We've all been there: you’re having a pleasant ride on a Bay Area train or bus, only to get rudely smacked by someone’s bag.

SFMTA and BART officials have received complaints about the problem, but “of course” there is no direct policy to address it, said BART spokeswoman Alicia Trost.

However, her agency has put posters in many BART cars asking riders to please remove their bags and put them between their legs, she noted.

“It is an absolute fact: if everyone took their backpacks off and put their bags between their legs, we could fit more people on our train cars,” Trost said.

Some forthcoming BART cars offer remedies to the bag issue, she added. The agency’s “Fleet Of The Future” cars, a $2.6 billion project set to debut later this year, will have added room underneath seats for passengers to store their bags. And a new extension to Antioch will have cars that have luggage racks.

SFMTA similarly has signs asking people to be polite and also to keep aisles clear of bags. Muni trains and buses frequently have room for bags underneath legs, but they don’t have luggage racks or other remedies planned.

But “one the benefits of the new trains is they have more room,” said Muni spokesman Paul Rose.

He echoed Trost’s call for politeness, noting SFMTA has received its share of complaints on the issue.

“Common courtesy goes a long way,” Rose said. “We ask our riders to store the bag under the seat, on their lap, or in between their legs.”

Here’s what some Bay Area residents said on the issue:

Andrew Steven Kent, Ingleside

“Too often I keep getting poked and prodded by purses and on a crowded Muni bus. And it's not just once. It's multiple times because the person doesn't realize what's going on.”

Janel Brynda, Noe Valley

“They need to be taken off and held at ground level on a crowed train. Not only does it make more room, but as a short person, I would prefer not to have your backpack bumping into my face or head.”

Topher Olson, Castro

“Sure, there are rude people, like the guy using a seat for his backpack, who need to wise up. Then, there are people in ordinary situations like returning from the store with groceries who deserve our understanding. But, I see that only occasionally. Mostly, I see that trains and buses are crowded. The problem isn't the bags; it's inadequate transit.”

Garrett DeHoyos, Millbrae

“I didn't even know taking off your backpack on a crowded train or bus was a thing you were supposed to do until last year, when I saw a sign on BART about it. Now that I'm cognizant of it, I always take off my backpack when needed.”

What are your thoughts? Let us know in the comments!