Hitching Out
West (B28 West, A81 North and South, Herrenberg, Stuttgart, Siegen)
The Street later turning into B28 is called Rheinlandstraße. You can try to
- stop cars at the crossing with Westbahnhofstraße
- ask people at the gas station where the Herrenberger Straße meets the Rheinlandstraße
- stop cars at the bus stop about 150m west of this gas station.
The latter worked very well for me on a sunny afternoon.