I think it can drop or stay the same if the costs of driving by yourself and owning a car rise sufficiently. You can do this by implementing congestion pricing

I think it can drop or stay the same if the costs of driving by yourself and owning a car rise sufficiently. You can do this by implementing congestion pricing and heavily advantaging carpool vehicles on the road by giving them more dedicated lanes, or by restricting single-occupant vehicles to a single lane on highways. In urban areas, renting a parking space for your own car is already quite expensive. It's an easy decision to give your car up if robo taxis are cheap and plentiful. In suburbia the calculus is a bit trickier because there's still a bit of keeping up with the Joneses. But there are many who'd jump at the chance of getting rid of their garage and driveway and have more living or personal work space. I agree with you about Tesla autopilot.