Sprawl vs. Smart-Growth - A Study

The Global Commission on the Economy and Climate just published a study (http://bit.ly/1bjMKjK) on the effects of urban sprawl. The report not only investigates the costs of sprawl, but also points out benefits of “smart growth”, i.e. compact, mixed and multi-modal developments. Furthermore, it identifies policies that can improve health, safety and wealth in communities.

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Effects of Sprawl

The study helps to better understand the costs of sprawl. These costs include "displacement of agriculturally and ecologically productive lands, increased infrastructure costs, and increased transportation costs including increases in per capita facility costs, consumer expenditures, travel time, congestion delays, traffic accidents and pollution emissions, plus reduced accessibility for non-drivers, and reduced public fitness and health”. Sprawl reduces access by affordable modes like biking, walking and transit, it contributes to a concentration of poverty and social problems in urban neighborhoods, and increases infrastructure costs by decreasing agglomeration efficiencies. 

Other interesting results of the report are: 

  • Urban sprawl costs the American economy more than US$1 trillion per year
  • The 20% most sprawled American cities spend 50% more on infrastructure per year and capita than the least sprawled cities ($750 vs. $502)
  • In sprawled neighborhoods the risk of being killed in a car accident is between two and five times higher than in smart communities
  • The probability of being overweight is more than twice as high in sprawled areas compared to more walkable neighborhoods

Smart-Growth Policies

As public policies favor dispersed development and underprice public infrastructure and motor vehicle travel, sprawl seems to result at least partially from public policy. The report identifies policies in the areas of improved customer options, efficient pricing and neutral planning that could increase economic efficiency and equity. Among them are: 

  • Encouragement of compact, multi-modal developments, that favor resource-efficient transport modes
  • Reduction of car travel and limitation of vehicle ownership, e.g. by auctions of vehicle registrations
  • Efficient pricing of parking and roads
  • Changed parking regulations 
  • Better walking, biking and transit options
  • Accessibility- instead of mobility-based planning
  • More affordable housing in accessible multi-modal areas
  • Accessibility- instead of mobility-based planning
  • Increase density to more than 30 residents per hectare along traffic lines (e.g. to enable frequent transit service)
  • Internalization of all impacts in the planning process

The authors conclude that smart growth policies that aim for compact communities can provide social, environmental and economic benefits. We propose that besides of policies, smart technologies - used within cities and for city planning - can contribute to achieve this goal. Of course, implementing these policies (and finding a consensus) and getting the technologies into place comes with considerable efforts and trade-offs. But considering the economic, social and environmental challenges that we are facing, we should not hesitate to work on less sprawled and more livable cities.