On a busy street near a school in London, a newly painted crosswalk is designed to slow down drivers through an optical illusion: As someone approaches, each white stripe on the road looks like a three-dimensional block. The idea is that by catching the eye, the optical illusion will force drivers to concentrate more on the road rather than being distracted by other things.
London took inspiration from similar crosswalks in India and Iceland, which have thus far been successful. For the coming months, the city council will be monitoring the crossing with a camera to see how drivers react; one concern was that it would be so realistic that drivers might swerve to try to avoid the imaginary bumps, though there has been no evidence of that so far.
The government also wants to see what happens over time as local drivers become accustomed to the crossing; drivers who are new to the area, presumably, will continue to drive more cautiously because of the intervention. Should it work, we might start seeing more optical illusions on streets around the world.