No discussion about roundabouts can be complete without a mention of the (mostly) Dutch "turbo roundabout", where the lane you take going into a multi-lane roundabout depends on where you want to exit, and you can't / are not allowed to switch lanes while on it:
https://wiki.openstreetmap.org/wiki/Tag:roundabout%3Dturbo
https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts
https://www.arcadis.com/en-us/knowledge-hub/blog/united-stat...