8. Teen Numbered Lines
Anyone navigating the subway system today might be surprised to see an 8 train passing by, or a 12, or a 16, but all of those lines once existed. The former BMT line used to have 16 numbered lines. Many of the numbers above 7 have been converted to the letter labeled lines and some were also turned into double letter lines. For example, the 15 became the QJ, and the 14 became the JJ, and eventually the J/Z. Zero is used internally by the MTA to refer to the 42nd Street Shuttle.
Trains labeled with the number 8 have been spotted and according to an MTA rep speaking to Gothamist, “Signs come with numbers that we don’t use like 8 and 9 in case we should ever want to use them. It was probably turned to 8 inadvertently in the yard.” Other numbers have also been spotted on trains.