It's a fairly common sign in parts of the US
that much I know.
(
mofaha ┐( ˘_˘)┌ ʅ(́◡◝)ʃ,
Thu 30 Jun 2011, 22:33,
archived)
It means "Be careful. The bridges will ice up before the roads do." in idiotic english.
(
Mu Dinofiddler,
Thu 30 Jun 2011, 22:36,
archived)
Or
It's a message from the evil voice that lives inside Jeff Bridges' head, instructing him to take crystal meth before driving
(
Cassius Kray floats like a butterfly, stings like a trout,
Thu 30 Jun 2011, 22:46,
archived)