Good city planning produces co-benefits for individual and planetary health and wellbeing. In 2016, a Series on Urban Design, Transport and Health was published in The Lancet, drawing attention to the importance of integrated upstream city planning policies as a pathway to creating healthy and sustainable cities. City planning policies determine the local built environment and transport features that influence transportation choices and affect exposures to health risk and protective factors. The 2016 Lancet Series proposed a set of city planning indicators that could be used to benchmark and monitor cities.

The Lancet Global Health Series on Urban Design, Transport, and Health, published in May 2022, follows up on the 2016 Series in The Lancet. In this new Series, we demonstrate how those indicators can be used to measure urban design and transport policies and features in cities.

We present the results of a 3.5 year case study in 25 cities in 19 lower-middle and high-income countries where we conducted policy analysis and assessed built environment and transport features using geospatial indicators. We also identified thresholds for built environment interventions that could help achieve the World Health Organization’s target for increasing physical activity by 15% by 2030. Through this new Series in The Lancet Global Health, we show how the indicators can guide decisions about what must change in order to create healthy and sustainable cities; how research can be used to guide urban policy to achieve urban and population health; create tools so that cities can replicate our indicators, and explore ‘what next’ is needed to create healthy and sustainable cities, particularly in light of the COVID-19 pandemic and climate change.