"The idea that sharing rides is good has become almost axiomatic in transportation discussions. At conferences I have seen people declare that robocars are poin

"The idea that sharing rides is good has become almost axiomatic in transportation discussions. At conferences I have seen people declare that robocars are pointless if they are not shared -- ie. people who are not travelling together ride together in them. The positive of sharing is so axiomatic that public transit is seen almost as a good in and of itself, rather than a means towards real goals like energy efficiency, low cost, and higher road utilization. It has has attained this status as revealed truth because it is indeed roughly true -- more people together in a vehicle done right will indeed use less energy per person and less road space. But the "done right" is very important as it is commonly done quite wrong. As I have studied robocars, this has led me to the discovery that some of our old assumptions are wrong. In particular, more sharing is not always good, and the styles of sharing (including the vehicle sizes) of current public transportation are almost certainly not the optimum sizes, and that smaller vehicles are likely more optimal once we eliminate the need for drivers and move to a highly communicating world. I believe there are strong arguments that while shared travel is beneficial, we actually have too much of it in most transit systems, and not enough in private cars. That the 'shared' future is one of van-sized group vehicles with a mixed fleet of more personal cars with 1-4 seats." https://ideas.4brad.com/sleeper-cars-and-unexpected-efficiency-solo-transport https://ideas.4brad.com/sleeper-cars-and-unexpected-efficien...