In the summer of 2021, Western Resource Advocates (WRA) commissioned GridLab and Evolved Energy Research for a joint study to investigate the role of transportation electrification in economy-wide decarbonization for the state of Arizona. As of early 2022, Arizona still lacks significant binding clean energy goals or transportation decarbonization measures. This study analyzes various pathways to decarbonizing Arizona’s economy by 2050 and meeting emission reduction goals set out by the International Panel on Climate Change (IPCC), with a particular focus on the relative costs of different decarbonization strategies in Arizona’s transportation sector. The study also examines least-cost pathways to reduce carbon emissions from other sectors, including the power sector, in achieving economy-wide decarbonization.