Not around here... some are 55, some are 60, some are 65, and some stretches are even 70... if you think you're in the 70 and it's really a 55 you can be charged with reckless endangerment on top of the regular speeding ticket.
Not that it's happened to me, or anyone I know for that matter, but it's just one of those things I noticed that drove me nuts... I ended up driving 55 for something near 10 MILES before finally a sign was posted showing 65... and lemme tell you, even in the granny lane, a TON of people were NOT happy with me. But how was I to know... when there wasn't a sign?
Oh and bonus points for those long stretches of construction and no signs but at the beginning of it... because down here fines DOUBLE if you're tagged in a construction zone (with workers present)... if ONE guy is down there, not even working, just standing there... double your trouble.
Hmmm... pet peeve much?