I have a real good friend up here that went to visit his cousin in Tulsa last year, when he came back he told about driving around Tulsa, said when they'd pull up to a stop light, Larry said he'd throw up his hand to the car next to em, said people looked at him like he was nuts and then his cousin told him he'd better stop wavin at people before he waved at the wrong car and they got shot.
Needless to say, Larry felt Tulsa wasn't a very friendly city. course Larry's lived over here in Arkansas all his life and probably waved at every cars he's met on the gravel road for the last 50 years.
that's the way we were raised several years back, you waved at people cause people were generally friendly, just in the past several years has it become a bad thing.
(still a good thing over here, you wave weather you know them or not and chances are they'll wave back, cause they don't want'a take a chance they might know ya and not wave)