>"Nobody has managed to explain me how self driving cars reduces congestion. It is space that is the limiting factor, and I do not understand how autonomous cars reduce the need for that."

Even if it works for just highway driving in good weather--which, in spite of overall skepticism about timeframes seems relatively close--it's hard to see how it doesn't put a lot more cars on the roads. I can't believe I'm unique in saying that I'd go into the city after work or head into the mountains for a hike more frequently if someone/something else were driving me.

Operating costs are still a constraint And those are higher than a lot of people assume if they don't really think about it. But easier driving will absolutely put more cars on the road.