A couple walks and a man rides his bicycle during the Day Without Cars under the slogan "Turn off the engine, turn on your heart", (in Spanish  Apaga el motor, enciende tu corazon),  in Medellin, Antioquia department, Colombia on April 22, 2014. A municipal decree prohibits the use of private cars today, in an attempt to reduce pollution levels and to promote the use of public and alternative transports. AFP PHOTO/Raul ARBOLEDA        (Photo credit should read RAUL ARBOLEDA/AFP/Getty Images)