According to Mitchell Silver, the New York City Parks and Recreation Commissioner and former president of the American Planning Association, sprawling suburbs across the US will face a crisis by 2030, with 25 million homes that nobody wants to buy surrounded by crumbling, under-funded infrastructure. In a related vein, a recent report by the Victoria Transport Planning Institute and LSE Cities estimated that sprawl costs America more than $1 trillion a year.
Such analyses provide an interesting counterpoint to other high-profile research on the supposed costs of land use regulation. Work by economists Chang-Tai Hsieh and Enrico Moretti claims that, in the US, people’s inability to move to expensive cities such as New York and San Francisco also costs American workers more than $1 trillion a year in ‘lost’ income. Were developers able to respond to demand, so the argument goes, employment in the New York metropolitan area might be eight times higher, while employment in the Bay Area would be between two and three times higher. Cities such as these are more productive, and so workers could demand and be paid more.
Of course, this assumes there would be somewhere to put them, which leads us back to the crucial issue of sustainable urban form. As acknowledged by the researchers themselves, achieving this boost to incomes would require a dramatic level of development. Hsieh and Moretti envision the New York metropolitan area becoming nine times its current size, meaning that more than half the country would live there (talk about sprawl). Meanwhile, half the cities in America would lose 80 percent or more of their population.
So, in one sense, the ‘argument’ is about how and where we locate the costs of different types of urban form (the physical characteristics that make up built-up areas, including the shape, size, density and configuration of settlements), and how we can come to a more balanced understanding of how this can affect not just the economy but society and the environment as well.
Sprawl, in the UK context, is also the focus of a new research project on the Location of Development being commissioned by the RTPI, which will examine the spatial implications of new housing developments in this country. As part of this project, the RTPI has produced a short briefing paper on urban form and sustainability, which provides initial evidence on the links between sustainable outcomes, urban form and the location of new housing developments, and how they impact upon the ability of an area to deliver efficient and resilient infrastructure, mitigate and adapt to climate change, and support accessibility and inclusivity in the built environment.
Naturally, what constitutes ‘sprawl’ is subject to definitional debate – views range along a continuum of more compact to completely dispersed development, and suburbs are often used as a proxy for sprawl in research on urban form and sustainability. Nonetheless, the research underpinning the briefing shows that low-density, car-oriented and dispersed developments are often disconnected from physical and social infrastructure, and that over time this can create significant economic, social and environmental problems.
Poor urban forms can contribute to higher level of greenhouse gas emissions and resource consumption health issues, social isolation and poverty. For example, Alan Berube, an expert on suburbs and co-author of Confronting Suburban Poverty in America, published by the Brookings Institute, has outlined the number of people in suburbs living in poverty is increasing. A Smith Institute report found the same trend in England and Wales. Another LSE Cities report, Cities and the New Climate Economy: The Transformative Role of Urban Growth, highlights many of the consequences of poorly managed growth for developing countries, and the importance of infrastructure development and spatial planning in response.
While it may be difficult to agree on a definition of sprawl in a way which makes sense internationally, and poor urban form comes in different forms in different countries, most countries face similar challenges for policy and practice. Urban forms are successful when they use resources sustainably, and provide a sound economic base which enables a good quality of life for their inhabitants. Successful infrastructure meets demand and provides reliable, cost effective, and high quality services, while the costs of providing and maintaining infrastructure for scattered developments are high. As a result, we need to plan now to ensure that new developments and infrastructure are located in the right places for sustainability.
The question, then, is how to achieve this. In the latest issue of Planning Theory and Practice, Kirk Brewer and Jill Grant from Dalhousie University, Canada, consider the challenges of achieving planning targets for density, urban intensification and mixed-use in particular for suburbs in mid-sized cities with relatively slow rates of growth. They look at suburbs in Dartmouth, Halifax over the last 50 years. This case illustrates the difficulty of changing engrained suburban patterns because of market forces, conflicting regulations, demographic shifts, and local conditions. Although policies generally support compact form and fine-grained mix, suburban development practices can remain remarkably resilient.
Because of their economic dynamics and political character differ from those of fast-growing metropolises, smaller cities may prove less receptive to changes in policy and development practice. While high land costs and low availability influence densities and land-use patterns in large centres with rapid growth, land costs remain relatively low in cities such as Halifax. Policies may recommend compact form for new suburban development, but planners can lack the mechanisms to require developers to shift to an urbanised pattern because of homebuyers’ (supposed) preferences and the absence of a strong market for high density mixed housing and mixed use.
Confronting and overcoming such barriers to more sustainable development is then a critical part of a trillion dollar question.