My point is that it will take a lot of work to train them to communicate with each other. They are not smart enough to have a scheme simply pasted in, nor are h

My point is that it will take a lot of work to train them to communicate with each other. They are not smart enough to have a scheme simply pasted in, nor are human programmers adept enough to hard-wire a carefully-trained AI to have this scheme implemented. Absent extensive retraining you'd probably just have Waymos getting confused about all sorts of edge cases in the communication scheme itself. I am not saying that it's doomed to fail - simulations can probably do most of the heavy lifting, and of course the tech itself will advance. I am saying it's a mistake to assume stuff like this is somehow a free lunch, or even "the easy part." It's unknowns about unknowns.