Assuming most travel occurs in the morning and evening rush hour, in your scenario some proportion of taxis only ever get used for those commutes. So at the ext

Assuming most travel occurs in the morning and evening rush hour, in your scenario some proportion of taxis only ever get used for those commutes. So at the extreme you have taxis that are used as much as private cars. So I would guess a self driving taxi fleet would have a higher cost than you, and there would definitely be room for buses and trains etc too.