People on motor bikes celebrate American President Barack Obama's visit to Kenya by holding up a photo, center top, of the president and First Lady Michelle Obama in Kisumu, Kenya, Saturday, July 25, 2015. President Barack Obama heralded Africa as a continent “on the move” Saturday as he opened a U.S.-sponsored business summit in Kenya, the East African nation where he has deep family ties. (Photo by AP Photo)

A motorized three-wheeled taxi carrying Muslim students drives past the Starbucks cafe where Thursday's attack occurred in Jakarta, Indonesia, on Friday, January 15, 2016. A day after attackers detonated bombs and engaged in gunbattles with police in the central part of Indonesia's capital, Jakarta tried to get itself back on track. (Photo by Dita Alangkara/AP Photo)

A garbage collector, with his horse and cart, prepares to unload rubbish at the municipal dump in Nezahualcoyotl, on the outskirts of Mexico City, February 18, 2015. Hundreds of horse or donkey-drawn carts will disappear from the streets of a municipality in the state of Mexico, located on the outskirts of Mexico City, and will be replaced by motorized vehicles, local authorities said. (Photo by Henry Romero/Reuters)

Leaves and forest foliage claim abandoned motors at makeshift car graveyards. German photographer Dieter Klein travels the world to find vintage automobiles left to rust in leafy forests and fields. Here: Seemingly camouflaged cars are stacked on top of each other causing them to blend in with the landscape, in 2013, France. (Photo by Dieter Klein/Barcroft Media)

A picture composed by the French street artist JR is plastered to a wall under a highway as part of a community project called “Through A Mother's Eyes”, which involves members of the economically distressed neighborhood of Hunts Point in images taken by and of themselves on June 30, 2011 in New York City. JR, a recent TED prize winner, has staged similar projects around the world that look to transform high crime and impoverished neighborhoods into spaces for street art combined with the celebration of community. (Photo by Spencer Platt/Getty Images)

A Fulton Hotshot lights a controlled burn on the so-called “Rough Fire” in the Sequoia National Forest, California, August 21, 2015. In California, suffering its worst drought on record, about 2,500 people were forced to flee Christian camps east of Fresno at Hume Lake as the so-called Rough Fire crossed Highway 180, officials said. (Photo by Max Whittaker/Reuters)

The car of Dan Wheldon of England driver of the #77 Bowers & Wilkins Sam Schmidt Motorsports Dallara Honda (left) flies in the air during the Las Vegas Indy 300 part of the IZOD IndyCar World Championships presented by Honda on October 16, 2011 at the Las Vegas Motor Speedway in Las Vegas, Nevada. (Photo by Robert Laberge/Getty Images)