I get what you are saying and don't disagree about driverless cars (rather than taxis) - humans are just going to become cabbages, well too many already are but that's another topic.
Although I can probably see a situation where driverless cars wouldn't go long distances, but instead would take you to hubs, then you get on the motorway in some sort of automated pods, like tightly packed convoys on a commonly shared route. Then another driverless car is waiting for you at the other end. If you keep the cars off the motorway that then lowers the risks of delay. Although with pods I can see a scenario of leaves on line.