The Subway Is Byzantine

My last two trips to New York I have fared very poorly on the Subway System: previously, we took the B instead of the D on the way to the Met and ended up in Queens-- and this was certainly our fault, and alcohol consumption may have been to blame-- but this time even local Manhattanites were shaking their heads: after we ascended many stairs with the toddlers in tow, there was an 8 by 11 piece of paper instructing us that the A and the C were running on the local lines because of construction, and then after descending many stairs and taking the A we found ourselves whizzing by the 81st St. Museum stop, and then we kept going and going and finally we disembarked at 125th and took the downtown A to 59th then switched again to the uptown C to get to the Museum (it was funny hearing Alex saying "Why can't we catch the Local C?), and so on the way back we figured we had it down-- just take the C, take the local and we were guaranteed to stop where we wanted-- but as the D rolled by the conductor shouted out her window, "TAKE THE NEXT D! THE C IS ONLY RUNNING ON THE EXPRESS!" which we did and then switched again (it was easy, the train was waiting) but still . . . in the greatest city in the world should they be relying on taped up pieces of computer paper and shouting as their method of information dispersal?