There any number of notorious locations or communities that appear to prey on out of town drivers by placing hidden speed traps and adhering to exact speed limits. The locals know of them and even worse the local cops smile and wave at the same locals "speeding". By contrast they seem to relish going after out of town folks who are not likely or able to dispute a speeding ticket. Some sort of warning to unknowing folks that any speed beyond the speed limit puts you at risk.