
Consider a typical parking garage. Much of the area is used for things other than parking cars. First of all, there are the driving lanes and ramps needed so that the driver can get his/her car to a parking space. Ramps have to be wide enough for two-way traffic and lanes must be wide enough for cars to park and pass each other. In many cases, the ceiling height in a parking garage is set by building codes to accommodate pedestrians (drivers going to or from cars) rather than to accommodate vehicles.
Walkways, stairs, emergency exits, elevators and the like are all necessary for the drivers - not the cars. While we’re at it, we might as well mention that all the lighting, signs, heating, air conditioning, ventilation and signage in the parking garage are not for the cars either. Cars can’t read and they rarely complain about the temperature.
Finally, consider the width of a parking space in a parking garage. Many of us find them too narrow when we try to squeeze out of our cars. Parking space widths have to be set to so that driver and passengers can exit on both sides of a car. Parking spaces also need extra width to allow the driver to maneuver the car into and out of the parking space. This results in parking spaces being about one-third wider than is actually required by the car. Eliminating the driver (and passengers) would enable four cars to be parked in the same width as three cars with drivers.