We love to receive inquiries about little-known facets of New York City. Recently we received a question from six-year-old Charlotte, an astute second grader in Brooklyn. She asked what the tiny white signs on subway stairs stand for. We reached out to the MTA and our expert Underground Subway tour guides for the answer.
The white signs are identifying labels that appear on a step riser, usually close to the middle or top of the staircase. The short code on each label reveals the staircase’s location. An “M,” “S,” or “P” are always the first letters to appear in the code. “M” stands for mezzanine, “S” stands for street, and “P” stands for platform, indicating which level the staircase can be found.
The number in the middle of the code identifies which specific staircase you’re on within the station. Since the stairs in the photo below are labeled with a “7,” we know there are at least seven staircases in that station. The final letter, “A,” “B,” or “C,” will identify the “channel” of the staircase in cases where it is wide and has multiple sections. In the photo above, the channel on the left is labeled “P4A,” while the right side is labeled “P4B.’
MTA workers use these labels internally for wayfinding and reporting. For example, they may note that “M7B” needs to be repaired. One commenter on a Reddit thread suggested that riders can use the labels for directions. “I can remember to take staircase S8 down to my train, or give instructions like, ‘Go up S8, to platform 2, wait for the N,'” they wrote.
The subway is full of tiny surprises if you look close enough. This stair label inquiry brings to mind another question we dove into, where do the phone numbers on subway doors lead to? Find out here and learn more secrets of the subway on an upcoming underground subway tour. It’s the perfect time to dive into subway history, as the transit system turns 120 years old this October! Celebrate the milestone with the creator of our subway tour, Justin Rivers, with a special live-streamed tour where we’ll reminisce on opening day in 1904.
Underground NYC Subway Tour
