Thomas H. MacDonald was born in 1881 and was a pioneer in the use of traffic needs as a basis for system planning and road classification. He also excelled in applying scientific methods to traffic movement and safety studies.
A few years after the turn of the century he became Chief Engineer for the Iowa State Highway Commission and in 1919 was appointed Chief of the US Bureau of Public Roads, a position he served in for 34 years. He retired from the federal government in 1953 and was made a Distinguished Research Engineer and professor at Texas A&M University. He earned a Bachelor in Civil Engineering Degree from Iowa State University and was awarded honorary Doctor of Engineering Degrees from Brooklyn Polytechnic Institute and Iowa State University. Other awards during his very productive lifetime included being recipient of the Presidential Medal of Merit and the David Beecroft Memorial Award.