The so-called rotaries are an example of Yankee idiocracy, not to be confused with Rebel ingenuity, infecting our cherished Dixieland.
I first encountered these traffic devices while serving in the U.S. Navy, stationed in New England. We sailors had a special name for them: Balley Circuits; with slang expression of the "guts" one must demonstrate to take the right of way.
Barely missed a collision in the rotary, today, at the upper end of Laney Walker Boulevard in Augusta. A driver came barreling in so fast I never saw her coming as I entered the rotary. Of course, she thought that I was the bad guy.
It's like four-way stops, where you never know what the other person will do; and, it's dangerous.