As children across Canada return to class this fall, the safety advocacy group Preventable.ca hopes a combination of Renaissance art techniques and graphical engineering can spread awareness about safe driving in school zones. The medium for their message: an optical illusion that forces drivers to slow by appearing to be a small child playing in the street.

Preventable.ca, in conjunction with the ad agency Wasserman and Partners, has laid the above sticker across 22nd Street, in Western Vancouver, British Columbia. The image was mathematically distorted to appear as a child only at the distance of 100 feet. Any closer or farther, and drivers will only see a stretched out blob.

"There’s no distortion on the width, just on the length," said Liam Greenlaw, a creative director at Wasserman and Partners who worked on the campaign. "As you drive towards it, it slowly appears to raise from the road. From the optimal distance of 100 feet, it looks real, but as soon as you get closer, you can tell it’s an illusion."

The sticker is made from 3-M concrete sidewalk vinyl, and stretches for 40 feet. Because of the distortion, the head of the child is 400 percent larger than the feet. Greenlaw was inspired by advertising he had seen in malls, as well as European street art, that took advantage of this kind of distortion.

Called anamorphosis, distorting an image so that it only appears in proportion when viewed from a particular distance or angle dates back at least as far as the 15th Century. No less of a mind than Leonardo di Vinci is credited with producing the first anamorphic image in Western art.

Preventable.ca will leave the sticker on the road for a couple of weeks, but the sticker can stay on the road for between three to six months before environmental wear and tear degrades the image past the point of usefulness, Greenlaw said.

"It was a real exercise; half mathematics, half art,” he said.