I posted this picture over the weekend on my own Facebook page. And I have several friends, who actually are surveyors and pilots.

So, apparently, these are used by pilots and surveyors as part of their mapping.

My favorite comment was "This is what Wiley Coyote painted on the road so, he could lure the Roadrunner here and drop an anvil on his head".

I'm looking for some more funny ones.