For those who have never driven in Washington DC...take a look at Dupont Circle.
(BTW- this pic must have been taken on a Sunday morning, as 84% of the vehicles are missing!)
Yes, it has 2 circles, one inside the other, 2 lanes each, with 9 openings, 4 of which are divided lanes. To do some maneuvers, it is necessary to find the right spot to switch from the inner circle to the outer while going around, and there are several traffic lights within the circle(s), plus lights at each place one enters the circle.....and many taxis and busses, each of which KNOWS it has the right of way and does not need to pay a lot of attention to either the lights or YOU....whether driving or on foot.

The ony saving grace is that one street, (the one going from 10 o'clock to 4 o'clock) 'can' use an underpass for thru traffic...but if you get in the right-hand lane, you miss that and have to negotiate the circle.

....and though it is the most complex, it is not really the worst. I think Washington Circle and Thomas Circle are worse...with Chevy Chase circle not far behind because of the speed and multiple lanes.