text: Hello NunoCaldeira,
  
  Please take a look at
  https://wiki.openstreetmap.org/wiki/Tag:junction%3Droundabout
  and search for the word "shortcut". The wiki says clearly that you have to map such lanes as separate shortcuts.
  
  When you enter the roundabout with a car, you need to know early which lane you have to use, because you can't change the lane while you are in the roundabout because the lane marker are forbidding it.
  