law may disallow crossing a dual carriage way, nontheless if people cross it at that certain route i don't see a reason  to not map it. As for tram crossings, they do hold a big value, because you know that you do cross one on your way, coz you know ahead of time that you gotta yeld for instance. But like i said, aanyone can map any tags. Only some people do delete em i gues. 