Realising the aspiration of 30-minute cities in Australia

The research breaks new ground by extending the idea of accessibility, defined as the ‘ease of reaching desired destinations’. Traditionally an accessibility measure evaluates the state of workers’ access to jobs. The researchers extended the idea to measure accessibility to social infrastructure, such as schools and hospitals, critical to supporting daily life.

The study ‘New housing supply, population growth, and access to social infrastructure’, undertaken for the Australian Housing and Urban Research Institute (AHURI), reveals that access to schools and hospitals in greenfield areas lags notably behind regional averages. Public transit and walking access is most impacted, with the lag in car access appearing less severe than other modes of transport. This also shows that despite planning aspirations of transit-based cities, Australian cities are still car dependent.

The COVID-19 pandemic, with associated lockdowns and strict limits on travel and the movement of people, has underscored the urgent need for providing better, more proximate social infrastructure.

Fragmented planning systems and delivery agencies, and a lack of coordinated and timely data sharing, have created significant lag times between population growth and new infrastructure delivery in greenfield development areas.

Using Sydney, Brisbane and Perth as case studies, the research provides governments with a practical new tool and proposal for better data sharing that could revolutionise how the planning system operates.

Lead researcher, Dr Somwrita Sarkar, said access to social infrastructure such as schools, health services, leisure and recreation facilities is critical to community wellbeing in newly developing areas.

“Our research proposes an evidence-based, data-rich, information-sharing framework and tool that would be a critical first step in ameliorating so many of the infrastructure delivery failures that have dogged Australia’s planning systems across all levels of government for decades,” Dr Sarkar said.

The monitoring and coordination tool developed during the project enables small area population projections by using building activity as a lead indicator to population growth, and the computation, mapping, and visualisation of fine spatial scale accessibility for various social infrastructure dimensions. In this report, the tool is used to demonstrate accessibility to schools and hospitals.

“Our research also identifies the scope for far more innovative uses of existing social infrastructure. Access to all infrastructure will be strengthened if mixed use, coordinated development of social infrastructure is promoted. For example, by combining the use of schools with other community functions such as libraries or immigrant support programs, because schools effectively become a largely wasted, centrally accessible resource outside of school hours,” Dr Sarkar said.

The project also brings out the value of combining a diverse set of academic expertise to solve a common wicked problem. Lead researchers forming the team, Dr Emily Moylan, Professor David Levinson, and Professor Nicole Gurran, used modelling, accessibility research, and policy planning expertise. While project research officers, Mr. Hao Wu and Ms Rashi Shrivastava contributed to the development and implementation of the research.

Novel data sources used in the project included:

• Geoscape dataset—a longitudinal dataset comprising the footprints and attributes of over 15 million buildings across Australia
• Median speed data for every road link across Australia (2019 data)
• Open Street Maps (OSM)—open-source map data
• General Transit Feed Specification (GTFS)— developed by Google, that defines a common format for public transportation schedules and associated geographic information.

The data was used to create ‘spatial accessibility profiles’ that provide a powerful basis for community engagement around priority development and infrastructure decisions, applicable to schools and health facilities, parks, recreation, and retail services.

“As well as informing planning and funding decisions, the accessibility profiles provide a powerful measure of urban performance and spatial equity. They can be used to inform and measure progress towards sustainable transportation and a reduction in car dependency,” Dr Sarkar said.

Planning and industry experts consulted as part of the study recognised the value of publicly available ‘real-time’ data to inform and measure social infrastructure accessibility.