My school did this exact same thing. They thought it would somehow combat the epidemic of teens smoking in the bathroom, so they put iron prison bars on all but 1 bathroom. So between classes, I had 5 minutes to sprint all the way across the school, use the bathroom, then sprint all the way back to my next class.
And when I got to that one bathroom it was so full of cigarette smoke I nearly collapsed of emphysema.
Hail Eris.