COMMON WORKPLACE ACCIDENT(?)

How many times have you done that thing where you're going into the bathroom at the exact same time someone else is coming out, and one of you almost knocks the other one out? I wonder if someone's tracking how many times that actually happens. The only solution I can think of would be to put a porthole in the door so you can see if anyone's coming, but my guess is that being able to look into a bathroom is not high on the list of requirements for a bathroom door.