On the road Americans eat at chain restaurants because they are predictable. No surprises, but at least no unpleasant surprises. My short list of acceptable chains: Arby's (sandwiches), Burger King (burgers), Cracker Barrel (southern style real (non-fast) food for breakfast, lunch, and dinner), Red Lobster (seafood), Olive Garden (Italian), KFC (chicken).
If you want something classier find a webpage for your target city. Look for a link to restaurant reviews by the major local paper.