The state or condition of having an equal or appropriate number of restrooms for each sex.
Technically, there's already more than gender equity or "potty parity," as it is sometimes called at work. For more than a decade, the code has specified that women's toilets outnumber men's toilets (not including urinals) in large assembly areas at, roughly, a 3-2 ratio.
For most women, however, the issue is not getting as many bathrooms as men it is about getting more. Women simply take longer in the bathroom and it's not because they're primping.
A 1988 study of the bathroom habits of men and women at four public venues revealed that women took 55% to 65% longer in public bathrooms than men. The wait is for the stalls, not the mirror.
Carla Hall, "Is Potty Parity Just a Pipe Dream?," The Los Angeles Times, January 14, 2001
The so-called potty parity bill, by Sen. Art Torres (D-Los Angeles), would require all new or remodeled sports or entertainment facilities, both public and private, to be equipped with the minimum number of toilets recommended by the state's uniform plumbing code. Torres said he was inspired to author the bill when his wife, Yolanda Nava, got stuck behind 56 other women waiting to use the restroom at the Ahmanson Theater in Los Angeles. Several of the women who could wait no longer banded together and raided a nearly deserted men's restroom nearby.
"Women's Restroom Bill Signed," UPI, September 18, 1987
When I'm reading and I come across a word or phrase that I haven't seen before, a little bell goes off in my head (at least I think it's only in my head) and I immediately think, "Oooh, a potential Word Spy word!" Frustratingly often, however, I'll research the word and discover not only that it's old, but that it's also extremely popular with hundreds of citations showing up on my searches. "Boy, I sure missed the boat on that one," I'll say to myself (at least I think I say it to myself) and move on as a sadder but wiser man.
Occasionally, however, one of these older and popular words is just too irresistible to pass up. This is particularly true if it's an alliterative phrase, because (as anyone who has read any of my books will tell you), I'm a helpless sucker for alliteration. Hence, you get "potty parity" foisted upon you today, despite its apparent popularity (yup, I missed it) and its relative antiquity.