here's a confusing one. there are 2 types of circular road - traffic circle and roundabouts. The one at DC is called roundabouts. The one at Paris and NYC (Columbus Circle) is called traffic circle.
the difference between those two is that roundabout is smaller and slower. Most importantly - in roundabouts, the entering traffic must yield to traffic already in circle. The problem with roundabout is that the 18-wheelers, RV, or large vehicles cannot navigate through it and the problem with traffic circle is that it requires a large diameter but some roundabouts are big enough for trucks to get thru.
Traffic Circle is ineffectual and unsafe. It's old design. Roundabouts are replacing traffic circles.
About Michigan Left - plenty of it in NYC. I do it all the time. Michigan Left concept makes sense for high-volume traffic and large intersection. I'll explain why. Problem is - many intersections have 2 lanes and then as you approach closer to intersection, it splits into 3 short lanes - left lane goes left and center lane goes straight and right lane goes right. The left lane gets clogged because it's not easy to turn left at busy intersection so this creates backlog for 2-lanes. The center lane cannot go straight because of cars at left-turn lane so cars at center lane turn to right and then center but this is dangerous because of risk of accidents and road rage.
Solution? Michigan Left. You turn right and then make a left to make a U-turn and then ta-da! I love studying traffic system. That's what I want to go to grad school for.
Left-Turn especially at intersection is a nightmare for drivers. Left-Turn is one of major contributing factors to accidents and traffic jams. Michigan Left was a solution to it. Problem about it is... it's confusing to new drivers and to those who are not used to driving in high-volume traffic area.
Roundabouts is intuitive and easy but it's not always a good solution.
for correction