Traditional stop signs became too boring. When you sit in your car and have to stare all the time in very same signs all the day you just want to see something other.
So, some people took things in their hands and started to ‘decorate’ stop signs.
Now, here you can see plenty of photos of signs that were too boring but now they’re pretty funny and it is easier now to keep eyes on them 
photos:// Click Images for Sources
at 4:57 pm
Nice signs – don’t see many of them around my way but always gives a chuckle. Thought you might also like some of these :
http://www.evilmunky.com/2010/01/funny-graffiti/
at 7:08 pm
The ones that are obviously photoshopped are a kill-buzz, but some of them are still good. For me the fun is that something could have happened in real life, not the gag.
at 8:33 am
in quebec, stop signs are naturally in French: “Arret”. Clever people sometimes paint over the first ‘R’ and the ‘e’ so that..
ARRET –> A_R_T
I’ve seen it many times! Too bad I can’t find a picture of it
http://www.province-quebec.com/photos/diverses/arret.php