A: 81 is a bit shorter and also much prettier because you see the mountains most of the way. You won't see much while you're still in Alabama, but once you get into Georgia, you'll start seeing some beautiful views. Take 59 to 24 to 75 to 40 to 81. 85 may look on the map as if it's better, but it's incredibly ugly and boring. I've done both routes many times (New England to AL) and now I stick to 81. You also avoid the bad cities for traffic (Atlanta, Richmond, DC, Baltimore).
