Let me rephrase what I think your argument is: "I think that we should set speed limits to somewhere around where they are now or lower, and then re-engineer o

Let me rephrase what I think your argument is: "I think that we should set speed limits to somewhere around where they are now or lower, and then re-engineer our roads to make it harder for people to speed. This is practical and will save lives, and the evidence supports this." If I'm reading you correctly, I have a number of problems with it: 1. I don't think it's in any way practical to re-engineer roads on the massive scale that would be necessary to do this. If, as asserted, the majority of people exceed the speed limits the majority of the time, you're talking about re-engineering the majority of roads. That's an enormous project compared to resetting the speed limits. 2. You're a bit light on details about what you would do to make people obey the speed limits, but you list as contributing to speeding "wide lanes, big setbacks, and homogenous environments." Leaving aside homogenous environments (are we now talking about re-engineering not only all of our roads, but also all of our cities in general?), I'm sure that making lanes narrower and setbacks smaller would in fact make people drive slower, but would it actually increase safety compared to the counterfactual of not re-engineering and increasing speed limits? I doubt it. Certainly, I don't see evidence for it. 3. Hidden in here is a question of legitimacy. Are current speed limits a result of a social consensus about the speed/safety tradeoff made by an open society? I don't think that there's any convincing evidence that they are. They appear to be a reaction to OPEC and a revenue model for local governments at least as much as they are about a democratic consensus -- and to the extent that they are about a democratic consensus, they seem to be based on one in which the democracy in general was not aware of the deleterious effects of low speed limits in terms of speed differentials. So, look, the situation right now appears to be: a. Roads designed for speed, but with artificially low speed limits leading to inflated danger. And a couple of possible future policies could be: b. Roads designed for speed, with higher speed limits leading to reduced danger compared to a. c. Roads designed for lower speed, with the same or lower speed limits leading to reduced danger compared to either a. or b. It seems like you've jumped to the conclusion that option c is the right one, but I don't know that it is, even granted that it is the safest option.