M_train_canal The Straphangers Campaign released their latest “Shmutz Survey” and the M train won the top honor of being the filthiest line with less than 1/3 of subway cars rated as clean. On a whole, the entire system also got dirtier. The MTA’s austere budget which cut down on the amount of cleaners is blamed for the uptick, although the slovenly, reflexive littering by some subway riders should also be taken into account. |NYDN|