No, I don't think I have driven in the Atlanta area. But I have driven in Chicago, Denver, St. Louis, Baltimore, etc. etc. I know exactly what you're talking about.
Heck there are times here in Iowa where you would be impeding traffic on the interstate if you are not doing at least 10 over.
(I'm a salesman so I have a lot of windshield time. Like VC, I fairly regularly have chats with the Highway Patrol, County Sheriffs, and the occasional city cop. I get very few tickets fortunately.)
With that said, it is really strange. Atlantans are such nice people when they are not behind a wheel.