You will probably want to get to the A5.
Take Bus 5515 at the Luisenplatz in the direction of Erzhausen, until the "Am Rotböll" stop. From there you walk a bit back to the motorway, go right to the asphalted street parallel to the motorway to the service station "Gräfenhausen". Walk 2 km through the woods or try to hitch a ride from there to the service station. The station is the best in the region, for going any direction.
- This article is based on text from the German language Anarchopedia which is available under the terms of the GNU Free Documentation License.
From the central station, walk south until the first crossing and turn right and walk over the bridge. This road leads directly onto the motorway. However, it's dangerous to stop there and the traffic is quite fast. You might be able to ask people at the traffic lights.