Double lanes are still orders of magnitude less efficient than trains. In some dense European cities there's physically not enough road surface to put every tr

Double lanes are still orders of magnitude less efficient than trains. In some dense European cities there's physically not enough road surface to put every traveller in a car, self-driving or not. https://en.m.wikipedia.org/wiki/Route_capacity#/media/File%3APassenger_Capacity_of_different_Transport_Modes.png https://en.m.wikipedia.org/wiki/Route_capacity#/media/File%3...