TRUE publication

Pollutant emissions from light-duty vehicles across North America: A comparative analysis 

With the conclusion of The Real Urban Emissions (TRUE) Initiative’s first-ever remote sensing campaign in Latin America, TRUE now possess real-world emissions data from three of the largest and most populous countries in North America. These complementary datasets—encompassing measurements from vehicles in Mexico City, Mexico; the United States (Colorado and Virginia); and Alberta, Canada—pave the way for a comparative analysis of real-world light-duty vehicle emissions across the continent.  

This analysis provides insights into emission trends over time, the impact of regulatory standards, and vehicle performance. For example, the measurements show a consistent and substantial decrease of at least 70% in fleet-average emissions with newer model years for hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxide (NO) across all four locations. Trends in Alberta, Virginia, and Colorado are closely aligned, reflecting Canada’s adoption of U.S. Environmental Protection Agency standards since 1988. On the other hand, vehicles in Mexico City, particularly taxis, exhibit significantly higher emissions. In part, this trend can be attributed to factors such as the use of gasoline with higher sulfur content and Mexico’s national emissions standards, last updated in 2005; new model years show significant improvement in NO and CO emissions, but even these vehicles have much higher HC emissions than vehicles in Canada and the United States.