Just don’t take one if another one is operating nearby. If they see another waymo, having passed the insecure emotional Turing test, they get self-conscious and wander the neighborhood backstreets until the other one has dropped off its passengers.
(Just experienced this multiple times in Phoenix. It’s impressive at navigating and braking, but not rational planning or flocking.)
This has not been my experience at all and I take Waymos pretty frequently, especially at popular areas like concerts or airports you'll see a bunch of them dropping off/picking up people without issues.