Durham - Don't loosen your billboard restrictions. I hear Memphis is a beautiful city, but you'd never know it from the freeway. And those animated video billboards that our friends at Fairway want to bring to town? Hell, one of the billboards i passed was showing full motion video of dog racing in an ad for a greyhound track. Try keeping your eyes off that while your driving.
Speeding - Holy Cow! The speed limit on I-40 is 70 mph almost the whole length of the road, excepting some urban areas. From Albuquerque to the Mississippi River, i set the cruise at 70, and sat in with the flow of traffic. I don't think half a dozen cars passed me the whole 750 or so miles, and certainly all of the truckers were at the speed limit as well. As soon as we hit Memphis, aggressive driving became the norm. Even with a more visible police presence. Being passed by cars doing 85 or better, and weaving through multiple lanes of traffic seems to be an east of the river phenomenon. We also saw our only accident on the trip in western NC - someone had plowed into the car ahead of them at a pretty high rate of speed.
Barbecue - This wasn't a food excursion, and we didn't have too many opportunities to appreciate the regional barbecue variations along the way. But it's hard to imagine anyone does it any better than the Pig Out Palace in Henryetta OK. Even the sweet potatoes were delicious, and i am not a fan of the yam. Worth seeking out if you're passing through Oklahoma. If they only served beer. . .