Original title: When driving on the wrong side of the road is the right way to speed up traffic

There are a few Diverging Diamond intersections around here and they seem to all work rather well from a vehicle perspective. I can't speak about the pedestrian side of that equation, as I've never been on foot.

Compares to a roundabout placed over a highway, it uses 1 bridge instead of two, but otherwise I don't know which flows best.