A bus driver told me that it's against rules for folding bikes to go on the front bus racks. He said they have a sign posted at the bus station with a picture of a folder that says folders don't fit securely into the racks. That day, I had actually put my folding bike on 3 different bus racks where the drivers said nothing and let me do it. To me, this matters because I can't just fold my bike and bring it on board. I have a plastic crate zip-tied to the rack, and it can't be folded with the crate. Is it true that folders aren't allowed? Are they truly not secure on the racks? And if it's true they aren't allowed, is there something I could carry that would make it secure and allowed? (anything from a specific device to a bungee cord) I'm not going to buy a new bike, since the current one works fine for me. It's rare that I would want to put my bike on a bus - that particular day I had an errand downtown, then was returning straight to work, and it was raining hard. So it's not that I would use it often, but previously I always liked the idea that if my bike broke down or the weather got awful that I could take a bus with it.
I wonder if this is a safety issue due to the smaller wheel size? If so, then it could be a problem for kids' bikes, too.
@Salty: does @sprite still work in your building? I think she used to take a folder on the T and also on a regular bus.
If there is no such policy, maybe get an email from someone at PAT that you can carry with you?
Out of curiosity: what kind of folder do you have and how do you like it? I am always eyeing those.
Yeah, sprite uses the bus and T all the time with her folder, I'll ask her.
lolwut. I have a Bike Friday Tikit and I put it on a rack 4 times a day every weekday rain or shine (holidays excepted.) P1/P2 and 41 routes. In fact as soon as buses started to have racks most drivers were all like "dude, err I mean honey, you have to put that on a rack and not carry it on" (IIRC they are correct per the PAT "we like bikes" pamphlet of yore) and from that day forward I have had the perpetually renewed ghettoer-than-thou giant eagle baggie seat-cover because rain.
There is one driver that was nervous about it because granted 12 inch wheels are the lower limit of what the racks are designed to hold (they did *design* them to hold down to 12 inches) and there are one or two older/suckier models of rack that in practice don't hold 12 inchers that well (implementation fail: the hook doesn't telescope short enough by a hair)... my bike is secure from the hook falling all the way down because the hook can't get past the front rack (tikits have a bizarro one-sided front rack, look on bikefriday.com for pics if curious), but for him, I used to carry a short bungee cord and I would bungee the hook to the bike to hold it up toward a higher part of the tire and then he was all happy.
If you have larger than 12 inch wheels then they are very silly to think there could be an issue at all IMO.
I'll go with sprite's recommendation. Granted there are at least four styles of bus racks I am aware of, depending on when they were purchased, and they're deployed throughout the fleet (i.e., I can't simply say such-and-such style of bus has Brand A vs. Brand 
. But if she's got all that usage experience -- and she's using buses from both ELib and Collier garages -- and if the wheel sizes are comparable, then there really should be no problem.
Interesting replies, so far - thank you all for writing! I have a Dahon Speed D7, which has 20" diameter wheels. Far larger than 12 inch! Definitely it's important to know the racks are designed to hold down to 12 inches!! Does someone have a link to the rack type where I could find that info? Also, does anyone here work for the bus company? I'd be interested to know if there's really a picture up saying these bikes aren't allowed. The bus driver seemed honestly apologetic, and I believed him when he said that was official policy. If it turns out the racks are designed to fit my size wheels, and that sign really is up, then I want to contact someone about changing that rule. I want to start that conversation with all facts in hand, though.
I'm keeping the folder now because it fits me and it's free, as opposed to the cost in time and money of buying a new/used bike. It was super-practical in NYC, when I lived on a 5th floor walkup. After having a bike stolen that was chained up outside overnight, I kept my bike in my apartment overnight like most people in the city. But as a person with one weak shoulder, I need a bike that lets me sit upright (usually heavy, large-height bikes awkward to carry upstairs). As a small person, the only kind of bike like that which I could carry up 4 flights of stairs is a folding bike... even though it's just as heavy as other comfort bikes, the smaller size when folded makes it comfortable and safe to carry. So, for NYC a folder made it possible for me to have a bike in the city. However, since I needed to fold it there couldn't be a crate attached, so it wasn't practical for grocery shopping in NYC. Which is also kind of interesting, in NYC lots of people use rolley carts for grocery shopping and bringing laundry bags to laundromats - I only see elderly people doing that here in Pittsburgh, and I wonder why! I see a lot of people painfully lugging bags of groceries (sweating and looking unhappy) from the big grocery stores around here, and that especially makes me wonder... a rolley cart usually costs like $25, and they have them at all the drugstores in NYC. Anyways, back to the folder: I'm a big fan of practical bikes with crates, and here in Pittsburgh I don't need to fold my bike to get it in my apartment. So if I didn't have any bike right now, I would buy a full sized comfort bike.
p.s. Sprite, so neat to get advice from you, since you have a ton of experience riding buses here with a folder. Thank you!!!
"I believed him when he said that was official policy":
Yeah, I used to believe drivers too. If I had a nickel for every time someone was making up policy! (Not always the bus/T drivers; sometimes it is the people who train them.)
You can file a feedback via the portauthority.org web page or the phone number, saying that you were told the policy is x but that the policy is really "folders MUST ride on the rack if the bus has one"; or if you know people who know people, you can pass the info that someone at whatever-garage-it-is is telling people the wrong policy... I used to escalate through my employer (I haven't had any issues since buses went all-rack and the T went bikes-anytime, partly because the drivers on my routes are pretty used to me and because I rack a bike like I've racked it 1000 times before which at this rate probably I have.)
Here's PAT's page where they state you're required to put your folding bike on the rack. Maybe carry a printout or the PAT bike pamphlet to show the driver in case it happens again?
But definitely report the problem.
@LoriF "I'm not going to buy a new bike"
This is incorrect. 
Number of bikes you need is N+1.
Folding bikes are allowed (moreover, required to be) on bus racks.
Ditto, only I'd use the Complaints form link on that page. Be as factual as possible, but as detailed as possible.
If you cannot get the four-digit driver number (on their left breast pocket), then at least get: Bus number, bus route, direction of travel, exact spot where this happened, date, time of day. With that, they can positively identify which driver it is.
Example: 71C, inbound, bus 5429, Ellsworth at Summerlea, Thursday 8/23, 2:17 pm.
When I called Port Authority for a lost and found case, I gave them all that info except for the bus# (I didn't have it), and they were able to identify which bus it was based on the rest of the info.
I did used to gather all that info, though, if a bike rack was broken (I always used to get broken racks, and I'd tweet the info to their twitter account. Pretty sure they didn't do anything, but it made me feel better for the moment)
I always used to get broken racks
I've run into a lot fewer broken racks on buses this year. Last year I reported at least six; so far this year I don't think I've encountered any.
Thank you all for this great information - you folks are awesome!!! I just now submitted the complaint by the webform, and referenced the URL of their webpage where the 16"-and-up wheels are allowed. Yay - feels much better to do something to fix the problem than just complain (to folks who aren't able to fix it)!! Thank you!!!
