Future heavy-duty emission standards: An opportunity for international harmonization

Air pollution continues to be a major threat to public health. In 2017, 96% of the European Union’s urban population was exposed to ground ozone levels in excess of air quality guidelines (AQGs) from the World Health Organization (WHO). In the United States, the picture is similar. An estimated 93% of the U.S. urban population lives in cities with ground-level ozone levels higher than WHO’s AQGs. NOx emissions from motor vehicles play a significant role in the formation of ground level ozone. Although heavy-duty vehicles in the United States and the European Union account for less than 5% of the total on-road fleet, they are responsible for close to half of NOx emissions from mobile sources. In this report, the ICCT makes recommendations for the regulatory processes in the European Union and the United States, with an emphasis on harmonizing future heavy-duty vehicle emission standards.