In order to facilitate your access please use the Google route planer.

Coming from the north/south:
A81 in direction Singen/Stuttgart
Exit: Rottwei-Zimmern

The follow direction
Zimmern o.R.
Horgen
Niedereschach
Kappel
Obereschach

Coming from the west:
A 5 Karlsruhe – Basel
Exit Freiburg
Donaueschingen – Villingen
Obereschach