Boda-boda is a motorcycle taxi, originating in East Africa (from English border-border).
The boda-boda taxis are part of the African bicycle culture; they started in the 1960s and 1970s and are still spreading from their origin on the Kenya-Uganda border to other regions.
The name originated from a need to transport people across the "no-mans-land" between the border posts without the paperwork involved with using motor vehicles crossing the international border.
This started in the southern border crossing town of Busia (Kenya/Uganda), where there is over half a mile between the gates, and quickly spread to the northern border town of Malaba (Kenya).
The bicycle owners would shout out boda-boda (border-to-border) to potential customers.
It is not unusual to see four adults to a single motorbike.
Reference: Wikipedia