"Young men living in a Nairobi slum formally named Korogocho (but called Dirt Island because of a new paved circular road around the slum) who once were criminals are now becoming "biker boys". Biker Boys are essentially motor cycle taxis. This form of transportation is ideal in several ways, the narrow bikes can more easily fit the tight passages found in the slums, they are very fuel efficient (keeping profit margins higher for taxi operators) and they are fast. Though at first slum residents were hesitant to use these motorcycle taxi services once they began to see the advantages it became a very common practice to the point that today even businessmen and civil servants use the taxis. "

       Via: Survival Kit Blue 2