And there will be hundreds of them on the road at any one time, empty vehicles idling behind one another because the company decided that was the "safest speed"

And there will be hundreds of them on the road at any one time, empty vehicles idling behind one another because the company decided that was the "safest speed" to maximise their profits, taking up the roadways to hinder much more efficient public transit, and slowing everything right down. The companies will then likely pay off the city to let them use mass transit lanes, or to allow them some priority over other drivers. If you think this is hyperbole, consider Netflix's great win in the Net Neutrality fight.