Thanks for reading! I discussed both of the lines you quoted at some length, bringing up and discussing all of your points, I think, and linking research from experts in the field.
In the worst case an autonomous car is just as space efficient as a human driven car (ie. a single person in a compact car still takes up quite a bit of room) and if this case is fairly prevalent it’s hard to see how traffic congestion changes much. Even if parking goes away, city councils may be eager to reclaim that space for pedestrians, cyclists, and parklets.
The question I’m most interested in is whether city governments will accommodate the increased demand that autonomous cars potentially induce with more road capacity, leading more cities down the path of Houston and LA with more and more land used for highway construction, or whether cities will take the approach of Vancouver and Paris, establishing policies to freeze and reduce the land space allocated to automobile exclusive transportation.