What happens when you raise speed limits on highways? Slate has some answers.
In brief: more severe crashes, but no increase in their number. And here’s something with implications for law more generally: Compliance with the law goes up. In other words, people are able (at least in the context of driving on the highway) to use their own self-interest and judgement to self-regulate. Making a law that ignores what people would do on their own makes scofflaws and weakens respect for law.