There are other concerns as well, such as individual freedom. If you randomly chose half the population and stuck them in padded rooms, you'd also reduce the number of car accidents. There's value in allowing people to make stupid decisions. What the OP is advocating is how to prevent yourself from making stupid decisions in situations where you're allowed to.

Then again, maybe that's what this debate is about... whether we should help people individually be rational, or give incentives at a group level for being rational. But it seems to me that restricting the use of cars doesn't make people rational, it just takes away the freedom to make stupid choices.