Air quality and public health co-benefits of national transport policies

Abstract Introduction Transport is a major contributor to urban air pollution and premature mortality worldwide. This systematic review evaluates the air-quality and public health co-benefits of national and regional transport policies aimed at reducing population exposure to air pollution. Content Following PRISMA 2020 guidelines, this review synthesized evidence published between 2011 and 2024 on the health and environmental impacts of national or regional transport policies. Ten eligible studies were reviewed, covering diesel vehicle phase-outs, inspection and maintenance programs, electric vehicle incentives, fuel taxation, and promotion of public or active transport. Summary Across multiple settings, these policies were associated with reductions in PM 2 . 5 concentrations and with avoided premature mortality, respiratory and cardiovascular hospitalizations, and healthcare costs. The largest and most consistent health benefits were observed for integrated policy packages, particularly those combining regulatory and technological measures such as fuel quality improvements, vehicle electrification and diesel phase-out, complemented by behavioral or fiscal instruments. Most available evidence originates from high-income countries, while studies from low- and middle-income regions remain scarce. The limited number of eligible studies and their concentration in specific regions and modeling approaches constrain generalizability, especially to settings with different transport systems, resource availability, and air-quality profiles. Outlook Embedding health-impact assessment within transport planning and expanding long-term evaluations in low- and middle-income countries are essential to ensure equitable and sustained air-quality and health improvements. Future policy frameworks should prioritize source-oriented regulatory and technological measures such as vehicle electrification, fuel-quality regulation, and diesel phase-out implemented within integrated policy packages to maximize public-health co-benefits.