Strange. I see it working in practice 80% of the time... I’m on the road a lot, too. “Rettungsgasse” is something that regained popularity in the last years due to strong media push.
For what it's worth, foreigners driving there may not be aware of the rule. I tried as hard as I could to be a conscientous, informed road user before my first trip to Europe (studied signs, rules of the road, etc.) but still got an angry motorcycle cop whacking my mirror in France because I thought emergency vehicles would pass on the shoulder and had moved over to allow this, not in this Rettungsgasse (or the French equivalent)
What makes it worse is that the rules differ, even in EU countries. In Germany you have to make a 'Rettungsgasse' when there is a traffic jam, whereas e.g. in The Netherlands, emergency services use the 'vluchtstrook' (outermost lanes not used for traffic) in such cases.
Except where they've decided to let regular traffic use the vluchtstrook to drive on. Some roads you just need to be aware that you might need to make room for an emergency vehicle coming between the lanes.
That cop was probably angry for another reason, as Rettungsgasse are virtually unheard of in France. Emergency vehicles use the "emergency lane" at the far right of highways.
