As chief historian for USAC and the Indianapolis Motor Speedway, Davidson has written, or contributed to numerous books about auto racing and the Indianapolis 500. His earlier contributions include the annual 500 Yearbooks and magazine articles. In 1974 and 1975, he wrote a short-lived series of Indianapolis 500 annuals entitled "Donald Davidson's 500 Annuals." During the month of May for numerous years, Davidson penned a daily column in the "Indianapolis Star" about Indianapolis 500 history. In addition to his work on the radio Davidson also co-hosted local Indy 500 practice and qualifications coverage on WTTV (1984–1989) and WNDY-TV (1995–1997).