Concerned about the costs of operating speed cameras to slow down drivers, the U.K.’s Norfolk City Council turned to a cheaper visual illusion courtesy of trees planted in the shape of a funnel.
The planting of trees and hedges is designed to reduce speed “by playing with the driver’s peripheral vision”. One technique involved placing trees – at decreasing distances apart – on the approach to a village, tricking drivers into thinking they were speeding. “If you are staying at a constant speed, your peripheral vision [which takes in the trees] is giving you the impression you are going faster,” explained Mr Hallett. “People hit the brakes before they hit the village.”
Another method was to plant trees “so that it looks like the environment is closing in on the driver”, he added. The road remains the same width but trees are planted on a “lazy diagonal” that gets narrower towards the entrance to the village.
Preliminary results indicate speeds could be cut by 2-3 miles per hour. Keep in mind that the trees planted are still saplings. It could take as much as 10 years for full effects to be measured.
The BBC has video of the trees.