Seen on the West Seattle Bridge yesterday (a photo would be great but where to stand and take it?):
Signposted: slippery pavement (the universal “car with wavy wheel track behind it” symbol. And right there by the sign, a pair of actual wavy skidmarks as some car hit the barrier. No idea if they went over the side or not, but hey, they can’t say they weren’t warned. And now they can serve as an example for others.