Batteries?
And you were doing so well until the last bit. If you imagine the world's fleet of autonomous cabs is going to be powered by pure electrics, you're going to need some breakthrough in energy storage density, of which there's currently no sign (and is unlikely to be electrochemical in nature, since that's already close to the limits imposed by materials science).
A typical London 'black cab' does 200 miles a day (private hire vehicles do rather more). Your Tesla may have a quoted range of 200 miles, but that's at highway cruising speeds, not in start-stop city traffic.
Biting the hand that feeds IT
