Describes the evolution of transportation routes and transportation methods in Pima County throughout time, and the effect that modes of transportation have had on the size and form of the community. Stage, freight, and railroad transportation followed the main historic corridors established by previous cultures and technologies.

Sun Corridor: A Competitive Mindset builds upon the 2008 Megapolitan report by looking at present and future prospects for the Sun Corridor, the economic heart of Arizona stretching along Interstate 10 from Phoenix to Tucson, down Interstate 19 to the Mexican border.