The Impacts of Car-Free Days and Events on the Environment and Human Health

PURPOSE OF REVIEW: In this paper, we seek to elucidate the impact of car-free days and events on human health. Car-free days and events are often designed to alleviate the impact of transportation-related air pollution, noise, physical inactivity, traffic congestion, or other detrimental externalities of private motor vehicle travel. We reviewed existing peer-reviewed and gray literature to understand the variety of potential public health impacts that have been measured as a result of car-free days or events and associated changes in environmental exposures and lifestyles. RECENT FINDINGS: The impacts of car-free days and events are highly variable and seem to depend on the scope (frequency, duration, and geographic size) and goals of each car-free day and event. Most of the existing literature measures impacts in terms of air and noise pollution and some studies focus on physical activity metrics. In some cases, car-free days and events were successful in reducing the concentration of certain air pollutants but had little or adverse impacts on the concentration of others. Often, traffic is diverted from cordoned areas to surrounding streets, displacing traffic congestion and adverse environmental exposures to other areas of a city, with potential understudied implications to environmental justice. SUMMARY: Car-free days and events are often an attractive policy option; however, they require intensive planning to be successful. The organization and execution of car-free days and events, as well as public support and stakeholder engagement, greatly influence the level of success and the sustainability of such initiatives. Health benefits may be a palatable and convincing argument to the general public. However, very few studies focus on actual health impacts associated with car-free days and events. Future research could be most useful if it focused on measuring health outcomes associated with car-free days and events through longitudinal studies.