Riders for Health is a charity that ensures healthcare workers can reach African villages on a regular basis by supplying them with motorcycles and pick-ups and, crucially, ensuring that they work. According to the article I read, they do this by operating,a system of preventive maintenance that would shame any British rail operator. Spark plugs are changed before they stop sparking. Cylinders are re-bored before they seize up. Money permitting, vehicles are replaced before they break down unexpectedly, and no health worker climbs onto his or her...