Luckily for the Autonomous car they are competing with totally crap human drivers. Its difficult to imagine a system that could drive worse than 90 % of humans.
"The reality: huge sums of money are being spend on small biz" is this some kind attempt at a Xenophobic joke or indicative of the care taken in writing this article?
Seems to me it has always been a moral issue looking for a scientific justification..... Not the first time this has happened. The major issue I see is that most consequences are unintended and unpredictable except in the simplest systems.
If you think these things can make the traffic worse then you obviously live in a country where the humans can drive. I live in California, where nothing, man , beast or machine could be more inept than the local drivers. Maybe that's why google is optimistic.