You know those optical illusions where you have to stand in the right spot to properly see them?
Such as….

Now what if you put that spot right in the middle of a busy crosswalk?
You create one of these illusions with the outside of nearby buildings, wait for people to catch it in their eye while they cross the crosswalk, stop to look, and get hit by a car. You compete against another person who has placed a moron trap in another spot. Whoever gets the most hits wins.