I don't get that one. Cars are mostly fine if they don't pollute. They'd just be large bicycles. Why do you think the concept of automated personal transport is "the problem" ?

I think for instance we can't possibly build enough railway and bus network to serve every inch of the territory and it's simply to allow fast speed individual transport to distribute the load. It can be even automated with no pilot control, but it's impossible to schedule-base every location in a city without displacing people, rebuilding cities entirely around specific common transport etc. In Europe and Asia, where we build a lot of cities organically, it seems silly. In the US, where cars are even MORE prevalent to the point cities are built for them rather than humans, it will never disappear.