@Larry F54; Re: Having cars that will park themselves will also free up space in cities
Just because you're happy with random strangers in your car, or a significantly longer commute while you drive around picking up people you work with, does not mean anyone else is
And don't try the argument of "people car sharing could drive to the home of the person driving the commute" because that doesn't deal with the amount of traffic on the roads, just moves it around and worsens local congestion.
Not everyone lives in close proximity to their work colleagues, and there's a dozen reasons why work colleagues might be unwilling, uncomfortable, or find it outright inappropriate to car-share with other workmates.
IMHO the way to reduce traffic on the roads requires multiple synchronous, complimentary solutions.
Removing the need to commute in the first place would be a good start. Not every job can be done from home, but many can with common technology and the right managerial mindset. Tends to be the overbearing micromanagement types that are most resistant to the idea of remote working.
Stagger school start and end times perhaps, for different schools in an area or even different year groups in the same school.
Stagger work hours so there's no big peak morning and evening rush.
Stuff like that.
Saying people should car share is simply failing to address the issues at hand, and will not make the impact you thing it will