Regional System Performance

Regional Mobility & Congestion

Despite being the 11th largest metropolitan statistical area in the U.S., Tom Tom Travel Index data lists Phoenix as the 42nd most congested city for 2020. That puts the level of congestion in Phoenix below cities such as Providence, Albuquerque, and Tucson. Nevertheless, the MAG region still experiences congestion, particularly during peak periods. Congestion affects the movement of goods and people, and has environmental impacts due to increased fuel consumption. Annually, Texas A&M University Transportation Institute, a nationwide leader in assessing the impacts of congestion, estimates that congestion costs the region $3.3 billion.

As Chart 8 shows, Arizona’s population has been steadily growing along with VMT. This trend is expected to continue and will place further stress on our transportation system. This will lead to increased congestion should mitigation efforts be unable to keep pace. 

chart showing population in the MAG region increasing
Vehicle Miles Traveled & Population, 2000-2019. Source: ADOT HPMS & MAG Travel Demand Model

MAG uses several data sources to examine congestion in the region across a variety of facilities. For the purposes of performance measurement, congestion is defined as a ratio of the measured speed divided by the speed limit for each stretch of roadway in the network. The data is further broken down by time periods.