The key thing that privately-owned cars have over on-demand cars is reliability, and the illusion of control. I've owned an unreliable car (It had trouble star

The key thing that privately-owned cars have over on-demand cars is reliability, and the illusion of control. I've owned an unreliable car (It had trouble starting, but would run fine once started). It sucked. Not knowing if the car would start each time changed my relationship with going places and doing the things I wanted to do. I had to budget extra time everywhere I went, in case I needed to jump the car or wait for AAA. On-demand cars will have many of the same problems, just due to demand surges, and traffic. Sure, you can get stuck in traffic any time. That's true, but you feel it less when you have the illusion of control of driving. When the traffic delays your inbound car by 5 or 10 minutes and you're just standing on the curb waiting for it, that feels more aggravating than when you're behind the wheel. I also think there will be a significant fraction of the population that uses their car as personal, daily storage. My wife keeps a bunch of stuff in her car, and would be significantly impacted if she had to take it all in and out every time she went everywhere. Same thing with kids car seats, etc. I think on-demand cars will probably replace second commuter cars for families, but there will still be many, many owned-cars as well.