Every other time I see a "wet floor" sign the following idea comes to my mind. That sign forces me through unnecessary mental effort to deduce that wet floors can be slippery.
I think it's like providing a set of differential equations that describe slippery floors and expecting that everyone recognizes them and deduces that there's danger of falling. The sign actually means "man, the floor is slippery, you can fall and break apart" and IMO it could just read "slippery floor" instead.
Is there any reason why those signs use "wet floor" phrasing?
Best Answer
Here are several reasons why:
Slippery floors could be hazardous, but not all slippery floors are wet, and wet floors could be hazardous in other ways besides causing slippage. Thus, "Wet Floor" is a better caution than "Slippery Floor".
"Wet Floor" is easier to translate into other languages than "Slippery Floor".
Conciseness is desired in signage; wet is shorter and more direct than slippery
"Wet Floor" is idiomatic; "Slippery Floor" isn't so much.