Exactly this. This isn't some kind of roving solitary confinement, it's a safe vehicle for human workers to travel through automated automated-robot-only areas.

An Amazon exec posted about it on Twitter saying that they scrapped this idea and replaced it with a vest with a sensor on it that causes automated robots in the vicinity to stop moving (creating a safe zone around the worker).

I hate Amazon more than most, but this invention is kinda cool, and also probably not going to get used.