Most people live within a couple hours of a city though, and I think we'll see robot taxis in a majority of continents by 2035 though. The first couple cities and continents will take the longest, but after that it's just a money question, and rich people have a lot of money. The question then is: is the taxi cab consortium, which still holds a lot of power, despite Uber, in each city the in world, large enough to prevent Waymo from getting a hold, for every city in the world that Google has offices in.