This paper examines the relationship between traffic fatalities and income for vehicle occupants and pedestrians and investigates factors underlying the decline in fatalities per vehicle kilometre travelled (VKT) using panel data for 32 countries from 1963-2002. Results suggest the downward-sloping portion of the curve relating traffic fatalities per capita to per capita income is due primarily to improved pedestrian safety (Kopits and Cropper, 2005a). More detailed models shed light on factors influencing pedestrian fatalities/VKT but some of the long-term improvement remains unexplained. Declines in occupant fatalities/VKT are explained primarily by reductions in alcohol abuse, improved medical services, and fewer young drivers.