By Camila Herrero, C40 Senior Manager Walking and Cycling, and Eduardo Peralta Lopez, C40 Clean Air Accelerator Manager
Active travel – encompassing walking, cycling, and other human-powered modes of transport – offers substantial health, environmental, and social benefits. It’s a sustainable and equitable solution that can transform cities by reducing air pollution, improving public health, and fostering vibrant urban environments.
One of the most cost-effective ways to promote sustainability, enhance health and reduce pollution in urban settings, active travel is virtually carbon-free. It doesn’t emit harmful air pollutants and has the lowest environmental impact among all transport options.
Urban infrastructure that supports active travel can replace millions of car journeys, directly reducing vehicle emissions and air pollution, which causes 8.1 million deaths annually. In most cities, around 35% of trips are under three kilometres and 50% are under ten kilometres – distances that can easily be covered by foot or bike.
Reducing air pollution
In cities where transport emissions are high, enhancing walking and cycling infrastructure can bring immediate air quality benefits. The transport sector accounts for a significant portion of urban greenhouse gas (GHG) emissions, and traffic is a major contributor to urban air pollution. Research shows that walking and cycling could reduce urban transport GHG emissions by 2–10%, making active mobility one of the most effective climate actions cities can pursue.
Cities around the world have been finding purposeful and creative ways to promote active mobility and harness its benefits. For example, C40’s Clean Air Accelerator – a cohort of 50 ambitious cities tackling emissions from the most polluting sectors – includes commitments from 42 cities to promote active mobility and enable a shift away from fossil-fueled cars to clean cities’ air. Their latest achievements can be found in the 2023 Progress report and explored in a visual map.
Over the past 20 years, air quality has generally improved in C40 member cities, though this trend varies by region. The Ultra Low Emission Zone in London caused a 53% drop in harmful nitrogen dioxide (NO2) levels in central London, and more than a 20% decrease in inner and outer London within a year of its expansion. Similarly, Berlin saw a 73% reduction in NO2 levels and an 86% reduction in particulate matter (PM10) levels over several years, showcasing the impact of policies that prioritise active travel and sustainable transport.
Healthier cities
The health benefits of active travel are well documented. Walking and cycling can prevent noncommunicable diseases associated with physical inactivity and reduce the risk of premature mortality. For example, in the Netherlands, cycling is estimated to prevent 6,400 deaths annually and extend life expectancy by six months. This reduces healthcare savings corresponding to more than 3% of the Dutch gross domestic product.
Even small increases in activity can greatly improve health, especially in people who are the least active; the adoption of brisk daily walks of just 11 minutes could prevent 1 in 10 early deaths, reducing risk by 23%. The benefits of physical activity outweigh the harms of exposure to air pollution (2016) and there’s evidence that, in the short term, physical activity can be protective against air pollution effects in healthy adults.
Moreover, road traffic injuries – a leading cause of death globally – can be reduced through active travel policies. A study in five Latin American cities showed that increasing walking and cycling mode shares could avoid about ten premature deaths caused by traffic incidents per 100,000 people each year.
Tools for policymakers
Cities can use various modelling tools to estimate the health impacts of active travel investments. These tools help policymakers plan and implement effective transport policies that maximise health benefits.
For instance, the High Impact Assessment tool and the Integrated Transport and Health Impact Modelling tool have shown that the health benefits of physical activity often outweigh the harms of air pollution, even in areas with high pollution levels.
Explore C40’s newest tools:
- Air Quality Through Urban Action transport module: This offers city staff a simple and rapid way to estimate air pollution and GHG emissions from a range of vehicle types, and health benefits from a variety of policies.
- Healthy Neighbourhood Explorer: Use the tool to discover the ranking of C40 cities’ neighbourhoods based on livability and mobility indicators, and simulate the health, economic and climate benefits of urban design actions at a local level.
Equity in active mobility
Active travel policies promote social equity by providing affordable and accessible transport options for all, particularly in lower-income and marginalised communities. The shift to active travel not only helps correct climate injustices – it also builds people-centred streets and supports a modal shift towards more sustainable urban transport systems – reducing air pollution impacts on the most vulnerable populations.
For example, Bogotá’s Barrios Vitales initiative focuses on transforming 33 neighbourhoods by enhancing access to bike lanes, public transport, and public services, thereby improving air quality and road safety while promoting social interaction and equity.
The way forward
Investing in active travel is a cost-effective strategy to improve urban health, reduce pollution, and build more connected and equitable cities. Cities like Addis Ababa, Dar es Salaam, and Lagos already have high rates of walking and cycling, demonstrating the potential for active travel solutions in diverse urban contexts.
With cities facing accelerating climate, air pollution, and public health crises, city leaders and policymakers must act boldly to scale up active travel initiatives. They must draw inspiration from cities that have successfully integrated active travel into their urban planning.
Now is the time to make cities healthier, more sustainable, and more resilient.