A leader and innovator in the field of transportation, Thomas Deen has had a distinguished professional career highlighted by his commitment to excellence and pursuit of solutions to transportation problems. In 1956 he became the assistant city traffic engineer for Nashville, Tennessee, where he later served as the director of the Nashville Area Transportation Study. He joined the National Capital Transportation Agency in Washington, D.C., as Director of Planning in 1961. This agency was responsible for preparing the initial plans for construction of the Washington, D.C., rail transit system. He was a partner in the renowned planning firm of Alan M. Voorhees, a worldwide leader in urban transportation planning during the 1960s and 1970s. From 1980 until his retirement in 1994, Mr. Deen served as the Executive Director of the Transportation Research Board – the national transportation research organization and a division within the nonprofit National Research Council of the National Academies of Science and Engineering. He was the winner of the Theodore M. Matson award in 1995.