Speaking primarily about seat belt laws... I don't think that it was a matter of "do gooders".I disagree with force used in laws like the ones I mention becase do gooders think that they are needed to save lives .
At least in my state, mandatory seat belt laws were "passed" by extortion. The Feds said to either enact the law or face a reduction in highway funding.
I'd imagine that it's a similar case for most states.
We were, however, somehow able to get the "mandatory helmet" law overturned.