It's ironic that the example he gives for driving across LA already has a fast train connection:

> People that live in LA, I mean try to get from Pasadena to El Segundo during rush hour. You can fly to another city faster than you get to crosstown LA. And you have to drive the whole way.

You can take the Metro A line from Pasadena, then transfer to the C line to get to El Segundo. No driving necessary. Musk sells cars, so of course he has a massive incentive to say more cars are the solution to peoples' transit woes. But it seems like throwing more cars at the problem will simply make traffic worse, and from my experience living in Chicago, the best solution to avoid traffic (and parking!) is to take an alternative mode of transit that can bypass it (e.g. train, bike, electric scooter).