The interest of public health professionals in motor vehicle trauma has in creased in recent years. This interest is almost entirely the result of seeds planted by William Haddon, Jr., whose memorial service I attended two days before beginning this chapter in March, 1985. In addition to originating much of the conceptual framework for the field and a considerable body of empirical research, Haddon also provided much of the funding for the more distinguished work of investigators in the 1970s and early 1980s through the good offices of the Insurance Institute for Highway Safety. The federal safety standards for motor vehicles, most of which Haddon wrote with Robert Brenner in 1968-1969 when Haddon was head of what is now the National Highway Traffic Safety Administration, had by 1982 saved something on the order of 100,000 persons from premature death (68). Therefore, the story of the public health approach to motor vehicle trauma is, in large part, a memorial to William Haddon, Jf. Haddon gave credit to his intellectual predecessors, such as Hugh DeHaven and John Stapp. It was DeHaven (13) who, in the 1940s, investigated the ability of human beings to survive mechanical energy insults. Stapp (77) demonstrated first with animals, and then with human volunteers, including himself, that human beings could tolerate up to 40 times gravity in deceleration forces without injury if those forces were distributed over a sufficient area of the body.