It’s an express train — to the bad old days.

Cops are giving homeless people and panhandlers in the subways the kid-glove treatment, arresting subterranean scofflaws far less frequently than just two years ago, data show.

The ranks of the homeless in the subways, meanwhile, have swelled to 1,841 this year — a 13 percent increase over last year’s tally, the city’s Department of Homeless Services says.

For straphangers, it has created an atmosphere of fear.

“I feel threatened, especially taking the train at night,” explained Brooklynite Lortashia Smith, who said she has been followed off trains several times. “The police can definitely do more.”

The NYPD said panhandler/peddler arrests in the subway have increased over the past year, with 409 pinched so far in 2013 versus 395 in 2012. But those numbers pale in comparison to 2011, when it was reported that in a six-month span that year, a whopping 930 panhandlers and peddlers — the two are not separated in the data — were arrested.

“There’s been a drop-off,” acknowledged one police source.

The NYPD refused to provide full-year data for 2011, when cops were busy cracking down on underground quality-of-life issues as part of a Transit Bureau initiative called Operation Moving Target.

At that time, the NYPD explained arrests were up because of a targeted effort by the Transit Bureau to tackle quality-of-life offenses, which can lead to worse crime.

Late Saturday, an NYPD spokesperson said a comparison to 2011 data is not “apples to apples” because the department removed arrests for soliciting and selling MetroCard swipes from the panhandler/peddler category last year.

One city leader said the stop-and-frisk backlash could be to blame for the drop.

“Police are much more hesitant to be proactive and approach people who may be committing low-level crimes because of anti-NYPD sentiment that’s been growing in political circles,” said Councilman Peter Vallone Jr., who chairs the City Council’s Public Safety Committee. “If you are too afraid to approach, then crimes like loitering, open containers and aggressive panhandling will go unpunished.”

That, in turn, can be dangerous.

“Once you allow low-level crimes to fester, more dangerous crimes follow,” Vallone added.

Peaceful begging is allowed above ground, after state and federal courts ruled the state’s 1964 anti-loitering law unconstitutional.

But in the subway system, where the MTA establishes its own rules and regulations, all panhandling — peaceful included — is illegal, according to the agency.

The Department of Homeless Services said it maintains an outreach team dedicated to finding specialty housing for subway hobos.

Straphangers told The Post they’ve noticed an alarming increase in vagrants and beggars.

“Straphangers can’t actually get a seat on the subway because they are taking up the subway space,” said Brooklyn commuter Robert Scarborough. “They don’t wash. They have an aroma.”

Even panhandlers are scared.

“There’s more people down here,” noted Sarah Colon, who said she has been homeless ever since Hurricane Sandy. “The city’s not doing what it’s supposed to be doing. They need to make the shelters better than what they are now.”

Things could get a lot worse.

“I believe this can turn into ‘Mad Max’ down here,” said Maurice Solomon of The Bronx. “It’s a safe haven — it’s warm for them, and people give them food.”

Additional reporting by Brad Hamilton