Walker's overarching thesis is that city transit is undermined by "elite projection," where rich people pretend that the way they like getting around -- in private vehicles that go from door to door -- can possibly work at urban scale, despite the fact that simple geometry shows that this is a physical impossibility.
As in, "It doesn't matter how tightly you pack self-driving Ubers together on our roads. If all the people who make your coffee and empty your wastebin are in private vehicles rather than on buses and trains, the roads will be at 5 or 10 times their physical capacity." [...] These all share the geometric flaw: even the smallest cars, packed as tightly as possible, multiplied by all the people who rely on buses and trains, will overflow all the roads we have now and all the roads we could ever build.
There is another flaw: when you make it cheaper to ride private vehicles (rather than public transit), you siphon transit riders out of the buses and trains, and put them on the roads, increasing congestion: so adding "efficient rideshares" actually makes transit worse, not better
Walker tried to explain this to Elon Musk on Twitter [...] Musk called him an idiot.
The elite belief in Uberized, Muskized cities is at odds with fundamental, irrefutable facts of geometry