In a very local sense, this is true. In terms of the traffic system, this can create a systemic problem if the stoppage causes a traffic jam that creates problems for emergency vehicles.

Thus it is a _different_ failure mode.

If someone stops in the middle of traffic because they’re lost, their GPS went out, or they realized that they’re unsafe to drive, we don’t celebrate that as the driver entering a fail-safe mode. We call that “bad judgment” and give them a ticket.

If it precipitates a larger problem where lives are lost, they may be in considerable legal or financial trouble.

I don’t see why we should treat Waymo any differently.

You don’t need to wait for a city blackout to actually test this kind of scenario.

The thing still has cameras. And LIDAR. It should be fully capable of pulling over on its own safely. Why would not having a traffic light prevent that?

Humans are expected to negotiate this. The robots should be too. That’s part of driving. If the lights fail, the law tells you what you’re supposed to do. And it is not stop the intersection.