Excuse me, but your slip is showing!

I don't know how this issue has escaped me for nearly forty years, but I'm not alone. In that time, I have occasionally talked about coefficient of friction for floors, but I just discovered there has been no widely accepted standard for slip resistance. Not only that, but neither the IBC nor ADA define slip resistance, even though both require slip resistant floors and walkways.

How the heck is that possible? Think of all the very specific requirements in the building code. How did they miss this one? And think of ADA, with its Byzantine combination of Spock-like precision in some areas, and a "Take a guess and we'll see you in court" approach to other requirements. How can it be that the good folks who write the ADA requirements know exactly what so many dimensions must be, but they have no idea what they mean by slip-resistant? It seems to me that not falling on your arse is a lot more important than a quarter inch difference in the location of a water closet, but this apparently - no, this obviously important performance characteristic has had no definition.