"an" is for arrival (Ankunft), "ab" is for departure (Abreise).
Some of the stops are very brief. That's the problem with the Romantic Road bus (or trying to do it in one day by car), all you see is a lot of a very ordinary country road. The really worthwhile part of the Romantic Road is the towns along the way, and it is difficult to schedule a trip with enough time to do them justice. I did the Romantic Road two years ago, stopping for hours at towns that I thought justified a stop, and it took me five days, from Wieskirche to Wuerzburg. A big part of the southern RR, from Wieskirche to Landsburg is not accessible by rail, as is the northern part, from Noerdlingen to about Rothenburg.
Fuessen and Rothenburg are, in my opinion, the most worthwhile stops, and they are accessible by rail, as is Noerdlingen, my next favorite town.