>>I wondered, I know below is real, it's usual even at highways in Turkey. But for Canada is it real?
>
>If this was for real, I guess it would work first fifty times, until everyone sort of knew where the stickers are. Then they'd just stop slowing down for those fake holes, until they start hitting real potholes at full speed. By which time the stickers would be worn out anyway.

It would be more dangerious. Some drivers would be run left with panic then would be cause traffic accidents...