Hitchhiker

Best spot for going south, but it's very hard to reach by foot. Ask the locals to drop you off at "Offenburger Ei".

There's a big billboard near the exit where you can stand in the shade after 13:00 (once the sun has moved).

The parking lot is a barren wasteland for trucks only. The access road has a narrow side strip where cars can stop, but there's only industrial areas and tiny villages nearby, so if you travel on sunday like me, there are no cars at all. I tried standing behind the guard rail of the deceleration lane, but gave up after 2 hours and walked to the train station.