Enrique Peñalosa, the former mayor of Bogotá, Colombia, sees things in a much simpler light: “God made us walking animals—pedestrians. As a fish needs to swim, a bird to fly, a deer to run, we need to walk, not in order to survive, but to be happy.”38 That thought is beautiful, perfectly obvious, and probably impossible to prove. But we do know that we need to be active in order to be healthy and that walking is the easiest way for most humans to be usefully active.
