To encourage everyone to walk more and drive less, the China Environmental Protection Foundation created ‘Green’ pedestrian crossings using canvasses and ink pads. Giant white canvasses with a bare tree were placed across 132 crosswalks in 15 cities, and as pedestrian crossed, their shoe soles, imprinted with a small amount of green paint, left behind a trail of leaf-like footprints. Almost 4m people passed through the installations, and the final posters were eventually hung in several urban locations.