Google seems to be focused on automating commuting, but really isn't the goal to eliminate accidents due to all forms of human error? That means driving while drunk, texting, tired, etc.
The technology is getting better rapidly, but until someone can legally flop wasted into their back seat, at 4 AM, shout "Take me home!" and drunk text their ex-girlfriend like they currently can in a taxi, it's not going to get much traction.
So I'd say we're less than 10 years out from a tech perspective, and n years out from a legal one.