When I was in high school, the city added large speed bumps to the street in front of the junior high school. These speed bumps were large and had big yellow stripes on them.
The week the bumps went in, my friend and I had a riot of a time watching people ignore the large yellow "SLOW: SPEED BUMPS AHEAD" signs. Totally oblivious, or thinking that the bumps were smaller than they were, people didn't slow down and they would end up launching their cars into the air before coming down with a slam. ehehehehehehehe ....
.....Kelly