On Saturday I mapped the service deck road on the roof of the Touchwood Shopping Mall in Solihull where delivery trucks arrive and ship goods down by lift to the shops below. You can see it here osm.org/?lat=52.41281&lon=-1.77833&zoom=16&layers=B000FTF It involved some delicate negotiations with the security guard to persuade him that I wasn't going to have an accident in a traffic-free zone and sue the arse off his masters (It was traffic-free because of the icy weather although the ice had completely disappeared).

Is this a first or are there other examples of roof-top roads?

Brian