TRUE publication
Evaluation of real-world vehicle emissions in Kampala, Uganda
The TRUE Initiative, in partnership with the United Nations Environment Programme, conducted a groundbreaking remote sensing campaign, the first of its kind in Africa, to offer real-world insight into the levels of pollution from vehicles operating in Kampala, Uganda.
Using plume chase technology, where a vehicle equipped with emission analyzers follows a target vehicle while sampling its exhaust plume, this project captured real-world snapshots from Kampala’s fleet in 2024. Researchers analyzed the results and observed that:
- Over 50% of gasoline passenger cars exhibited average nitrogen oxides (NOx) emissions consistent with pre-Euro certifications, suggesting potential malfunctions or removal of catalytic converters. Although newer gasoline passenger cars under 8 years old showed lower NOx emissions than older cars, their levels were still 5.5 times higher on average than Euro 4 limits.
- Diesel heavy commercial vehicles under 8 years of age showed 14% higher average NOx emissions than older counterparts. Similarly little differences in average real-world NOx emissions were observed among older and newer diesel vehicles across other groups— passenger cars, minibuses, and light commercial vehicles.
- Diesel minibuses, which had an average age of 25 years, showed NOx emissions more than 9 times higher than Euro 4 limits and elevated black carbon (BC) emissions. At least 16% of diesel minibuses over 15 years old exhibited visible black smoke from their exhaust during measurement and exhibited 6 times higher average BC emissions than vehicles aged between 8 and 15 years.
Uganda is already working to improve air quality, including by outlining new programs under its National Environment (Air Quality Standards) Regulations and e-mobility strategy. Based on these results, the TRUE Initiative recommends a strengthening of import requirements on all vehicle imports and developing a roadmap to meet Euro 6 standards. For maximum benefits, this should be complemented by routine vehicle inspection programs and mandatory follow-up maintenance that would quickly identify and repair high emitters. Finally, prioritizing public transport and modernizing the aging taxi minibus fleet would significantly reduce vehicle-related air pollution.
Cover Photo: Attendees participated in a live demonstration of plume chasing technology during a kick-off event for TRUE’s remote-sensing campaign in Kampala, Uganda. The workshop was organized by UNEP and local partners in July 2024.