One reason for the confusion is that few studies have looked at how drivers react to novel crosswalk designs. Even some that have been done are inconclusive. Oklahoma transportation engineers, for example, studied the effects of a crosswalk painted to appear in 3D, meant to improve safety at a crossing near a school. The design gave drivers the illusion that the stripes were actually raised blocks. The engineers found that many motorists did slow down when they saw the markings, at least at first. But they also found that a significant number of motorists swerved to avoid them, replacing one dangerous behavior with another. “Additional study is needed to determine if installing a 3D crosswalk diminishes or enhances pedestrian safety,” the researchers concluded in 2018.