There are several ways to get a speeding ticket when you BELIEVE you are legal
one is the old "Hide the low MPH sign behid a tree or bush" trick (Works for stop signs and no parking signs too) I have been the victim of one of those (parking) Trust me the only way to see the no parking sign was to stand with your toes touching the post and look nearly straight up. (It was behind a canopy) they moved it DOWN about a foot after I complained so it could be seen.
Suddenly dropping from 55 mph to say 35 mph also gets a lot of folks.
I once got a ticket for disregarding a "No Turn On Red" sign, never mind that county and yet to erect the sign (took 'me 3 weeks after the judge dismissed)
I once got a ticket for failure to signal a turn... Problem was.. I DID NOT TURN. (Same officer as the last ticket).
And we have all heard of how to make a radar read 90 when you were going 40.
(I think it was 60 minutes, Dilbert's favorite TV show, that showed that one).
So simply obeying the speed limit will not always do the job.
IF it is a town AAA underlines in red... Simply avoid it. IF enough people avoid it, when the town father see all that lovely tourist tax money passing them by,,, They will fix the problem, as has happened here.
But then I grew up in a town which had a Justice of the Peace who resigned when he heard the auditors were coming a-calling.... And for good reason too.. Last I knew (I suspect now he is deceased, Cause: Old age) but last I knew he was still working for the government,, cleaning toilets and refilling tissue dispensers and mopping floors and emptying trash cans. (School janitor)