Historically, smaller towns have used too-slow speed limits (coupled with strict enforcement on out-of-towners) as revenue producers. Lots of stories about places like Palmetto, Florida, or Selma, Texas. (SOB doesn't necessarily mean "Selma Official Bear".)
A study was done by the Society of Automotive Engineers a number of years back on the relationships between speed and safety. On Interstates, a driver is safest if he drives about 7% to 8% faster than median traffic speed. That's actual driving speed, not related to speed limits. You're safer if you drive faster than most other drivers, even if EVERYBODY is speeding. There is a reason.
On Interstates, traffic tends to run in clumps. If you're running faster than a clump, you pass one car at a time, with you being the decision maker. If you're driving within the clump, you're relying on all those other drivers to always make correct judgements of time/speed/distance. If you're driving below the speed of the clump, you're also relying on all of those other drivers making correct decisions about lane changes and suchlike as they pass you.
So, you get past a clump and you're running solo, all alone, for a fairly long period of time--and that's as safe as it gets.
Traffic engineers have told me that the overall safest condition in a city is to set a speed limit which is 85% of the median speed of all drivers in that reach of street. Unfortunately, local politics often sets limits too low, both from erroneous perceived safety and for revenue generation.
I have no objection to speed limits in school zones, but I'd like to see a change to include "When Children Are Present". Their presence is commonly only some fifteen minutes to thirty minutes out of a two- or three-hour control period.
As far as raw speed and speed limits, I'm one who only considers road conditions and my tires--and, of course, the cops. But I've probably got more time above 100 mph than almost anybody on this board, from years of sports car racing. Even a little time up around 200, and a fair amount in the 130 to 150 range. I've never had an off-track whoopee. But I'm generally at or below the speed limit in towns, with my head like a little hootie owl, always turning and looking for that guy who's out to get me.
And old age has me deliberately slowing down to where "I'm down there with the incompetent."
Art
"Life begins at 180"