There’s an upsurge of “roundabouts” (we used to call them “traffic circles” here)in northern Virginia. It’s part of a move called “traffic calming” to avoid the starts and stops and traffic surges of regular traffic lights.
Also they may be cheaper in the long run—since there are no traffic lights to maintain.
Where Route 50 meets Route 15 (a major N/S road going for NC up into NY state) TWO roundabouts are used, and, so far so good (as far as I know). Used to be a major intersection of two heavily traveled roads, where you’d always want to time the light right... now you don’t have to slow down so much...
I know huge traffic circles (with 5 or more roads coming together) can be dangerous, but roundabouts as an alternative to a typical traffic light, may well be a good thing.
There are only two rotaries I ever recall seeing outside of Massachusetts, one in Westchester County, NY and one in southern New Jersey, near Atlantic City. I’ve spent a lot of time in Eastern Virginia, btw.