I'm a female, so I always wait in line to use the bathroom.

(all talking)

Ahhh.

(crickets)

For a typical busy bathroom, women have to wait about 34 times as long as men.

But, contrary to some stereotypes, it's not because they're busy chitchatting or reapplying their makeup inside.

So then why is there always a line for the women's restroom?

Women spend as much as twice as long in the bathroom as men, and that's because they menstruate, they have more layers of clothes to remove, they always have to enter a stall.

And they're far more likely to have kids or elderly people with them.

But these are just contributing factors to a much larger problem.

Well, in most of the building stock, there are fewer fixtures for women than there are for men.

That's Kathryn Anthony, a professor of architecture at the University of Illinois at Urbana-Champaign.

It is definitely a subtle, but very powerful, form of gender discrimination.

No question about that, it is plain and simple.

There's no disguising it.

She says that in many buildings, the men's and women's rooms are the same size, but because urinals take up less space, men's rooms have more toilets, which contributes to less waiting time for men.

To figure out just how much less, queuing theorists at Ghent University developed a model.

First, they considered bathrooms that were the same size where men have 12 toilets and women have just 10.

Then, they accounted for the time spent per bathroom visit for women and men and the speed of traffic.

The model showed that if someone arrives every five seconds, on average, women will wait more than six minutes while men will wait just 11 seconds.

So then what would a better toilet ratio be?

I would say the ratio should be well more than 1 to 1.

She's right.

According to this model, the women's room should have at least 50% more toilets than the men's room, as they show here.

Only then would men and women have nearly equal wait times.

Now, the US is getting closer to this target thanks to the so-called "potty parity" movement.

It took off in 1987 when a California state senator went to a Tchaikovsky concert at the Hollywood Bowl.

There, he waited for more than half an hour for his wife to use the bathroom.

He realized just how long it took for her, and that was unfair.

She complained, and he complained and said, "wait a minute, this isn't right."

Soon after, he introduced a bill to the California Senate, which demanded more toilets for women in large, new public buildings.

That started a wave of legislation across some states and also cities and municipalities.

At least 21 states and several cities have since passed potty-parity policies.

In 2005, for example, New York City passed legislation that requires a 2-to-1 toilet ratio in places of public assembly, such as baseball stadiums.

But here's the thing: Even where these laws exist, you still find long lines for the women's room.

And that's because they apply only to buildings that are new or undergoing major renovations, which leaves thousands of older buildings, such as theaters, with too few toilets for women.

Sure, it's a hassle to wait, but that's not the only problem.

Long term, it can actually affect your health.

A lot of women can end up with urinary tract infections and other kinds of health issues.

So, what can be done?

Aside from waiting for renovations or new construction, there's a new trend: gender-neutral bathrooms.

That's a way to alleviate the problem of potty parity altogether, so either nobody waits or everybody waits, but you don't have one group waiting more than another.

And let's be real.

Women are already using the men's room.

If the line in the women's room is too long, I will never hesitate to go to the men's room.

I probably go to the men's room a couple times a year when it's a dire situation.

I will literally go in the men's bathroom probably more than I will go in the women's bathroom in New York.

I also use the men's room a lot when I'm waiting.

Because, well, we all know the alternative is a lot worse.