I think self driving and public transport are actually complimentary. The principal benefits of owning your own automobile are convenience, as it’s always available for your use, and range— it will go wherever you want. Enabling vast fleets of on demand taxis is already well underway, making owning your own vehicle less attractive. The next step imho is bundling rides together, making NOT owning your car cheaper still. For urban cores, I would expect shared self driving to crowd out private cars pretty quickly.

It will probably nearly eliminate individual car ownership which will free up a ton of real estate currently used for parking. Which will probably reduce congestion inside the cities. It may also reduce highway congestion because we can engineer it such that it knows how drive unlike most people on the roads today

And it is also inefficient because it is used in cars taking 4 passengers max so it can not really scale.

But if a bus, a tram or a train would have a self driving... but that smells like communism to our techbros from Silicon Valley.