of course, the Green line is the line by Fenway (Kenmore on the B, C, and D branches, Fenway on the D (Riverside), St Mary's on the C (Cleveland Circle), and ??? on the B (Boston College)). Don't listen to half smokes on this one. The Green line is LRVs that go through a subway then on the surface. I grew up on the green line, take it still. The whole system is a bit grimey. Feel free to take your Dunkin Donuts coffee on board the T.
i commuted down commonwealth on that thing- i hate it with a passion, the only thing worse than waiting for it in the winter, was ball games in the summer when an extra helping of drunk sweaty BC and BU students would make it even more crammed, if you stay on the red line, then you're taking it out from park street and avoiding most of the students