The Multimodal Planning Division (MPD) of the Arizona Department of Transportation has been tasked with identifying corridors throughout the state where improvements to the transportation infrastructure supports the greatest potential commercial and economic benefits. These "Key Commerce Corridors" represent a strategic statewide approach to leverage infrastructure improvements to enhance Arizona's competitive economic position. This document presents the basis for the identification and evaluation of the Key Commerce Corridors.

Unlike the rest of the Phoenix metropolitan area, population density in central Phoenix dropped during the 1970s and 1980s. The primary cause was a decrease in the number of housing units. Rising vacancy rates contributed, but the increase in vacancy rates was similar to that of the entire metropolitan area. Between 1990 and 1995, population density rose in central Phoenix. A sharp decline in vacancy rates was a major factor in the turnaround, though the vacancy rate decline only matched that of the entire metro area. Another major factor in the increase in density was the rising number of people residing in prisons, homeless shelters, or on the streets.

The condition of Arizona’s infrastructure has a direct impact on economic productivity and quality of life. As economic competition expands domestically and globally, and as the knowledge economy evolves, the importance of a strong infrastructure increases. Education, in particular, is of growing importance. Arizona’s infrastructure challenges will require commitment and creativity to meet the needs and potential of 10 million people and to ensure a positive future for the state.