In Pennsylvania, Rte. 30 is the "Old Pennsylvania Pike," and essentially grew from the first horse trails between Philadelphia and Pittsburgh. Whereas the "New" PA Turnpike (I76) goes through the mountain, Rte. 30 goes up, over and around the mountains, with many an inn, tavern or hotel along the way. I use to drive it frequently, but it's been a few years since I've been back that way...hope it is spared the same fate as Rte 66....
Lancaster Pike! There are places that have turned into suburban hellholes, but there are still lots of cool nooks and crannies. (I live about a block off of Rt. 30.)