More than half of Australian adults don’t get enough physical activity – and our cities aren’t helping.
A healthy level of physical activity isn’t just about going to the gym or playing sports, it’s about the built environment around us and how easier or harder it is to walk around.
Walking is an easy, popular, equitable and accessible way to reach the World Health Organization (WHO) recommendations that we each get 150 minutes a week of moderate-intensity physical activity.
But large parts of Australian cities are not pedestrian-friendly. Instead, our urban planning is car-centric, creating barriers to healthy, active and sustainable lifestyles.
I am part of an international team of researchers, led by Professor Billie Giles-Corti of RMIT University, who have developed indicators of healthy and sustainable urban environments, which will help achieve the WHO 2030 target to reduce physical inactivity by 15% – now published as a Lancet Series on Global Health on town planning, transport and health.
Using data from the International Physical Activity and Environment Network (IPEN) study, our research, led by Professor Ester Cerin of Australian Catholic University, calculated that for people to walk enough to To achieve the WHO target, neighborhoods need populations dense enough to support nearby services like shops and public transport – at least 5,700 people per km².
Cities also need connected roads or paths for people – around 100 intersections per km², and easily accessible public transport – around 25 stops per km².
Pedestrian-friendly neighborhoods are associated with reduced risk of non-communicable diseases, and features of the built environment such as population density, street connectivity, and access to public transportation are important for neighborhood walkability. .
Our further research in The Lancet Global Health The series, led by Dr Geoff Boeing of the University of Southern California, then used these criteria to assess 25 major cities in 19 countries.
We found that the three Australian cities included in the study – Melbourne, Sydney and Adelaide – did not meet the optimal thresholds for walkable population density and street connectivity.
Only 51% of Sydney’s population, 18% of Melbourne’s and none of Adelaide’s population live in neighborhoods that meet the minimum population density threshold. This reflects the traditional Australian suburb characterized by low-density, self-contained housing.
As contrasting examples, 97% of the population of Lisbon in Portugal and 96% of the population of Valencia in Spain live in areas with adequate population density. The average for reaching density thresholds was much higher for cities in middle-income countries than for high-income countries.
Australian cities also have poor street connectivity.
Only 13% of the population of Sydney and Adelaide and 21% of Melbourne live in neighborhoods that meet the optimal threshold of connected streets to help meet the WHO physical activity target.
This figure is well below the average proportion of the population living in areas with adequate road connectivity, for cities in the high-income and middle-income countries in the study.
Cities with a high percentage of the population meeting or exceeding the optimal intersection density thresholds include Lisbon, Portugal (99%), Bern, Switzerland (98%) and Hong Kong (92%). Poor street connectivity makes it less convenient to walk to everyday destinations like stores, parks and schools.
Compared to the other cities in this international study, the neighborhoods of Sydney, Melbourne and Adelaide have overall low walkability.
Similar to previous Australian studies, we also found that access to walkable neighborhoods is inequitably distributed across these three Australian cities. While expensive downtown areas are more walkable, many mid- and outer suburban areas are heavily car dependent.
Australian cities also have insufficient access to frequent public transport to support walking.
We found that only 49% of Melbourne’s population is within 500 meters of public transport that runs at least every 20 minutes, compared to 54% in Adelaide and 58% in Sydney.
By contrast, in Sao Paulo, Brazil, 94% of the population have nearby access to frequent public transport.
Inadequate urban planning policies can contribute to our car-centric built environments.
As part of The Lancet Global Health Series, I conducted a study to assess and compare the presence and quality of policy frameworks in the 25 cities. We found that Australian cities – like many other cities studied – lack sufficiently ambitious and evidence-based policies to promote healthy, active and sustainable cities.
For example, despite all the rhetoric supporting health and sustainability in our cities, Adelaide and Sydney have no policy requirements for minimum street connectivity, and Melbourne and Sydney have government housing density targets. ‘State that are too low to sustain the walk.
Australian cities also lack measurable policy targets for providing walking and cycling infrastructure, and Adelaide’s policy targets for walking and cycling are too low to optimize physical activity.
These policy limitations undermine efforts to increase physical activity through active transportation, improve air quality, and reduce greenhouse gas emissions.
To improve health, Australian cities need urban planning policies that are evidence-based, measurable and enforceable. Policies that contradict the evidence urgently need to be reviewed and policy gaps must be closed.
Urban design and transportation policies should include measurable goals that align with the optimal thresholds needed to achieve WHO physical activity goals. Further research is also needed to establish optimal thresholds for health improvement for other urban design and transportation features to help guide policymaking.
Urban planning policies and interventions must also focus on reducing current inequalities in access to walkable urban environments.
All levels of government must work together, with the private and community sectors, to ensure integrated planning and delivery of the full range of transportation and urban design features needed for healthy and sustainable cities.
Policy makers could start by taking note of our Global Observatory of Healthy and Sustainable Cities – an international collaboration that shares the findings of The Lancet Global Health Series.
The Global Observatory hosts reports and city dashboards for the 25 cities in the study, including Melbourne, Adelaide and Sydney. These can be used to guide urban planning to better support population health and achieve WHO physical activity goals. And other dashboards are planned.
The Global Observatory’s 1000 Cities Challenge invites interested researchers and policy makers to get involved in calculating indicators for their own city.
This the research was led by the Global Healthy and Sustainable City-Indicators Collaboration leadership team: Professor Billie Giles-Corti (RMIT University), Dr Melanie Lowe (University of Melbourne, Dr Geoff Boeing (University of Southern California) , Professor Ester Cerin (Australian Catholic University), Dr Deborah Salvo (Washington University), Professor Erica Hinckson (Auckland University of Technology), Professor Jim Sallis (Australian Catholic University), Carl Higgs (RMIT University), Dr Deepti Adlakha (North Carolina State University), Professor Anne Vernez Moudon (University of Washington), Dr Jonathan Arundel (RMIT University), Dr Shiqin Lui (Northeastern University). Other contributors from the University of Melbourne include Professor Mark Stevenson and Thanh Ho.
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