Optical illusion helps create fake speed bumps - CNN.com: PHILADELPHIA, Pennsylvania (AP) -- Cathy Campbell did a double-take and tapped the brakes when she spotted what appeared to be a pointy-edged box lying in the road just ahead.She got fooled.It was a fake speed bump, a flat piece of blue, white and orange plastic that is designed to look like a 3-D pyramid from afar when applied to the pavement.The optical illusion is one of ...