The Google cars aren't really so powerful yet. They defer to humans in anything but perfect highway conditions or a completely closed area with other cars banned. Without an accurate map, they can't drive. I think they don't even change lanes independently.
> They defer to humans in anything but perfect highway conditions
What do you mean by this? The Google car can negotiate stop signs properly, for example. It's limited to good conditions in a lot of ways, but it's no train.
