This is a layperson’s view. …. but to me, traffic flow resembles that of a fluid, the flow of which is studied by something called “fluid mechanics” ( I don’t know if I am right)…and I see that in any situation where a volume of fluid has to go through a narrow area, and change direction, a swirl is what happens naturally, as the best solution for the fluid to emerge, moving in a different direction.
Then why have all the traffic “circles” in Bangalore been destroyed and why have the far-more-collision-prone (try two streams of fluids crossing each other) intersection model?
This was inspired by the traffic flowing around the circle at the Ashoka pillar in Jayanagar… I feel curves work for traffic flow, straight-line intersections don’t.