Well, that's surprising. I've driven San Francisco as an Uber/Lyft driver and it's a nightmare. I'm really curious how it checks for side traffic when it's nose is pointed at the sky at a stop sign on a steep hill.
The evidence is easily accessible - next time I suggest you just research a little bit first instead of going straight to speculating.
Edit: The Cruise CEO kvogt says it's geofenced. That's what I thought.
In a few years our next generation of low-cost compute and sensing lands in these vehicles and our service area will be large enough that you forget there is even a geofence
As to the earlier question about intersections at steep streets, I would guess they just avoid the most difficult blocks. But they do also have superhuman vision, since they have lidar and cameras on the roof of the car (higher vantage point than a human).