Road vehicles in the United States emitted 1.7 million tons of nitrogen oxides (NOx) in 2023. Emissions of NOx from road vehicles in the North American country have fallen considerably since the Clean Air Act was passed in 1970. Since then, increasingly stringent standards have resulted in NOx emissions from road vehicles to fall more than 85 percent relative to 2002 levels.
Heavy-duty trucks are a major source of transportation emissions in the United States. In November 2020, the EPA announced the launch of the Clean Trucks Initiative in a bid to decrease NOx emissions from HDVs.
Annual nitrogen oxides (NOx) emissions from road vehicles in the United States from 1970 to 2023
(in 1,000 tons)
* The source used 2002 and 2005 MOVES data to update 2002-2007 figures. The change in model resulted in noticeable changes in highway emissions from 2001 to 2002 for various pollutants.
Figures refer to on-road or highway emission sources, which include vehicles used on roads for transportation of passengers or freight.
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Environmental Protection Agency. (February 9, 2024). Annual nitrogen oxides (NOx) emissions from road vehicles in the United States from 1970 to 2023 (in 1,000 tons) [Graph]. In Statista. Retrieved December 03, 2024, from https://www.statista.com/statistics/1234938/road-transportation-nitrogen-oxide-emissions-us/
Environmental Protection Agency. "Annual nitrogen oxides (NOx) emissions from road vehicles in the United States from 1970 to 2023 (in 1,000 tons)." Chart. February 9, 2024. Statista. Accessed December 03, 2024. https://www.statista.com/statistics/1234938/road-transportation-nitrogen-oxide-emissions-us/
Environmental Protection Agency. (2024). Annual nitrogen oxides (NOx) emissions from road vehicles in the United States from 1970 to 2023 (in 1,000 tons). Statista. Statista Inc.. Accessed: December 03, 2024. https://www.statista.com/statistics/1234938/road-transportation-nitrogen-oxide-emissions-us/
Environmental Protection Agency. "Annual Nitrogen Oxides (Nox) Emissions from Road Vehicles in The United States from 1970 to 2023 (in 1,000 Tons)." Statista, Statista Inc., 9 Feb 2024, https://www.statista.com/statistics/1234938/road-transportation-nitrogen-oxide-emissions-us/
Environmental Protection Agency, Annual nitrogen oxides (NOx) emissions from road vehicles in the United States from 1970 to 2023 (in 1,000 tons) Statista, https://www.statista.com/statistics/1234938/road-transportation-nitrogen-oxide-emissions-us/ (last visited December 03, 2024)
Annual nitrogen oxides (NOx) emissions from road vehicles in the United States from 1970 to 2023 (in 1,000 tons) [Graph], Environmental Protection Agency, February 9, 2024. [Online]. Available: https://www.statista.com/statistics/1234938/road-transportation-nitrogen-oxide-emissions-us/
