coll. - Rethinking urban sprawl moving towards sustainable cities

Home to more than half of the worlds population, cities are the engines of economic growth and employment. The 200 largest urban areas generate more than 60% of jobs and growth in the OECD. With the share of world population living in urban areas projected to reach 70% by 2050 (86% in OECD countries), the importance of cities will only increase.

Cities are increasingly interconnected, global arenas and face a range of environmental, economic and social challenges. They are responsible for over two-thirds of energy consumption and more than 70% of CO2 emissions globally. The OECD has estimated that outdoor air pollution could cause 6 to 9 million premature deaths a year by 2060, with cities particularly hard hit. Cities face a wide range of interconnected challenges, such as road congestion, lack of housing affordability, and social exclusion. Urban sprawl, a particular form of urban development, is often cited as a driver of these challenges.

Rethinking Urban Sprawl: Moving Towards Sustainable Cities offers a new perspective on urban sprawl, contributing to a better understanding of its evolution, causes and consequences. It provides new insights on the design, delivery and implementation of policies to shift urban development patterns towards more sustainable trajectories. This will be crucial to achieve the Sustainable Development Goals and meet the objectives of the Paris Agreement.

In particular, the report looks at past and current urban development patterns of OECD cities and establishes a new set of indicators that quantify the multiple dimensions of urban sprawl. It shows that cities in most of the examined OECD countries have become more fragmented, and the share of low-density areas in population and urban land coverage has increased. While there are differences between and within countries, urban form is generally evolving in a way that induces higher car dependency and longer commuting distances. Such a development pattern also substantially increases the per capita costs of providing public services. Water, sanitation, electricity, public transport, waste management, policing and other services that are key for well-being are much more expensive to provide in fragmented areas of low-density.

Therefore, coherent and targeted policy action is urgently needed from different levels of government to steer urban development towards more sustainable pathways. Policy instruments for greener and more cost-effective urban transport, such as appropriate pricing of car travel and parking, can be particularly effective in addressing the environmental consequences of urban sprawl in the short run. Land-use policy reforms promoting socially desirable levels of population density, such as relaxing maximum density restrictions and incentivising developers to provide public infrastructure for new constructions, can bear fruit in the longer run.

How cities develop over the next years will determine progress on addressing key environmental, economic and social challenges, including climate change and access to affordable housing. This report provides an important step towards assessing the state and implications of urban growth patterns, and identifies policies to steer cities towards inclusive and green growth.

Angel Gurra

OECD Secretary-General