Walter S

What does "successful" mean? That it exists and people use it? Besides convenience, you also have economic drivers. In my area many people use public transportation and would probably rather not because they can't afford cars. The rail takes people to the outskirts of the city where they have jobs. There's also a sort of stigma that goes with using public transportation - not a dramatic one. But it's a factor. Many people seem to perceive using public transport as something for poor people.

If you introduce buffers where cars can't go then using public transport can actually save time. But how do you do that in the face of the public outrage that comes from people that already go to these places in their cars? Without that, public transport is for poor people or people with environmental concerns that do it out of a sense of responsibility. There's also people that use up some extra time on public transport, but spend that time reading, emailing with friends, etc. and do in fact prefer that way of getting around because driving takes constant attention. But that's a small segment of the population at large.