For decades the road between Asheville and Jonesborough, Tenn., was a hard one. It was a pretty route, skirting farmland and winding up and down wooded mountains, but it was two lanes much of the way, and it wasn’t a road drivers could take in a hurry. Even as recently as the turn of the millennium, Interstate-26 only went so far into Madison County. And then the highway ended, and travelers were plunged into rural switchbacks — roads that followed the natural lines of the mountains rather than blasting through them. See the full article.