The evidence has piled beside turnstiles and beneath benches, along subway platforms where riders found nowhere else to place their coffee cups or apple cores and on the tracks where tattered newspapers and crushed bottles seem to have taken up permanent residence.
Yet despite some riders’ resourceful disposal methods since trash cans were removed from two subway stations last year, the Metropolitan Transportation Authority says the counterintuitive plan has worked: trash hauls have decreased, it said, and the stations are cleaner.
As a result, the authority said, the pilot program has been expanded to eight more stations, including stops at 57th Street in Manhattan, Brighton Beach in Brooklyn, and East 143rd Street in the Bronx.
“I’m actually very intrigued by this,” said Joseph J. Lhota, the transportation authority’s chairman, before urging riders to treat the subway “as you would treat your home.”
Asked if the measure could eventually be extended into a systemwide policy, Mr. Lhota said, “It could be.”
At the two stations that have been without trash bins since last fall — the Eighth Street and Broadway station in Greenwich Village and the Flushing-Main Street station in Queens — the number of trash bags hauled out by workers has decreased by 50 percent and 67 percent, the authority said.
Officials have described the logic of the program simply: If there is nowhere to discard trash, riders will take it with them — often outside of a station.
Mr. Lhota said that prohibitions on garbage bins had been effective on the Underground in London and on the PATH system, which has been without bins since 2001 because of security concerns.
The transportation authority removes 14,000 tons of trash from the subway annually, it said. A spokeswoman for the city’s Sanitation Department said the reduction in trash at the two pilot locations had not burdened its collection operations at street level. “Sanitation has monitored these two locations and there has been no negative impact,” the spokeswoman said.
Some riders, though, have expressed reservations about the plan. Less trash, they argue, does not imply a more hygienic subway experience.
“I don’t know what to do with this,” Christopher DiScipio, 22, said on Thursday clutching a nearly-finished apple at the Eighth Street station.
Nearby, in a narrow alcove between a pay phone kiosk and a vertical beam, riders appeared to have fashioned a rogue receptacle. Detritus piled about three feet high — a mélange of crushed energy drink cans; bottles of water and, in at least one case, vodka; mounds of wrappers and paper cups; and what appeared to have once been a white T-shirt.
Dilu Chowdhury, 51, who operates a newsstand inside the station, said the surrounding area had become far dirtier in recent months. Customers often ask to use his trash bin. “I take it,” he said of customers’ waste, “but it is not enough.”
Still, it has not been all bad. Mr. Chowdhury has noticed fewer rats, he said, and riders’ quest for a trash bin at his stand has occasionally led them to unexpected purchases.
Gene Russianoff, the spokesman for the Straphangers Campaign, a rider advocacy group, said the convenience of travelers had not been properly considered in the plan. “If you have a big, drippy ice cream cone, what are you going to do?” he asked. “Stuff it in your purse?”
Mr. Lhota, who was known as the city’s “rat czar” as a deputy mayor under Rudolph W. Giuliani, dismissed this logic. “I think it’s better for the overall ridership to have the cleanest possible subway system,” he said.
On signs posted at bin-less stations describing the program, riders had already begun discussing its merits in writing, scrawling messages on posters reading, in part, “Trash is a problem.”
At Eighth Street, a rider wrote, in blue ink, “stupidest idea ever,” before apparently being bested by a traveler with black ink, who crossed out the first word.
On another sign, opinion was unanimous.
“Won’t work!” one message said.
“Put the trash cans back in!” read another.
“Agreed!” a third rider wrote.
A fourth, unprintable entry also expressed skepticism about the program.
This article has been revised to reflect the following correction:
Correction: August 31, 2012
Because of an editing error, an earlier version of a picture caption with the photograph of a cup on top of a pay phone misstated that the location was 57th Street. It was Eighth Street.