Comment by Zigurd

Not every edge case, but enough that the vehicle can correctly determine it doesn't know how to proceed and must ask a human to choose from among a menu of choices. This is how Waymo described how supervision works. Nobody actually drives the vehicle remotely. They just make a decision the on-board intelligence has decided it can't make.

One good bet based on Waymo's decision to expand is that the amount of supervision each robotaxi needs keeps going down, so supervision is not tightly coupled to fleet size.