Getting there

A8 München – Stuttgart – A81 Singen:
Exit Bad Dürrheim or Geisingen > direction Donaueschingen
exit Donaueschingen Nord > direction Furtwangen
Wolterdingen > Hammereisenbach > Urach (Richtung B500)

A5 Frankfurt – Karlsruhe – Basel:
Exit Freiburg Nord > Glottertal > St.Peter > St.Märgen,
direction Furtwangen B500 > direction Donaueschingen > Urach

Alternatively, shorter route:
A5 Frankfurt – Karlsruhe – Basel:
Exit Freiburg center > through Freiburg always direktion Donaueschingen B31,
at Hinterzarten >  direction Triberg (Furtwangen) B500 > direction Donaueschingen > Urach

Even shorter: Ca. 6 km to Freiburg > Buchenbach (Wagensteig), to Buchenbach, right direction Thurner (relatively narrow street) > left direction Triberg (Furtwangen) > Donaueschingen > Urach