Changes

Take the S9 from Bern Hauptbahnhof to the end stop (Unterzollikofen), then walk over the fields eastwards to the rest area "Grauholz", it's not that far and probably pretty lovely between April and August due to the sunflower fields (been there in late September and it was still great). No controls in the S-Bahn. Take a picture from the map with your camera, might come handy. Best option fur sure! I didn't wait long for a hitch towards Zürich.