These are a great source of traffic accidents and dangerous as heck.
They may be cheap but they’re not effective at traffic control, or safety.
With typical Teutonic thoroughness, Germans actually learn how to drive before they are permitted to get behind the wheel. The problem in America is not the circles, its the ditzes.
They used to have a stop light system there ~ and almost every time you came through there you got stopped. That intersection took an average of 5 minutes to navigate.
With the circle in place it takes almost no time at all.
The problem at this point is that at different times of the day, 24/7, the principal thoroughfare changes many times. This has nothing to do with an urban rush hour ~ more like fishermen, tourists, locals doing shopping, and mysterious employees working in mysterious operations, somewhere, in buildings with fake signs on them.
I guess the traffic flow patterns were simply beyond the ability of computer operated stoplights to keep up with.
A traffic circle has no trouble decoding the opportunities, and so it works.
I'd guess most everybody around there hates it.