I've definitely seen footage of Jag's using a road. I think!
Many stretches of the autobahns in “West” Germany were designated for runways if needed. They were designed so that the central reservations could easily be removed. The Jag video (and you did see it), was taken on a German Autobahn near Laarbruch I believe, but I could be wrong. RAF Bruggen did not have any Autobahns close by in those days. Now they have one from MG to Roermond that would be parallel to Bruggen’s runway, perfect for those Ops