Utah vehicle emissions drop 73% despite rising population and traffic

Utah has seen a 73% decrease in vehicle emissions since 2011, despite a 20% increase in population and a 30% rise in vehicle travel during the same period.

Officials attribute this decline to advances in vehicle design and cleaner fuel standards. Bryce Bird, director of the Utah Division of Air Quality, identified the adoption of Tier 3 gasoline by the U.S. Environmental Protection Agency in 2017 as a major factor. This lower-sulfur fuel standard has been particularly effective at reducing pollutants in older vehicles that contribute to smog, such as nitrogen oxides and volatile organic compounds (VOCs).

Data supporting these findings were compiled using traffic counts, vehicle registration records, and emissions testing for older cars, which were then processed through an emissions model. Andrew Gruber, executive director of the Wasatch Front Regional Council, noted that the reduction reflects a combination of vehicle technology and other evolving factors.