The Arizona transportation history project was conceived in anticipation of Arizona’s centennial, which will be celebrated in 2012. Following approval of the Arizona Centennial Plan in 2007, the Arizona Department of Transportation recognized that the centennial celebration would present an opportunity to inform Arizonans of the crucial role that transportation has played in the growth and development of the state.

The report consists of a historical narrative and a series of topical essays. The seven-chapter historical narrative is a history of Arizona’s highways that extends from the pre-Columbian era to the present. The 14 topical essays extend the scope of the history beyond the state’s highway system. They include overviews of the development of other transportation modes (railroads, aviation, and urban transit), a brief history of highway pavements, a lighthearted look at the motoring experience during the 1920s and 1930s, and an exploration of how changes in transportation infrastructure affected some Arizona communities. The topical essays also provide additional historical information on bridges, urban freeways, the Interstate system, ADOT and its predecessor agencies, and famous roads such as U.S. Route 66, U.S. Route 89, the Black Canyon Highway, and the Beeline Highway.

The report also includes a timeline of transportation-related developments. This chronology not only provides an accessible overview of Arizona’s transportation history; it also places that history in a larger context by including transportation-related developments from the rest of the nation and around the world. Finally, the report contains a guide to archives in Arizona that hold significant collections of historical photographs related to the state’s transportation history, a bibliography of published historical sources related to the history of highways in Arizona, and a discussion of how the historical narrative and topical essays could be used to produce publications and media that would be made available to the public.