Reminds me of the Cyburbian favorite:
The M-LAW’s annual Wacky Warning Label Contest: http://www.mlaw.org/wwl/
Why don't you knock it off with them negative waves?
Why don't you dig how beautiful it is out here?
Why don't you say something righteous and hopeful for a change?
From Kelly's Heroes (1970)
Are you sure you're not hurt ?
No. Just some parts wake up faster than others.
Broke parts take a little longer, though.
From Electric Horseman (1979)
Oh dear... I'm not sure if it's a photoshop or not but I guess it's the most likely, specially since the fonts of the US highways are available for it. But still it is quite funny, and potentially dangerous in the real world... Just imagine passing by that sign and laughing at it (but didn't catch the small print) and a second later going "Oh sh..." at the end of the bridge...
I think these are self explanitory!