20 minute cities: unpacking the panacea

By on 6 February, 2019

This article originally appeared in issue 97 of Position magazine.

It’s an interesting time to be an urban dweller in Australia.

At a rate of one new person every minute and 23 seconds, the national population ticked past 25 million people in August 2018, with most of this growth occurring in the country’s largest cities.

Over the past few years planning departments at all levels of government are realising — with varying degrees of concern — that existing urban infrastructure is creaking under the weight of this rapid growth, and heavy lifting will be required to create and maintain liveable, adequately amenable environments for this swelling number of inhabitants.

A parliamentary report tabled in September 2018 called upon the federal government to develop and enact a national settlement plan, noting that for decades there has been no strategy in place for accommodating a growing population, particularly with respect to urban centres. The committee’s 37 recommendations included integrating master plans for states, territories and regions; high speed rail to connect the east coast cities, and the creation of a minister for cities and national settlement with a place in cabinet.

Simultaneously, the influence of the built environment on a population’s health and wellbeing is becoming more widely and better understood in cross-disciplinary research. Public health analyses and projections are more frequently incorporating a spatial component, and those concerned with analysing urban behaviours seem to have finally cut through — planning concepts that place access to amenity that promotes more active lifestyles are now broadly accepted as best practice, if not consistently realised at the municipal level.

Most definitions of liveability as it relates to urban built environments and their impact on residents’ health posit the concept as a nexus between walkability, access to public transport, access to outdoor spaces conducive to physical activity, and access to healthy food options as core requirements. A suite of other services accessible to all create varying definitions by context and practitioner, but most agree on the above key elements.

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In 2016, addressing the news media amid political debate over high speed rail access to Sydney’s second airport site, then-prime minister Malcolm Turnbull publicly invoked a concept that had been cropping up with increasing frequency in planning policy debates — the ’30-minute city’.

First championed in the political arena by the opposition, the concept of having an urban centre with essential services all within a 20 or 30 minute commute has now gained immense traction at state and federal levels, and interpretations of this concept are now being applied in practice as a liveability-related policy device.

The Greater Sydney Commission has since used the concept to underpin a series of transport-focused initiatives to enact its Metropolis of Three Cities master plan, and Plan Melbourne 2017 – 2050 (Plan Melbourne) is a Victorian initiative aimed at piloting a series of ’20 minute neighbourhoods’ across Melbourne — communities in which a series of identified features are accessible to all inhabitants within a 20-minute commute by public transport or bicycle.

Plan Melbourne 2017-2050 ’s 20 minute city definition:

  • Be safe, accessible and well connected for pedestrians and cyclists to optimise active transport
  • Offer high-quality public realm and open space
  • Provide services and destinations that support local living
  • Facilitate access to quality public transport that connects people to jobs and higher-order services
  • Deliver housing/population at densities that make local services and transport viable
  • Facilitate thriving local economies.

So this concept is now integral to key policy platforms and long-term planning initiatives in Australia’s two largest urban centres.

But the task of quantifying evidence to suggest exactly how this concept will transform the lives of residents once implemented is somewhat difficult.

According to Dr. Lukar Thornton, a senior lecturer in nutrition and population health at Deakin University, there is not a lot of empirical evidence to support the notion that the proximity of certain services or amenities to residences automatically leads to behaviours that encourage better health outcomes — a circumstance that he and his team are attempting to tackle.

Using a selection of Melbourne suburbs, Dr. Thornton and his team are undertaking research that aims to examine the assumption that ‘20 minute cities’ encourage more localised and healthier lifestyles. He said that while there’s a lot to like about the idea, but there’s much to consider when looking to apply it to a city of over 4.8 million people.

“So what this [20-minute neighbourhood] concept is trying to do is ensure that people have the opportunities within their local environment to engage in healthy food and physical activity behaviour. So from that point of view, it’s a good move,” he said.

“But I think the assumption that alone it will trigger healthy behaviours is a little bit of a misnomer. Something we’re looking to plug the individual back in the equation, and work out how for different individuals in particular, how those environmental opportunities are going to have different types of influences on their behaviour.”

Access to fresh foods has been shown to have a significant impact on health outcomes.

