New York’s Metropolitan Transportation Authority made big news last month when it placed courtesy campaign ads on its subway trains urging passengers to “stop the spread” — that popular posture for men known, apparently, as “manspreading” that involves splayed legs and blocked seats.

Another New York ad told subway riders that train poles are “for your safety, not your latest routine. Hold the pole, not our attention.”

So far, BART and the San Francisco Municipal Transportation Agency have avoided such sassy, in-your-face New York-style etiquette lessons. But a couple of hours spent riding their trains and buses and talking to frustrated passengers who’ve seen it all — and we do mean all — shows that the transit agencies might want to reconsider.

Let’s just say Miss Manners would probably go into cardiac arrest if she saw what’s going on aboard some of these trains and buses. And it’s not just guys taking up too much room.

“Fingernail clipping,” said Brian Harrington, 39, when asked his No. 1 pet peeve about fellow BART passengers.

“This guy the other day was peeling oranges and dropping the peels on the floor,” said Tracy Benshoof, 41, who was riding Muni’s 8X-Bayshore Express bus. “I didn’t say anything. What’s the point?”

“People are really smelly,” sighed Michael Grassia, 52, riding the same line going the other way. As if to counter the stench, he carried a bouquet of white roses.

Other passengers complained of people shoving past without saying, “Excuse me,” listening to music loudly without headphones, blocking doors rather than moving to the center of the trains, trying to board trains before others have disembarked and wielding enormous backpacks, oblivious to those around them.

And then there are the overly loud cell phone conversations, such as the man on Grassia’s bus who could be overhead yelling, “Sabrina is a prostitute? How did you know?” Another man then slowed the same bus’ progress when he struggled to exit the narrow back door carrying both a guitar and a giant stuffed lizard.

Transit agency campaigns

New York isn’t the only transit system to adopt a memorable courtesy campaign. Seattle’s Sound Transit followed in New York’s anti-manspreading footsteps a few weeks ago and put up signs comparing the behavior to an octopus whose tentacles are everywhere. “We agree, one body, one seat. No #manspreading,” the agency tweeted.

The Southeastern Pennsylvania Transportation Authority last year instituted a “Dude, It’s Rude” campaign on the theory that direct messages with some humor are most likely to get people’s attention. Its slogans include “Two seats? Really?” and “Watch Your Language.”

It’s not that BART and Muni officials aren’t aware that their trains and buses can tend toward a mix of “Animal House” and “Lord of the Flies.” Considering that people make more than 1 million trips a day on BART and Muni combined, that’s a lot of potential for backpacks to the face and cell phone over-sharing.

BART spokeswoman Alicia Trost said the agency does have some ongoing courtesy campaigns, but that they’re very earnest — not at all like New York’s manspreading harangue.

Most common complaints

BART’s website has a “crowded car survival guide” with the basics about waiting for others to get off before you get on and placing backpacks on the floor between your feet. But it has all the flair of an in-flight safety demonstration.

“They’re just not in the tone of being silly and fun,” said Trost, who added that the agency conducted focus groups and found that passengers prefer the serious approach to the snarky. “The results were, 'We don’t want you to tell us what to do. Who are you to tell us that?’”

SFMTA spokesman Paul Rose said Muni is considering its own etiquette campaign and is surveying passengers about their most common courtesy-related complaints.

He said a campaign would probably tell riders not to lean on or block doors, not to leave large bags in the aisles or on seats, to give seats to seniors and disabled people, and not to smoke, litter, drink or eat.

Speaking of eating, Alena Johnson, 28, was waiting for a BART train at the 16th Street station while eating a bagel and drinking orange juice. Technically, that’s a no-no.

“I totally eat on BART,” she confessed. “I have no idea if it bothers people. But I’m not messy. It’s not like I’m eating pad thai.”

Riffs about eating, fingernail clipping and other unsavory behavior inspired the creation seven years ago of Muni Diaries, a website and Twitter account that gather the horrifying, amusing and just plain odd experiences of the Bay Area’s public transit passengers. There’s now a BART Diaries Twitter account, too.

Eugenia Chien, 37, co-founded Muni Diaries and said the stories just keep coming.

“It’s been seven years, and just when you think you’ve seen everything, there’s something new,” she said. “People think of Muni as their living room, they feel so comfortable. You see all kinds of weird behavior.”

Her recent favorites include two people giving each other haircuts and somebody who plugged a toaster into an outlet on a Muni train and made toast.

Courtesy in a crowd

A perusal of Chien’s Twitter accounts found that passengers have recently griped about, um, noxious gas emissions, somebody throwing up all over the train, somebody “humping the BART train door,” a woman checking her daughter for lice and somebody singing “I Will Survive” at the top of his lungs.

Chien said she thinks BART and Muni should adopt New York’s style of courtesy campaigns. So does Wynne Dalley, a Danville etiquette expert who’s written books including “Be Cool and Confident.” She said lots of people consider good manners to be outdated, but courtesy is essential when it comes to succeeding professionally and socially.

“Certainly young men are not throwing their cloaks over puddles anymore, so it’s changed,” she said. “But every generation should be polite.”

Surprise find on a seat

Dalley admitted she’s got an uphill battle ahead of her, but she’d probably be downright shocked had she heard a conversation among passengers riding the 38-Geary on their way to Kaiser Permanente.

“I saw a condom left on a seat once,” said Anne McEnte, 43. “It was used.”

Sitting behind her, Luis Abanto, 30, said he’d seen people having sex on the bus.

Across the aisle, Billy Kanios, 61, said he’d seen a guy shooting up drugs in the back row while kids sat nearby.

They continued to trade anecdotes as their bus rumbled up Geary. “You get some real stories riding these buses,” Kanios said.

As the bus came to a stop, Abanto said the conversation among strangers had been fun. Fun on Muni? Now that’s something nobody would believe.