> On one hand, speeding alone when done by a mature highly-attentive driver isn't really dangerous no matter the limit, because the driver has enough expertise to know what his personal limit ought to be. The residual risk is more from immature drivers, the mistakes of other cars, cyclists, and pedestrians.

The problem is the vast majority of drivers overestimate their skills and underestimate the risks. Many people are also emotional drivers and will drive faster when angry or stressed. A great combo.

> I settle for a middle position, which is that the speed limit should be no less than 35 mph on most streets, with heavy mandated use of automated collision avoidance systems.

So what are you going to do about all the millions of existing cars out there without collision avoidance systems?

Given all this, the easiest solution is for people to drive the speed limit, especially in urban areas with pedestrians and bicyclists.

If you really want to gas it, go to a racetrack or buy a motorcycle and donate your brain.