This Tricky Crosswalk Stops Drivers With an Optical Illusion by Liz Stinson from on 2016-04-25 14:00 (#1BQ8B) From the side, the markings appear to be flat, but from a certain vantage point, they take on a 3-D appearance like a set of roadblocks. The post This Tricky Crosswalk Stops Drivers With an Optical Illusion appeared first on WIRED.