https://keshavsaharia.files.wordpress.com/2011/01/traffic-op...
Things like junctions/intersections would be much better managed (we might even be able to make them free-flowing on roads where non-autonomous vehicles were banned).
In an autonomous car you can do the speed limit for the entire journey. That's 8 miles at 30mph and 92 miles at 70mph. The journey takes you 95 minutes.
In the human-driven car you're slowed to an average of 20mph in town, but on the highway you travel at 85mph because that's what everyone else does. The journey takes you 89 minutes.
Obviously the 95 minutes in the autonomous car can be a productive 95 minutes whereas driving yourself you can't do much else for those 89 minutes, which is a huge difference, but until all the cars are autonomous (or there are superfast autonomous lanes at least) then it's probably going to be quicker to drive yourself because to a human a speed limit is a guideline rather than a rule.
http://www.iam.org.uk/media-and-research/policy/our-policies...
I find it a bit amusing that we're having to invent some incredible technologies to overcome our sense of self and resulting selfishness to act like the cooperative insects we often step on without noticing.