Assessing the Consumption Costs of Motor Vehicles on Arizona Roads and Bridges

The Arizona Department of Transportation (ADOT) is responsible for building, operating, and maintaining the roads and bridges of the state highway system; the primary source of funding comes from fuel taxes. Arizona's last fuel tax increase was in 1991 ($0.18 gas/$0.26 diesel), and Arizona is one of the ten states with the lowest fuel tax rates. Meanwhile, electric vehicles (EVs) are becoming more common and weigh much more than passenger vehicles since EV batteries add substantial weight to the vehicle. What are the impacts of heavier and over-dimension/overweight (OD-OW) vehicles on Arizona’s transportation infrastructure compared to other vehicle classes? This research study will identify and document the current impact on Arizona’s roads and bridges by motor vehicles classified in the following three categories: passenger vehicles, commercial vehicles, and OD-OW vehicles. The study will determine the consumption costs (i.e., the costs to build, maintain, and repair the roads and bridges) for each vehicle category. Objectives: The primary objective of this research is to identify and document the impacts and the consumption costs to build, maintain, and repair damage from these four motor vehicle categories on the roads and bridges owned, operated, and maintained by ADOT.