It's funny that this is released the same day as a 56 minute overhead drone video of the Swindon magic roundabout, one of the UK's most iconic road junctions: https://youtu.be/CzQunCuQCJY?si=X1nbcxiWOCcnm8eO
An interesting effect of counting at roundabouts is that MHT/basic inertial movement models tend to work quite well, because the vehicles aren't stopping and starting, and they tend to not bunch up as much as at a red light