Cars take up too much space. Relying on cars instead of mass transit means everything has to be more spread out, which makes walking and biking a lot worse.
If everyone can share a small fleet of self driving vehicles, they don’t need to take up a lot of space at all. I’m assuming you were talking about parking space; I don’t see how self driving cars would take up significantly more space than mass transit while on the road.
> If everyone can share a small fleet of self driving vehicles
They cannot.
> I don’t see how self driving cars would take up significantly more space than mass transit while on the road.
They would take up more space because they're cars. Cars can't get to similar efficiencies of space compared to buses unless you compared packed private cars with sparsely ridden buses. And then of course, there's trains.
Perhaps someday we'll have all self driving cars that can safely coordinate and pack themselves into smaller spaces on the road, but that's decades away at a minimum, since you'd first need to get rid of all manually driven cars.
Trains are a very inefficient use of space. Trains often run nearly empty, and the tracks can only be used by trains. A road (utilized by autonomous vehicles) can be used at any time and any schedule by any vehicle, including the possibility of giving automatic intersection right of way to pedestrians, or safely sharing road space with personal transport (bikes, scooters, etc.)
If a thousand people try to go to work at the same time, the car being driverless or not will not result in less than a thousand cars being driven, and the number of cars in the road is the biggest cause of congestion.
However, a bus can carry a hundred people comfortably. Ten buses instead of a thousand cars results in much leas congestion.
Well, not exactly. The good thing is that automated, centrally booked autonomous systems can run pretty good car pools. Sure human drivers can do this but it's just not as practical. Not at all. So it's possible that those 1000 people might be served by 500, 300 or maybe even 250 autonomous cars.