Abstract
Theory, common sense and modelling studies suggest that some interventions to mitigate carbon emissions in the transport sector can also have substantial short-term benefits for population health. Policies that encourage active modes of transportation such as cycling may, for example, increase population physical activity and decrease air pollution, thus reducing the burden of conditions such as some cancers, diabetes, heart disease and dementia. In this Perspective we systematically review the evidence from 'real life' transport policies and their impacts on health and CO2 emissions. We identified a few studies that mostly involved personalized travel planning and showed modest increases in active transport such as walking, and reductions in vehicle use and CO2 emissions. Given the poor quality of the studies identified, urgent action is needed to provide more robust evidence for policies.