Perhaps because the MTA signs trying explain weekend subway service diversions are confusing--like this weekend F service sign--the MTA has put up some maps to try to explain changes, too. For instance, here's a map explaining service updates for the 2 and 5 lines.
While the 2 usually goes up the West Side and the 5 the East Side, the uptown 5 is running on the 2 line in most of Manhattan and the uptown 2 is making stops on the 4/5 in Manhattan. Let's say you're in Brooklyn and were planning on heading to the Upper West Side--you'd have to take the 4 train into Manhattan, get out at Bowling Green, walk downstairs and then back upstairs to the downtown tracks to catch an uptown 5 train--if one ever comes (last Saturday afternoon, we waited about 40 minutes for an uptown 5).
The NY Times' Clyde Haberman's column details the woes of weekend subway ridership--did you know 4.8 million people took the subways on weekends, the highest level ever. You can sign up for weekly and weekend subway service advisories from the MTA and from the Straphangers group.
Oh, and there are no 3 trains running (there are buses), the A stops at 168th Street, there's no C...