Nathan can you point be to the public discussion you had before deciding to make these blanket decisions? personally, I see no benefit to declaring a roundabout to be separate from the road it sits on. it would be suicidal to attempt a roundabout at 60 or 70 mph. and there no official consensus since presumably it is common sense to say a roundabout adopts the speed limit of the road it sits on. the only difference is that the speed limit data becomes noisier and less appealing to consumers.