Well, let's get back to Clarksville for a moment, then...sort of. When I lived in Clarksville I was right off of Highway 41 ALT, and as often as not, when I drove from Clarksville up to Chicago to visit my college buddies, I would take Highway 41* (which heads up north through Kentucky and western Indiana before going to Chicago then into Wisconsin as well). Rambling Man is, of course, a key feature of any good road tripping mix, and I always liked that I was driving on the highway that the old boy was born on. Fortunately, I was not in the backseat of a Greyhound bus.
*Other times I took I-24 west through Paducah and Metropolis, then I-57 up north through Illinois. I liked Highway 41 better. It was just about exactly the same amount of time, and I liked the "backroads" of Indiana better than the interstate in Illinois. Not that Highway 41 was really a backroad, but you catch my drift.