Of course they are necessary at large public events, but nobody likes the sight and smell of great banks of port-a-potties. The 2P Portable Restroom concept aims to reduce the numbers of rented cubicles for the sake of freeing up a bit of field, cutting costs and decreasing wait times for available washrooms.
Kevin Cheng's Red Dot Design Award entry can perform as suggested above by permitting two people to use each stall at the same time. The idea may at first sound awkward and off-putting, but the spatial solution is really quite clever.
Each 2P Portable Restroom incorporates an open urinal on the external back wall. When installed in rows, the Johnny-on-the-spots create a screen for men's privacy when emptying their bladders.