I don't know that. You asked for numbers on how many supervisors per car are needed (I bet it's around 1:100, probably less) and how often they intervene (a few times a day at most? Otherwise you'd read articles about cars being stuck all the time). If you knew the actual numbers, you still wouldn't know HOW it works. The post does shed light on the actual workflow and gives you important details that you wouldn't glean from the numbers alone, e.g. that the car is always the one in control.