text: Yes, I was meaning that the footpath is unlikely to cross the dual carriageway on the level. You're right to point out that unfortunately many do, though I think that it's probably better with more modern roads, which I believe that this one of.
  
  Nevertheless, if this really does cross on the level then there'd need to be some shared nodes between the carriageways and the footpath. If the path got severed then that'd need to be reflected in the map data, and if non-motorised transport really has been considered and a bridge was created for the footpath or by the road then that'd need to be reflected in the OSM data too.