Why do signs read "wet floor", not "slippery floor"?
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?
Solution 1:
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.
Solution 2:
The sign says "wet floor" because the floor is wet.
The sign is giving you full and complete information about a condition of the floor that is not its normal state. Wet floors are not always slippery; slippery floors are not always wet.
Some people might be more concerned about getting their pants wet when splashing through the water; should the sign say "splashy floor" for them? Or "shoe-shrinking floor" if they're more concerned about their nice leather wingtips? "Foot-discomforting floor" if they're wearing thin sandals that can be soaked through in one step?
The sign gives you all the information you need to take whatever action you deem appropriate for dealing with the situation.
Solution 3:
Also, since "wet" is much shorter, it can be written in larger letters and consequently seen from further away.
Solution 4:
I think the reason is more people in the world understand the meaning of "wet" than "slippery". Its short and easier for non native speakers (perhaps there may be kids who understand wet but not slippery). Summary: Wet is shorter and easier than slippery.
Solution 5:
'wet floor' is a cautionary notification & serves the purpose of alerting people, whereas 'slippery floor' sounds more 'panicky' and might induce unnecessary anxiety. Its all about conveying the message in a relatively 'comforting' way.