Global demand for transport (for both passenger and freight) is growing rapidly, and it is predicted to triple between 2019 and 2050 (OECD 2019). The global vehicle fleet is projected to more than double from 1.2 billion to 2.5 billion between 2015 and 2050, with most of the growth occurring in Low- and Middle-Income Countries (World Bank 2017).Despite progress made on fuel efficiency and electrification, road-transport energy demand also continues to rise. The International Energy Agency reports that transport emissions grew at an annual average rate of 1.7% from 1990 to 2022, faster than any other end-use sector except for industry (IEA 2025). As of 2025, 78 countries still use high-sulfur fuel, and 92 countries lack adequate vehicle emission standards, meaning 2 billion people have limited or no access to clean fuels and vehicles (CCAC 2025). Strengthening fuel quality and vehicle emission standards, in addition to expanding access to reliable and accessible public transport, remains a fundamental near-term measure while zero-emission technologies scale up. 24% 24% Road transport contributes to 24% of global nitrogen oxides (NOx) emissions (a precursor to ground-level ozone) (CEDS 2021). 8% 8% Road transport contributes to 8% of global black carbon emissions (CEDS 2021). 385,000 385,000 On-road vehicle emissions were responsible for 385,000 premature deaths in 2015 (ICCT 2019). 2 billion 2 billion 2 billion people have limited or no access to low-sulfur fuel and/or advanced vehicle emission standards and technology (UNEP 2025). Solutions and multiple benefits Cutting emissions from road transport requires a combination of policy, regulatory, and infrastructure interventions. Introducing or strengthening fuel quality and vehicle emission standards, combined with strong inspection systems, is key to removing high polluting vehicles from the road. The full implementation of the Global Strategy to Introduce Low Sulfur Fuels and Cleaner Diesel Vehicles could reduce small particulate and black carbon emissions from cars, buses and trucks by over 90% by 2030. In addition, accelerating the electrification of the fleet for all on-road vehicles can eliminate tail-pipe emissions and reduce noise pollution in urban areas.The expansion of efficient, reliable and accessible public transport, as well as the promotion of active mobility through urban planning and safe infrastructure is also essential to reduce congestion, lower fuel consumption, and improve urban air quality and overall quality of life. AQMx Sectoral Guidance: Improving Fuel QualityThe AQMx Sectoral Guidance provides practical, action-oriented instructions for implementing proven policies and measures that reduce air pollutants and short-lived climate pollutants. Each guidance package breaks down what to do, how to do it, and what capacities are needed at national and local levels to deliver results. It brings together the best available knowledge from partner organizations—including data, tools, models, and technical resources—into a single, easy-to-use reference point. This one-stop-shop approach helps governments avoid duplication and quickly identify solutions that work.The guidance is designed to meet the needs of air quality managers, national and local authorities, and sectoral agencies working to cut pollution while supporting development goals. It responds directly to common implementation barriers, offering clear steps, practical examples, and links to further support.