Dr. Thornton’s work has identified 11 measurable attributes within existing geospatial datasets, and have mapped Melbourne neighbourhoods within which these attributes can be accessed by foot in a 20-minute timeframe, within a 1.5-kilometre radius. After identifying where these neighbourhoods are (which can then be plotted against the government’s pilots), a survey of individual behaviours will take place, to examine how frequently particular activities are being undertaken in these zones, sampling a range of demographics in different regions across the city. Dr. Thornton said there are an array of reasons why somebody might not undertake an activity in their immediate locality.

“People are very time poor. So sometimes it might be more convenient to engage in some of these behaviours near their work, or near their child’s school, or some other places that they’re visiting more often,” he said.

“If someone’s leaving for work at seven in the morning and not getting home until six at night, then their opportunities to engage with some local facilities are almost removed. So if they’re only at home in the dark hours of the day then the likelihood that they’re going to go and walk to a neighbourhood feature like a park when they get home from work is really low as well,” he said.

Dr. Thornton said that tracking individual behaviours is critical to establishing the relationships between lifestyles and environmental features, citing the example of the interaction of public transport and access to supermarkets containing fresh food options. Someone commuting home by tram may be more tempted to get off early and walk to a local market, encouraging activity and healthier eating habits — versus car-based transit and the lure of drive through or delivered take-away at home, but these assumptions must all be tested to create evidence to inform appropriate interventions.

“Teasing out those who it’s important for is really crucial to this type of work. We want to understand which individuals are more reliant on their local neighbourhoods, and particularly if we can identify neighbourhoods where those particular demographics cluster together,” he said.

There are still many questions that remain about the implementation of Plan Melbourne’s 20-minute neighbourhoods, which is in its pilot phase. Whilst some of the features or amenities may beyond the scope of the government’s input, such as commercial decisions partially determining access to food options, Dr. Thornton hopes that the research may also identify beneficial neighbourhood features that cut across demographics and socioeconomic bands.

“It might be that we can identify that there’s a couple of key environmental attributes as well, that are really the triggers… that there’s a particular two or three features that come out as always being important. So rather than trying to make the neighbourhood a catch-all of everything, there might be one or two features that can be focused on.”

Relative to international best practice, cycling infrastructure is not closely integrated with other modes of transport in Australian cities.

Dr. Este Geraghty, chief medical officer and health solutions director at Esri, who will be presenting at Precision Public Health Asia 2018, said that this kind of evidence is essential to targeting initiatives to effect meaningful outcomes.

“It can be daunting to assess gaps in the liveability of a community and then try to mitigate those gaps broadly. One benefit of a geographic information system is that it can help governments tailor the right intervention and target the right places for deployment of that intervention,” she said.

“I think the whole point of doing a geographic analysis is that those planning aspects will vary by community. One community may need to focus providing sidewalks and green spaces to encourage residents to get more physical activity, whereas another community might prioritise affordable housing projects.”

Dr. Serryn Eagleson, deputy director at the Australian Urban Research Infrastructure Network (AURIN), has carried out detailed spatial analysis of pedestrian-vehicle accident patterns using PSMA Australia’s Geoscape dataset. She suggested that in terms of broad-brush interventions that boost liveability, the integration of cycling with other transport modes was a principle yet to be realised.

“The major gap I see is the opportunity for integrated active travel. In particular including cycling – many cities around the world integrate cycling with travel by trains and buses, however Australian cities such as Melbourne and Sydney have not embraced this,” she said.

Dr. Eagleson said that many seemingly intangible elements also contribute to utility and accessibility of a community, which can have dramatic impacts on the lives of inhabitants and should be factored into planning interventions.

“Key elements that are often overlooked are the sense of community and vibrancy at the street level. We have created wide streets with large buildings that are not permeable by pedestrians. Therefore it becomes more difficult to access where you need to go,” she said.

Dr. Eagleson carried out a study in 2009 titled Transforming Australian Cities, which used a spatial model to identify areas along tram and bus routes that could support higher density living and improved services with existing transport infrastructure. She said that while the challenges of ‘retrofitting’ existing urban infrastructure to support a rapidly expanding urban population to a new set of requirements are great, opportunities exist.

“We can do more to retrofit unused or undeveloped areas along the transit routes. We can also make greater connections between transport modes, especially cycling. We can increase the frequency of public transport. We can mandate good design with green and open space available,” she said.

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