Seriously, what does that even mean? I ride the subway every week, and no amount of money is going to make that a better experience than door-to-door self-driving cars. Subways operate on their schedule, not yours, and they often drop you off several blocks from your ultimate destination. And at the risk of sounding like a "fear monger," subways are often full of people who have mental health and other issues.

Also, public transit is incredibly expensive compared to a fleet of self-driving cars. So why would I want to invest in something that costs way more per ride (once you count the amount taxpayers are subsidizing) and is far less safe and convenient and comfortable? For Exhibit A, see California's high speed rail boondoggle. For the projected cost of the rail line from San Francisco to LA ($130 billion), CA could afford to fly every single person in SF to LA every single day for seven years. If we say once per week, it would be for 50 years. The CA high speed train might be the biggest waste of money at the state level in human history.