An anonymous reader writes: An opinion piece at The Conversation questions the common belief that autonomous vehicles will easily solve a host of problems with road-based travel, including safety and traffic. "Assuming autonomous vehicles were one meter apart and traveling at 100 kilometers per hour (an aim that has been stated as the ultimate hope) this would mean around 25,000 people per hour could be taken down a freeway lane. While impressive, this movement capacity is only half that of a train. But getting to this capacity means 100% of vehicles are under control of a guidance system, with none under independent control. As soon as one car does this, the whole system would slow down considerably, as is seen on freeways now." The writer argues that a better role for autonomous cars might be to take passengers to and from hubs for public transportation.