The MTA is rolling full speed ahead to wipe out the scourge of “manspreading” on subways and buses — but the phenomenon hasn’t petered out yet.

New courtesy ads featuring 12 images that chastise riders for their nasty behavior started going up over the last several days on subway lines around the city, yet some oblivious men are continuing to ride the rails with their legs astride two seats during rush hour.

One commuter spread his legs comfortably out on the J train, even though his car was packed with people.

Acupuncturist Heidi Kothe, 38, of Greenpoint, said she didn’t think the placards would have an impact.

“They’re never going to stop it,” she said, but noted that she would fight back against the scourge. “I’ll push people’s legs closed, I don’t care.”

But others told The Post they were starting to see small changes in people’s behavior.

“Some guys do close their legs more,” said Williamsburg film student Rene Vasquez, 27.

The ads also tell riders not to eat off seats, clip their nails or dance on poles.

“Clipping? Primping? Everybody wants to look their best, but it’s a subway car, not a restroom,” says one sign, showing two straphangers overwhelming a man in a suit while grooming themselves.

Another reads, “Poles are for your safety, not your latest routine . . . A subway car is no place for showtime.”

Kevin, a subway acrobat from East New York who performs on the A and E lines, said he’s already seen a hit to his bottom line since the ads went up.

Before the campaign he made about $80 a day, but is now taking home only $20.

“They are not giving us money in most of the cars,” he said.

Riders are also admonished to let people off before boarding, and to not wear bulky backpacks while traveling.

MTA chairman Thomas Prendergast said in December that many New Yorkers are “afflicted with the disease” of not letting riders leave before entering.

Some riders didn’t like the ads, and said they wish the MTA would target panhandlers and musicians.

“Where are the no mariachi band signs?” said Martin Jean-Pierre, 34, of Bedford-Stuyvesant. “Where are the signs that say this is a subway, not the Red Cross?”

The scolding images will soon go up on buses and railroads as well, after the ads are placed in the MTA’s 2,600 subway cars.

The politeness push was started to help riders deal with the record number of people riding trains.

Additional reporting by Matt Abrahams