A 10 person vehicle necessarily needs to be larger and have a more powerful drivetrain so it would be less efficient in the dead miles it has to drive to get around and pick people up. So I don't see that 10-person vehicles would become the norm. I would actually see it going the other way, and that 2 person vehicles the size of a smart would actually become the norm. Most people currently have excess seating capacity (5) for the few occasions when they need it. But with driverless cars, you don't need that, because you can spread the load over several cars. Why drive a 10 capacity car around for the odd case where 10 people need to go to the one location, rather than 5 2 person cars that can assemble when needed to cart 10 people on the same trip.