Communally shared cars would still have the problem that a large number of those personal cars are spending the same 90% of their time sitting in a parking spac

Communally shared cars would still have the problem that a large number of those personal cars are spending the same 90% of their time sitting in a parking space. Everyone's leaving for work at 8, leaving for lunch at noon and leaving for home at 5. You'd still need roughly the same number of 'communal' cars during those peak times. Though people may be more likely to car-pool. Even the trivial variation of most US 'flex time' starts wouldn't help much. The difference between 8 and 9 isn't great enough for very many cars to make it from a business park at 8 back out to pick up another passenger and then back to another employer before 9. What might really help, is 'communal' cars augmenting the US's sparse transit system. e.g. The communal car takes you to the train/bus stop. A communal bus departs as soon as it can. The communal car takes you to your final destination. That way the cars are doing shorter round-trips, serving more people (necessitating fewer cars) and people are more apt to use the public transport because they aren't worried about the current big problems of US transit: 1. parking at the transit stop 2. how to get from the transit destination to where they really want to go 3. what happens if you miss the train/bus time (the car can just complete the trip)