The Indian transport ministry is experimenting with 3D paintings on highways to make motorists slow down.

Kelly Grovier looks at the history of artworks that confuse our eyes.
By Kelly Grovier. 29 April 2016
Does painting still have the power to stop us in our tracks, let alone save our lives? India’s transport ministry is counting on it. Photos floating through social media this week have delighted in the experimental use of optical tricks in the painting of crosswalks in India. From the point of view of drivers approaching these pedestrian crossings, the flat white zebra stripes that our eyes are accustomed to seeing suddenly appear to levitate like weightless rafters in space.
Road in Pujiang county, China (Credit: Feature China/Barcroft Media via Getty Images)
The Indian Transport ministry is trialling optical tricks in crosswalks – similar to this one in Pujiang county, China (Credit: Feature China/Barcroft Media via Getty Images)
By mesmerising motorists with the arresting 3D technique, civic planners are hoping to reduce the number of accidents caused by speeding. In doing so, they have tapped into an intriguing artistic tradition and, in particular, the power of a 16th Century masterpiece that was likewise conceived at the intersection of optical illusion and mortal salvation.
India’s Union Transport Minister Nitin Gadkari's tweet (Credit: Nitin Gadkari/Twitter)
India’s Union Transport Minister Nitin Gadkari tweeted this image on 26 April: “We are trying out 3D paintings used as virtual speed breakers” (Credit: Nitin Gadkari/Twitter)
When it was unveiled in 1533, the double portrait The Ambassadors by the German and Swiss artist Hans Holbein the Younger must have struck observers as a road-bump for the soul. Looked at straight-on from the front, the huge oil-on-oak painting is enigmatic enough, presenting to the observer a pair of distinguished diplomats caught in a clutter of worldly amusements: musical instruments and scientific whatnots scattered about the shelves on which they lean.
The Ambassadors (1533) by Hans Holbein the Younger (Credit: Wikimedia Commons)
The Ambassadors (1533) by Hans Holbein the Younger contains a macabre surprise that jumps out from the shadows (Credit: Wikimedia Commons)
But pass by the painting at a shallow angle from the left, such that your eye catches the work by chance in the periphery of its vision, and a mystery tucked into the centre of the painting stops you cold. Only from that askance vantage do you see the optical illusion Holbein has secretly positioned into the foreground of his work: the cracked cranium of a spooky skull grinning back you. Holbein’s twisted skull is a version of the traditional artistic device of the momento mori (or “remember you must die”), used by painters and sculptors to elevate their works into spiritually teachable moments that remind observers that this world is transitory and that they must live virtuously and seek salvation.
The distorted skull in the middle of The Ambassadors (Credit: Wikimedia Commons)
The distorted skull in the middle of The Ambassadors is a visual puzzle for the viewer (Credit: Wikimedia Commons)
Perhaps concerned that observers had become too accustomed to seeing skulls in Medieval paintings and that their religious impact had become fatigued, Holbein appears to have upped the ante on the memento mori by transforming the device into a macabre surprise that jumps out from the shadows. Like the 3D stripes in the crosswalks in India, the skull is an example of artistic “anamorphosis”. It’s just an illegible blur when seen from any other angle than the surprising one from which Holbein hopes he’ll trip you up.
Once seen for what it is, the skull overshadows the worldly significance of the symbols of cultural refinement that surround Jean de Dinteville, the French ambassador to London (on the left), and his companion, the papal diplomat Georges de Selve, the Bishop of Lavaur (on the right). In the distended light of Holbein’s elastic skull, the soul slams on its brakes and yields to the path that leads from this world to the next. http://www.bbc.com/culture/story/20160429-how-optical-illusions-can-save-lives