Substantial policy changes to control obesity, limit chronic disease, and reduce air pollution emissions, including greenhouse gasses, have been recommended. Transportation and planning policies that promote active travel by walking and cycling can contribute to these goals, potentially yielding further co-benefits. Little is known, however, about the interconnections among effects of policies considered, including potential unintended consequences. Objectives and methods: We review available literature regarding health impacts from policies that encourage active travel in the context of developing health impact assessment (HIA) models to help decision-makers propose better solutions for healthy environments. We identify important components of HIA models of modal shifts in active travel in response to transport policies and interventions. Results and discussion: Policies that increase active travel are likely to generate large individual health benefits through increases in physical activity for active travelers. Smaller, but population-wide benefits could accrue through reductions in air and noise pollution. Depending on conditions of policy implementations, risk tradeoffs are possible for some individuals who shift to active travel and consequently increase inhalation of air pollutants and exposure to traffic injuries. Well-designed policies may enhance health benefits through indirect outcomes such as improved social capital and diet, but these synergies are not sufficiently well understood to allow quantification at this time. Conclusion: Evaluating impacts of active travel policies is highly complex; however, many associations can be quantified. Identifying health-maximizing policies and conditions requires integrated HIAs.
Bibliographical noteFunding Information:
Contributions from the various authors were discussed and developed during a workshop held on November 9–10th 2009 for the launch of the Transportation Air pollution and Physical ActivitieS: an integrated health risk assessment program of climate change and urban policies (TAPAS) project. TAPAS is a four year project funded in part by the Coca-Cola Foundation and the Agencia de Gestio d'Ajuts Universitaris i de Recerca. The funders have no role in the planning of study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. All authors are independent from the funders.
- Air pollution
- Built environment
- Physical activity
- Risk assessment