It doesn't work for outlying areas. The further you get form a hub, the more varied the travel plans are. Express services work for connecting hubs. But it's the 30-60 mile out suburbs that are a challenge.

Note, they are only a challenge if bureaucrats and big business continue to pour money into centralizing resources in giant cities. In a modern Internet connected economy, there is very little reason to colocate so many government services and large corporations.