On the ones I’ve seen, the drain is near one end of the trough, and you’re supposed to face that end. The result is that your excrement tends to land on the open-air end of the trough, and remains unsubmerged until you flush. So the other disadvantage is that squat toilets (at least the ones with thsi design) really, really smell terrible.
Years ago, my husband and I were at our son’s hockey game. My husband never sat in the stands, he always hung with the other dads down at the boards. Between periods, I went down to the concession area and my husband scurried up to me looking nervous. He told me that he accidentally went into the women’s washroom. Perplexed, I asked him how in the world had that happened. He pointed to the sign painted above the women’s washroom door. It said OMEN. The W had worn off. Apparently, OMEN is the same MEN in his mind! 
When he went in, a woman came out of one of the stalls. He apologized and exited. If he hadn’t seen her, he would have used that washroom! He did say he wondered why there were no urinals.
I didn’t know if I’ve ever walked through the wrong door accidentally, but I’ve sometimes blundered into the men’s room in those hotel bathrooms that just have a bent corridor instead of a door. I’ve noticed before entering a stall, usually because i see guys in it. I say sometime like, “opps, sorry” and turn tail.
Good point. There’s a tremendous difference on mistake potential between a restroom with a door and one without.
The vast majority of my public experience is the large venues like airports, hotels, and shopping malls with no doors. So the sign(s) are someplace along the corridor leading to the privacy turn where you finally can see into the restroom proper.
At smaller venues, eg. restaurants, where there’s a door to a smaller space, typically a sign is on the door proper or immediately adjacent to it. Plus maybe other signs farther upstream in a corridor.
Going into the wrong place when there’s a gender sign on the door you’re opening right at your eye level is a much harder mistake to make. Assuming the sign doesn’t say “OMEN” or “Gulls” or some such silliness.
I’ve been to a couple of kd Lang concerts. Although I technically used the “right” restroom, I don’t think that there is a wrong restroom there.
This type of entrance is what I was referring to upthread where one does not immediately see the row of urinals when first ‘entering’ the restroom.
A lot, but it was due to an odd circumstance. I used to work in a building where my company had offices on 3 different floors. As you’d expect, the restrooms were in the same location and next to each other on each floor. As you wouldn’t expect, the mens/womens rooms were reversed on one of the 3 floors we were on. I spent most of my time in my office on the engineering floor, but spent enough on the reversed floor that I routinely opened the door into the wrong restroom. Luckily I always realized it before taking more than a step or two, but it was still embarrassing.
And does not, therefore, have any immediate cue even upon entering the restroom as to which gender it’s meant for; at least, unless there are others present clearly presenting as one gender of the other.
Plus which, as men’s rooms exist which don’t have the urinals immediately visible upon entering, someone entering a restroom can’t immediately tell from the absence of immediately-visible urinals that it must be a women’s room – because it might instead be a men’s room designed so that the urinals are behind the stalls or sinks. This might be true even if the entrance has a door.
As far as reading signs – people don’t always read signs, of any sort. I have three large signs up at my farmers’ market stand saying that I take FMNP coupons, and it’s still very common to have customers ask whether I take them. And how often have you pushed on a door that says Pull, or vice versa?
I think people do more often read restroom signs – but I’m not at all surprised that sometimes we/they don’t.
ETA: I’ve also been in more than one any-gender restroom that included a urinal. So a woman mistaking a single-use men’s room for one she can use might be mistaking it for an any-gender (sometimes labeled “family”) room.
Only once, back when I was attending a school for the gifted. But there was some weirdo sketching me from across the street, so I had to run inside and report him.
I’ve done it more than once; and have also seen others doing it.
And someone urgent to empty their bladder is also likely to be distracted and hurried.
Once. In the very first day of my very first job when I was unfamiliar with the layout of the place (or, apparently, with bathroom signs 
). Fortunately there was no one around and I got the hell out of there!
In this day and age…I’m actually not sure.
Not my personal anecdote, but a male friend went to the Lilith Fair Concert. Women out numbered men a bit. And in any large public venue there is usually a difference between male/female restroom lines.
Well a fair amount of women openly, proudly, decided to use the men’s restroom while my friend was in there. My friend and the other males had quizzical looks. But didn’t really care. As my friend related, they were confused exactly how some of them used the urinals.
Never been to Germany? Even the sit-down toilets have a shelf enabling you to inspect your stinky excrement before flushing it down…
This. The smell is overpoweringly Not A Ladies Room. I may have opened the wrong door once or twice but I never went in.
I have often done this at various bars, concerts, etc. and I’m never the only woman going into the men’s to avoid the stupidly long line. I’ve never heard any of the men complain, most just chuckle and go about their business. We aren’t looking at dicks any more than anyone else is, we just want to pee!
I did this at work once when I was pregnant too, very visibly. The women’s washroom had a pipe leak and was being repaired. I had a choice of going up or down a flight of stairs, or just going into the men’s room. I chose the latter. A colleague was in there washing his hands, and I got a bemused “uhhh…?” from him, to which I just said “pregnant!” which he accepted as an explanation. Got a couple of laughs crossing other guys on the way out too, but they were all very understanding.
I lived on the third floor of a three floor dorm in college. There was an elevator but it was very slow and it was faster to use the steps. My floor was co-ed but the others were male (1st fl.) and female (2nd fl.). For whatever reason, I took the steps only to the second floor and, needing to pee, walked directly into the communal womens’ bathroom. Fortunately, there was no one in there but the toilets were of a different type and there was some other slight difference that I don’t remember. I was completely bewildered for several seconds. I can’t even describe the feeling. Reality had been turned on its head. I turned around and walked out. IIRC, it was seeing a 200 room number on a door that made me realize what happened. I suffered a fairly serious head injury in a car crash a couple of months prior and I blamed it on that. I mean, I couldn’t be that dumb right? That’s my story and I’m sticking to it.
Edit: To be clear, on my floor there were separate male and female bathrooms…
Once by mistake. “That’s odd, there are no urinals”
Once or twice on purpose. The men’s room was closed.
Huh. I’ve used restrooms in places where they were all Any Gender. They never smelled any different to me than women’s johns. And I’ve used the men’s room when the women’s was unusable, ditto. For that matter, bathrooms in most people’s houses are used by everybody, and I don’t remember anybody complaining that they can tell by the stink that A Man was just in there. (A particular man, occasionally. But not A Man (in general.)
Same, on all counts.
My sister worked in a place where they decided not to turn some of the single-person restrooms into unisex restrooms because there was one man who worked there who peed on the seats.
But I’ve been in restrooms where a woman hovered and sprayed, which is equally gross. And on bad days, a ladies room might smell of stale blood, which is different from a men’s room, but worse. (And clean ones usually don’t smell much of blood.)
When i have accidentally wandered into men’s rooms, it was definitely the visuals (men washing their hands, urinals) that sent me out, not the odor. And i am generally very sensitive to ambient odors.