Remember that the passenger cars are not the only thing that can scale; if you can automate the mapping and data preparation part of the process sufficiently, y

Remember that the passenger cars are not the only thing that can scale; if you can automate the mapping and data preparation part of the process sufficiently, you may even be able to reduce it to mostly a matter of driving a few sensor cars around for a few weeks; maybe even cars that are adapted versions of your normal taxi vehicles, but with a human driver behind the wheel while you are mapping. I would imagine that while Waymo's mapping efforts have been very human effort-intensive so far, they will be looking at developing this automatic map-making capability as a high priority for rolling out new cities. Scaling the rate of expansion is then mostly a matter of throwing hardware and compute at the problem.