this is actually an interesting problem for building designers, because the "fair" scenario of equal space for each ends up in too few female restrooms (assuming a natural split of clientele) because the men get urinals which can be packed in like sardines, the women don't.

Even if you go "fair" and have the same number of drains regardless of size you often end up with lines for the women.

Most large place compensate by putting in way too many toilets on average or just hope there isn't a crush-time.

The best place to see this in action is at a stadium with 50/50 fans during half-time or other break.