>Then again, cars could all come with roll cages and five-point harnesses, and they don't, so there's some limit to safety equipment. No roll cages historicall

>Then again, cars could all come with roll cages and five-point harnesses, and they don't, so there's some limit to safety equipment. No roll cages historically was the result of no federal safety belt law. Roll cages are great until an un-belted occupant has their head hit the cage. "Second collision." https://en.wikipedia.org/wiki/Second_impact_(safety) https://en.wikipedia.org/wiki/Second_impact_(safety) At this point New Hampshire is the last remaining holdout on state safety belt laws. Live free or die (in a car crash). Even then, you still have the issue of noncompliance. Automakers don't want to end up on 60 Minutes in an episode about how their "safer car" kills some people, because some of those people were un-belted in a crash. Numbers are all over the place for people not wearing their seat belt, but it's somewhere in the neighborhood of 1 in 10.