I grew up on a street with a sign that read "SLOW CHILDREN AT PLAY." I'm still not sure if that was a comment on our intelligence or our athletic ability.
I also frequently see signs that say "DEAF CHILD AREA." I'm never quite sure what I'm supposed to do when I see this sign. Do I slow down? Or is it just supposed to make me feel bad that I have a perfectly good pair of ears? I don't see a reason I should have to go any slower than in any other residential area. I mean, it's not like they can't see me coming. They just can't hear me if I honk at them. I wonder what I would do if there was a deaf child in the middle of the road... I don't know the hand signal for "honking noise."
"SLIPPERY WHEN WET" is just a little too patronizing to even take serious. Sounds like something that should be in a children's book. A slow, deaf children's book. It's also not a very useful sign because it doesn't tell us if it's even wet now. How are we supposed to know if we should even worry about the slipperiness unless we know whether or not it's wet? That's like putting up a sign in Kansas that says "TORNADOES ARE DANGEROUS" and assuming that will keep everyone safe.
Speaking of slow children, the other day I was riding in the car with an unnamed relative who was driving quickly through some curving roads when we approached several people crossing ahead. They were carrying boxes and bags and heading across the street to a grassy park. They didn't seem to care about hurrying even as we quickly sped toward them. In fact, a couple of them stopped in the middle of the road and one turned back to join another who was lagging behind the group. My unnamed relative was frustrated as he put on his breaks and said, "What a bunch of ret—" and then was close enough to see that they all had Down Syndrome.
