I'm all over it. Today, I was thinking of all the times as a child I asked my parents or an adult a question like, "Why should I eat my vegetables?" and they would answer, "Because I said so" or give some non-applicable answer. (Little kids have a hard time believing anything that they can't see or remember directly, unless it's urban legends. Children have a genius for remembering blatant lies.)
So when I grow up, I'm going to found "The Why Museum." It'll be full of pictures and other hands-on things that explain the "why" to every rule, like seatbelts and vegetables. Sure, it might be scarring for a little kid to see the mangled body of someone who didn't wear their seatbelt, but it'll be more effective in persuading them to buckle up than a vague story a parent whipped out to stop the arguing.
It wouldn't just be for teeny tiny kids, either. Teenagers would be definitely welcome to see what happens to the morons who text and drive, the morons who drink and drive, and the unfortunate souls who mess around with their significant other and get in trouble.
I'm hoping it'll be like the Holocaust Museum; people will come out shell-shocked, but at the same time they'll want to change the future based on what they've seen.