How city design and transport planning can improve health

A new series, published in The Lancet quantifies the health gains that could be achieved if cities incentivised a shift from private car use to cycling and walking, and promoted a compact city model where distances to shops and facilities, including public transport, are shorter and within walking distance.

These changes could achieve significant reductions in non-communicable diseases such as cardiovascular disease and diabetes as well as increasing physical activity and reducing pollution. Importantly, in cities with high levels of private car use such as Melbourne, London and Boston, the authors say that promoting walking and cycling must be matched by improvements to infrastructure that separate motorised transport to protect cyclists and pedestrians from road injuries.

Over half of the world's population lives in cities, and rapid urbanisation is only expected to increase in the coming years. By 2050, large cities in the USA, China and India are predicted to see their populations increase by 33%, 38% and 96% respectively.

Population growth in cities means increasing demands on transport systems. Sprawling residential developments in the USA, Australia and New Zealand limit the ability of people to walk or cycle in their daily commute and make public transport expensive to deliver.

Private car use has increased dramatically in Brazil, China and India leading to declines in physical activity, increases in air pollution and increased rates of road death and serious injury, all of which combine to increase overall levels of chronic disease and injury.

 The authors of the Series identify key interventions that, when combined, encourage walking, cycling and public transport use, while reducing private car use. These include having shops and services within walking distance, a mix of employment and housing across the city, reducing the availability and increasing the cost of parking, infrastructure that supports safe walking and bicycling, open spaces, reducing distance to public transport, and making neighbourhoods safe, attractive and convenient for public transport.

Series lead Professor Mark Stevenson, University of Melbourne, and colleagues designed a 'compact cities model' where land-use density was increased by 30%, average distance to public transport reduced by 30%, and diversity of land-use increased by 30%. They also factored in a 10% shift from private cars to either cycling or walking - a target similar to that of policies in many European cities such as Zurich.

"City planning policies can affect health, both positively and negatively. A major incentive is that designing cities for health and active transport, rather than automobile-dependence, also makes the cities more environmentally sustainable helping cities to achieve the UN's Sustainable Development Goals," says series author Professor James Sallis, University of California, San Diego, USA.