Unused New York City Subway service labels

Several New York City Subway service labels have never been used, but have appeared on rollsigns. DD, FF and MM are covered in the D, F and M articles. The others are included here.

IRT numbers

Current rollsigns include the following:

• Green 8, 10 and 12 (the same color as the 4, 5 and 6 and the diamond services of the 5 and 6)
• Purple 11 (the same color as the 7 and its diamond service)
• Red 13 (the same color as the 1, 2 and 3)
• Red 9, unused since May 27, 2005

It is likely that these were assigned arbitrarily, for use if a new service is inaugurated over existing trackage.

IND/BMT letters

P, T, U, X and Y appear on current rollsigns as a black number on a white circle. No current services use this color, so the signs would likely be patched if any of these services were to become permanent. Specifically, T is the planned label for the Second Avenue Line, and would be colored turquoise.

In the 1990s, P (short for Penn Station) was planned for a nonstop between Sutphin Boulevard-JFK Airport (at the LIRR's Jamaica station) and 34th Street-Penn Station, continuing locally to Washington Heights-168th Street, via the BMT Archer Avenue Line, BMT Jamaica Line, Chrystie Street Connection, IND Sixth Avenue Line and IND Eighth Avenue Line (swtiching between the latter at West Fourth Street-Washington Square). This would have been used during threatened Amtrak strikes that would have prevented LIRR trains from entering New York Penn Station.

P was skipped in the 1960 assignment of letters to BMT services, possibly because of the slang use of the word pee ("go down to track four and take a P", and the fact that the local of the P service would have been PP at the time). Others speculate that it may have been reserved for the BMT Culver Line, which was converted to a shuttle in 1959. No evidence has been found for either claim. T was used for BMT West End Line services, but was quickly eaten up by the post-Chrystie Street expanded B. Y has at times been proposed for the Second Avenue Line, though the current plan it to name it T.