You missed the most disruptive potential change that will decrease the number of cars needed: driverless cars. These cars can make car sharing so much easier an

You missed the most disruptive potential change that will decrease the number of cars needed: driverless cars. These cars can make car sharing so much easier and more efficient that the numbers of cars needed for getting people around will shrink dramatically. Imagine all the traffic during the work hours will be taken care of by the cars used to sitting in the parking for a whole 8 hours long. And all the house car sitting in the garage during the traffic hours taking care of the people going to and off work. I wouldn't be surprised if the total number of cars shrink to one third without anyone feel any inconvenient.