[bluGill]

A train should never be put someplace without first trying bus service. If you can get busy bus service you know the train will be used. If you can't get busy bus service - well it is easy to try those same buses on a different route until you find where people actually want to go. (and then you can build the train there if the real numbers show it is worth it)

[burfog]

Are there buses in Boston? I lived there, and I wouldn't know. Buses are not something I'd contemplate using.

From experiences in other cities, where I looked into the matter:

Buses are too hard to use. Buses often stop on an unexpected side of the street, get rerouted, get cancelled, and have horribly complicated schedules. Routes even vary moment by moment. The crime situation is worse. The weather protection is worse.

I've never known anybody who would use buses. Buses are just noisy things that block traffic, damage pavement (proportional to 4th power of mass), and belch lung-clogging soot. AFAIK, they drive around empty, except that sometimes they serve as homeless shelters.