These types of towns use dirty tactics to catch people, like going from 75mph to 45mph without warning, often at the bottom of a hill or without enough time to properly slow down without hitting your brakes.
There are many states without absolute speed limits. This means a speeding ticket is really an ‘unsafe speed’ ticket, and you can get out of it if you can argue the speed was safe for the road conditions, even if you fully admit to exceeding the posted limit. It’s also what allows cops to issue warnings instead of citations.
These towns basically exist to create situations where they can write citations for things that could easily be beaten in court. Their hope is that the people won’t return to the town to fight it.