D. from Harvard University. For most of his career, he worked for the Insurance Institute for Highway Safety, retiring as Chief Scientist in 2004. Since that time he has conducted research independently and consulted for several organizations, and has published more than 350 articles in professional journals and lectured around the world on topics including occupant restraints, alcohol-impaired driving, and young drivers. He is ranked by the Institute for Scientific Information as one of the most highly cited authors in his field.