The vast majority of speed limits are set by political process rather than following the design limits, or even the M-85 rule (85% of traffic travels at or below this speed).
I don’t know where you live, but in my city, the powers that be have LOWERED the speed limits on many key thoroughfares. Streets that have been travelled for literally generations at 30 mph have suddenly been re-regulated to 25 mph.
Do the math, FRiend.
My town here in NJ just put up a bunch of “no turn on red signs” all over the place; while I understand that at some busy intersections with a lot of foot traffic, many others are in bizarre, quiet places.
Remember the whole uproar when NYC cops stopped writing tickets because of DeBlasio’s community activism against the NYPD? I hope people paid attention, and realized how much the city was dependent on that revenue.
In the NYC metro area it is more about parking tickets than speeding, because an actual traffic stop in an urban area can precipitate a hail of gunfire.