Ah, in a 3rd party system, where the service is constantly having cars in motion you mean? There has been talk of Tesla's having this as a future feature, where the owner is in a stationary location like at work or home,and the car is out shuttling other people around earning the owner revenue. I wonder how such a model could increase traffic since it would assume no cars are at rest in garages, parking decks, etc. It could be more efficient if it was all in sync though