It is now considered that multi-lane roundabouts (which permit lane changing in the roundabout) are a bad idea because they have too many collision points. Turb

It is now considered that multi-lane roundabouts (which permit lane changing in the roundabout) are a bad idea because they have too many collision points. Turbo-roundabout is a much better alternative: https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts