In 15 cities in China, pedestrian crossings turn green as soon as pedestrians step onto them.3 photos

For the Chinese Environmental Protection Fund, DDB China Group created a truly “green” pedestrian crossing—an innovative form of social advertising aimed at reducing the popularity of cars in Chinese cities. This pedestrian crossing clearly demonstrates the advantages of walking: the more people use it, the greener the tree depicted on it becomes. Specifically, green paint has been applied in front of the crossing; when pedestrians walk across it, their footprints leave green marks on the leaves of the “tree.” There’s no need to worry, as this paint does not stain shoes at all.