Economic and environmental costs are the realities of rapidly expanding human impact.
An analysis of urban sprawl and the policies inadvertently encouraging it in the United States has determined that it comes with a price tag of more than $1 trillion per year. This cost was revealed by Todd Litman, lead author of the 2015 ‘NCE Cities – Sprawl Subsidy Report’ published by The New Climate Economy , who examined a number of associated factors associated with urban sprawl to arrive at this astounding figure. Looking at evidence regarding the role that development policies play, Litman describes the costs and benefits of sprawl in economic terms, defining the optimal amount and type of urban expansion of a range of city types. In his report, Litman proposes an alternative (which he terms ‘smart growth’) to excessive urban sprawl and presents suggested policies that can be implemented by different levels of Government.
The fundamental issues with urban sprawl are:
- It increases the amount of land developed per capita (by up to 80%) and the total distance travelled by motor vehicles (by up to 60%)
- Agriculturally and ecologically productive land becomes more fragmented
- Infrastructure costs increase
- Increased transport-related costs (including travel times, congestion delays and vehicle emissions)
The world’s population is expected to nearly quadruple during the years 1950 to 2050 and transition from 80% of people living in rural areas to 80% living in urban areas. Between 2015 and 2050 this translates to approximately 2.2 billion new urban residents in developing countries. The growth of cities in developing countries has extremely significant economic, social and environmental implications on both a local and global scale. Public policies must guide this growth to ensure benefits are maximised, costs are minimised, and a sustainable legacy is left for future generations.
The costs associated with urban sprawl have been classified as either ‘internal’ or ‘external’. Internal costs are those that directly affect people who inhabit urban locations, with external costs affecting those residing outside of city areas. Under a best-case assessment conducted by this report, external costs were calculated at $400 billion, with the internal cost at $626 billion (total $1.026 trillion). Under a worst-case estimate of urban sprawl, external costs are approximately $500 billion and internal costs $650 billion. This represents a total of $1.15 trillion. While it may not seem like a great amount when dealing in the trillions, the difference between the costings for each of these scenarios ($1.026 and $1.15 trillion for best and worst-case, respectively) is important because the latter includes additional social factors such as accessibility for non-drivers and lower economic productivity– factors of great importance when seeking to establish well planned and sustainable urban areas.
Litman defines smart growth as a set of principles that can be applied in a number of ways. In rural settings, it facilitates the establishment of compact walkable villages with single and multi-family dwellings arranged around a commercial centre. In large cities, smart growth creates dense mixed-use neighbourhoods arranged around major transport stations. In mature cities it translates into incremental infill in existing neighbourhoods. Density is a widely available and easy to understand indicator that is often positively correlated with other smart growth indicators such as development mix, transport network connectivity and transport diversity.
Smart growth requires a minimum density of 30 residents per hectare to provide adequate demand for schools and public transport within walking distance of homes. This density can be achieved with a demographic mix of 30-50% single family, 25-35% townhouse and 25-35% multi-family housing. Development policies prior to the year 2000 favoured expansion over infill, restricted building density and height, and imposed minimum parking and setback requirements that contributed to a self-fulfilling prophecy of sprawl and motor vehicle dependence. Governments and professional organisations must now support smart growth policies to mitigate the negative impacts, however in order to do so they must acknowledge the major policy shift that smart growth signifies.
At a municipal and regional Government level, policy options to realise smart growth include:
- Reforming zoning codes to permit higher densities and encourage more mixed multi-modal development within existing urban areas
- Ensuring that new greenfield developments are well planned to create complete communities that include good walking, cycling and public transport access
- Significantly reducing or eliminating minimum parking requirements in zoning codes and implementing more efficient parking management practices (such as pricing on-street parking and efficiently enforcing parking regulations)
At a national level, smart growth policy options include:
- Reducing and ultimately eliminating motor vehicle fuel subsidies, and implementing regularly scheduled fuel tax increases
- Providing diverse and stable urban transport funding options such as regional fuel taxes, road tolls, emission fees and parking taxes.
Litman presents several case studies in this report, showcasing Korea and India where new sustainable transport systems are being developed as smart growth principles are embraced- demonstrating the applicability of smart growth in both developing and developed countries, and the positive impacts that smart growth policies can facilitate right away. These initiatives see capital previously invested in enabling urban sprawl being re-channelled into programs that have immediate environmental, social and economic benefits for all.
The findings of Litman’s New Climate Economy report should serve as a wake-up call to Governments at all levels across the globe. The $1 trillion plus cost of urban sprawl in the US is clearly not just related to localised land use, infrastructure and transport costs. Looking at it from a wider perspective, urban sprawl should also be considered as an international environmental issue. The ‘expansion at all cost’ mantra that dominated pre-2000 development policies and led to urban sprawl in Western countries such as the US is part of the reason we are now facing changes in rainfall, seasonal land and sea temperatures, and food crop yields (among other impacts). Measurably increasing economic and environmental costs are the realities of rapidly expanding human impact. A major shift in town planning policies and urban development strategies are required to address urban sprawl and initiate positive change, not just in the urban centres of America but around the world.
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