MIDTOWN — "D" is for dirty.
Only 17 percent of its cars were deemed clean, plummeting from 49 percent in 2011, according to the survey.
Straphangers Campaign field organizer Jason Chin-Fatt said nine out of 20 lines surveyed saw an increase in dirty cars, something he attributed partly to an increase in ridership.
"More riders means more chances to spill something," Chin-Fatt told DNAinfo New York.
Subway surveyors rated cars as being heavily dirty for having opened or spilled food, rolling bottles, "malodorous conditions," sticky or wet spots and dirty seats.
The 1, 2, 3, A, B, F, N and Q lines saw at least an 11 percent deterioration.
The jam-packed L line seemed to contradict the increased ridership theory for the dirty trains. The L was found to be the tidiest subway in the survey with 63 percent of its cars rated clean, up from 58 percent in 2011, according to the survey.
Overall there was no line that saw a large improvement in cleanliness last year, Straphangers found, with 11 lines staying relatively the same.
MTA resources also appear to be not much of a factor in subway car dirtiness. The number of budgeted cleaning staff remained the same with 1030 cleaners and 141 supervisors in 2012 and 2013.
The MTA countered that Straphangers used a "flawed methodology" in rating car dirtiness well after they had been cleaned by transit workers.
"During the course of a round trip, customers can accidentally drop drinks, come in with muddy shoes or slush and salt during a snowstorm, but that is not indicative of our car cleaning efforts," an MTA spokesman said. "By conducting these surveys on subway cars in service, the Straphangers lessen the overall impact of our car cleaners at terminals."