I wasn't aware this was even something people worried about until I saw someone else doing a low-tech version of it a while back... <a href="http://www.rgj.com/story/money/business/2014/02/19/-reno-inventor-peep-no-more/5600733/" rel="nofollow">http://www.rgj.com/story/money/business/2014/02/19/-reno-inv...</a>
<i>"Tooshlights can also collect data on restrooms’ usage rates: for example, a consistently green light in a sea of red may tip off the maintenance crew that a loo is out of order or needs to be cleaned."</i><p>This doesn't really clarify what happens with a stall that's out of order or in an, ahem, "unusable" state. In fact it sounds more confusing because now the person that was first wants to become first again and wait for another usable stall to open...