Why New York City Subway Trains Use Letters and Numbers But Share the Same Colors

Rida Ali of Rozana With Rida explored the history of the New York City subway system at the New York Transit Museum, where she learned why some trains are identified by letters while others use numbers. She also learned why different services share the same route colors.

Ever wonder why NYC subway lines aren’t alphabetical, or why completely different trains share the same color? The system makes a lot more sense once you realize the colors represent the major Manhattan trunk lines, not just individual trains. I learned so much of this history from the New York Transit Museum, which is genuinely one of the best places to understand how the city’s subway system evolved into the beautiful, confusing map we know today

New York City’s subway system originated as three separate systems: the privately operated IRT (Interborough Rapid Transit Company) and BMT (Brooklyn-Manhattan Transit Corporation) and the city-owned IND (Independent Subway System). In 1940, the city acquired the IRT and BMT and unified all three under municipal control. Today’s numbered routes descend from the IRT, while the lettered routes descend from the BMT and IND. The current color system groups services largely by their major Manhattan trunk lines.