I asked this ques. a few years ago, and got no responses with info I didn't already know, maybe someone now reading this has new info. Question: besides the passageways at (1) Rockefeller Center, (2) Lincoln Center, (3) Wall Street area, (4) Grand Central Station [all of these are outside fare control on the subways], (5) Times Square Station, (6) Broadway Nassau Street [these last two are within control] are there others?
[Note, for example, in (5) you can get from 44th and 8th to 43 and Broadway, without going out in the street. With (5) + Port Authority Bus Terminal, you can get from 40th and 9th Avenue to 43 and Bway.]
Terminal. It's Grand Central Terminal.