On a highway filled to capacity by human drivers (which is about 2,200 vehicles per hour per lane), about five percent of the available road space is taken up by cars. Five percent. This is because humans are so bad at driving that we need lanes that are twice the size of our cars, and at highway speeds, we have to keep between 40 and 50 meters away from the car in front of us.
Researchers at Colombia University took a look at what would happen if we started relying on autonomous or semi-autonomous cars equipped with sensors and/or intervehicular communications systems, and the increase in efficiency is fairly incredible, simply due to the fact that cars can safely travel closer together.
.... if we all just give up driving on highways and let robots take over for us, we could effectively end highway congestion as we know it by boosting the capacity of our existing roads by a staggering 273%.The article notes that more efficient highways would be but one benefit. Roads would be safer, an enormous benefit in many ways. And "drivers" would have hands-free time to be "productive" during commutes. Work, play music, do Snapchat.