One night a few weeks ago I took a Waymo ride at night. Somewhere out in an unfamiliar neighborhoood, I realized that I hadn't seen a human being for dozens of blocks. The streets were full of cars, but every single one was an empty Waymo or Zoox. I spent the rest of the ride musing about what would happen if an armed mugger jumped in front of the car at the next traffic light, and the whole thing felt a little bit less safe.