[wsy]

The situation becomes clearer if you take a look at the traffic today with a human operator in each car. Also in this model, engineering and human failures happen. Engines break, tires get punctured, brakes fail, and humans make errors. We still accept the deaths and injuries caused by car traffic, and don't prohibit cars.

So it is more than sufficient if you can show that AVs - on average - cause less harm than human-operated vehicles.

To your specific question: when the AV loses connection, it would do the same as a human driver when a tire is punctured: turn on warning lights, slow down, and stop at the roadside. Like in other car failure situations, that might cause an accident in some cases. However, that is fine, as long as it is rare enough.

(disclaimer: I'm not working in AV tech, I don't know if current AV technology handles this case as imagined)

[nradov]

That doesn't make the situation any clearer. Coping with mechanical failures isn't the primary concern. The issue is how to handle edge cases where the AV software is unable to decide on any course of action.