A recent post in our blog discussed NY City’s decision to require more restroom capacity for women than men. Several possible reasons were proposed, including that women may require more processing time on average. Turns out there is data on this. In one study women required nearly three minutes while men required on average 83 seconds (about 1/2 the time of women). See …
and a Feb 24, 1994, Wall Street Journal article titled “Potty Parity’ Lets Women Wash Hands Of Long Loo Lines — Several State Laws Give Jane As Many Johns as John”
The WSJ article is also interesting because it mentions that some architects are designing restrooms with movable walls. This allows them to adjust capacity depending on known demand fluctuations, i.e., flexible capacity for flushes.
It would still be interesting to have some data on the variability of processing times across the sexes. With mean and variance data, one could get an estimate of how much more female capacity is needed to equate average waiting times. (Of course, other objectives are possible, such as equating the probability that each will be “served” within 5 minutes, or whatever threshold is deemed to be appropriate.)