A large problem in speed limit setting is that 85th percentile is used many times for setting the speed limit and other factors are ignored or aren't weighted as heavily.

It's a very fuzzy practice, and I think as we continue towards an automated driving world, we need to be more critical of how speed limits are set.

Using the 85th percentile as a means to determine speed limits ends up with 15% of all drivers exceeding the speed limit, or worse, more drivers exceed the speed limit than those original 15% because they know consequences may be rare.

https://www.ite.org/technical-resources/topics/speed-managem...

Sometimes bad road design (e.g. lanes too wide) are to blame, but in miserable neighborhoods with no traffic enforcement at rush hour you can also end up in a situation where the majority of people on the road are simply aggressive drivers who are familiar with the road. At some point you do need to enforce the law if it isn't being respected. There is a growing subset of people in the US who not only disregard traffic law but pride themselves in a distain for it.

> If this is the case, then the speed limit is too low.

I don't disagree with you, but it's still a problem if there are drivers on that road who are driving so slowly as to be unsafe, robot or human.

IDK if it's draconian but speed cameras or simply forcing cars to have modules that report speeds at certain points and issue fines automatically should be standard by now. What's the point of having smarter cars if they can't be forced to stay below the legal speed limit.