Leonard Segel, Professor Emeritus of Mechanical Engineering at the University of Michigan, died on 15 February 2012 in Ann Arbor, Michigan, at the age of 89. Professor Segel was involved in the origination of the International Association of Vehicle System Dynamics, a long time President and Board Member of the Association, and an active contributor to the field of vehicle dynamics and renowned for his leadership, intellectual rigour, and integrity. Professor Segel's early work in applying the linearised aircraft equations of motion to the automobile and ground vehicles helped to spur and dramatically advance the analysis and computation of the motion and behaviour of ground-based motor vehicles.
Professor Segel was born in Cincinnati, Ohio, and served in the Second World War with the US Navy. He received his BS in aeronautical engineering from the University of Cincinnati and an MS in mechanical engineering from the State University of New York at Buffalo. From 1947 to 1966 he worked as a research engineer at Cornell Aeronautical Laboratory in Buffalo. He joined the engineering faculty of the University of Michigan in 1967 and as a research engineer at the Highway Safety Research Institute (later to become the Transportation Research Institute), where he was Head of the Physical Factors Division. His leadership helped develop the Institute into an important centre of research in the areas of automotive stability and control, tyre mechanics, driver–vehicle interactions, and the vehicle/road interface.
Professor Segel's publications and lectures in these areas brought him international recognition, resulting in numerous honours and invitations to speak, consult, and serve on industry and government task forces and commissions. As a visiting professor, he taught in Israel, China, Australia, and Japan.
Colleagues of Professor Segel remember him with fondness as a ‘gentle taskmaster’ who relished a difficult problem, demanded rigorous thinking, loved arguing different perspectives, was intellectually curious, and always sought a truthful evaluation based on sound analysis and accurate experimental substantiation. These personal and professional attributes have subsequently helped shape and direct many colleagues or collaborators of Professor Segel and, thereby, the quality and integrity of their subsequent vehicle dynamics research as well. For these reasons, as well as all of Leonard's scholarly contributions, members of the vehicle dynamics community are not only respectful, but grateful.