Critics claim that smart growth policies are ineffective at reducing vehicle travel and achieving intended to objectives. This column critiques their arguments.
Many jurisdictions have smart growth policies that encourage more compact, mixed, multi-modal development. These policies result in a greater portion of new development being located close to – preferably within walking distance of – commonly-used services such as shops, schools and public transit. This often involves correcting current policies that favor lower-density, urban fringe development such as excessive parking requirements, restrictions on development density and mix, and transport planning practices that undervalue walking, cycling and public transport.
There are many justifications for smart growth policies: they increase accessibility (particularly for non-drivers), increase overall household affordability (combined housing and transportation costs), reduce the costs of providing public infrastructure and services, increase economic productivity and economic resilience (the risks to households of fuel price spikes, and therefore housing foreclosure rates), preserve openspace (farms and wildlife habitat), increase physical fitness and health, reduce stormwater management costs, and reduce external costs of automobile travel such as the traffic congestion, accident risk and pollution emissions.
If you are involved in community planning you will probably encounter critics who cite various reports which claim that smart growth fails to achieve these benefits. Two years ago the National Association of Home Builders commissioned Portland State University Professor Eric Fruits to publish such research, which I subsequently refuted in an article and a more detailed report. More recently, Wendell Cox posted a blog, The Transit-Density Disconnect, which also claims to prove that smart growth policies are ineffective at conserving energy and reducing air pollution, based on his analysis of professors Reid Ewing and Robert Cervero’s recent article, Travel and the Built Environment, published in the Journal of the American Planning Association.
Cox's argument is based on the following assumptions:
- Smart growth consists mainly of increased development density.
- Any vehicle travel reductions result from automobile-to-transit mode shifts.
- Increased regional density only causes modest automobile-to-transit commute mode shifts.
- Very high densities, such as those in Hong Kong and New York, are needed to achieve high transit ridership.
- Most households want to live in single-family homes, and so are harmed by the densities required for high transit ridership.
- Ergo, smart growth is ineffective at achieving its objectives and harms residents.
Let’s critique these assumptions.
First, smart growth is much more than just increased density; it consists of a set of complementary changes in development patterns that include increases in regional accessibility, density, mix, roadway connectivity, centricity (portion of jobs in major centers), efficient parking management, plus integrated improvements in walking, cycling, public transit services, and sometime carsharing. Although individually their impacts may seem modest, when implemented together they tend to reduce per capita vehicle travel 20-60%.
Second, there are many ways that smart growth reduces vehicle travel, including shorter trips (due to increased density and mix, and more connected roads), and shifts to active modes (walking and cycling), in addition to shifts to transit.
Third, commute mode shift is a poor performance indicator since commuting only represents about a fifth of total vehicle travel, and it fails to account for the reductions in trip distances that smart growth provides. Even if smart growth community residents commute by car, their commute and errand trip distances are shorter, and their children are more likely to walk and bicycle to school and to friends’ homes.
Fourth, smart growth provides many additional economic, social and environmental benefits besides emission reductions.
Infrastructure and service cost savings
Transportation cost savings
Economies of agglomeration
More efficient transportation
Improved accessibility options, particularly for nondrivers
Improved housing options
Public fitness and health
Greenspace and wildlife habitat preservation
Air and water emission reductions
Reduced “heat island” effects
Fifth, very high densities are not required to provide significant benefits. Some of the greatest benefits result from modest changes, such as simply increasing the portion of single-family housing located close to the regional center, in neighborhoods with local schools and commercial services, and sidewalks on most local streets; these changes cause only modest shifts to transit but significantly reduce trip distance and increase active travel, providing large reductions in per capita vehicle travel.
Sixth, real estate market research indicates that a growing portion of households want to locate in more accessible, multi-modal communities. This is not to suggest that everybody wants to live in transit-oriented neighborhood apartments, but North America has an abundant supply of large-lot single-family housing – approximately enough to meet future demands in most regions as aging Baby Boomers downsize from larger to smaller homes. Most housing demand growth is projected to be in small lot single-family and multi-family housing in walkable neighborhoods suitable for active younger households and aging retirees. Smart growth policies help communities prepare for the future.
When talking about smart growth it is important to communicate clearly what it is and the full range of benefits it can provide. We often say that smart growth means more compact development, by which we mean increased regional accessibility, density, mix, centrality, connectivity and walkability, but many people assume that this refers simply to increased density. We also fail to communicate the full set of benefits, including those to the residents and businesses located in more compact neighborhoods, and to the wider community. I recommend that you prepare for smart growth debates by having at hand fact sheets and websites that explain these points, suitable for various audiences.
What are the best information resources do you know of for communicating these concepts, besides those listed here? Please share your favorite smart growth myth-busters!
For More Information
Joe Cortright (2010), Driven Apart: How Sprawl is Lengthening Our Commutes and Why Misleading Mobility Measures are Making Things Worse, CEOs for Cities (www.ceosforcities.org); at www.ceosforcities.org/work/driven-apart.
Stuart Donovan and Ian Munro (2013), Impact Of Urban Form On Transport And Economic Outcomes, Research Report 513, NZ Transport Agency (www.nzta.govt.nz); at http://www.nzta.govt.nz/resources/research/reports/513/docs/513.pdf.
Reid Ewing and Fang Rong (2008), “The Impact of Urban Form on U.S. Residential Energy Use,” Housing Policy Debate, Vol. 19, Issue 1 (www.mi.vt.edu/web/page/580/sectionid/580/pagelevel/1/interior.asp), pp. 1-30.
Jonathan Ford (2009), Smart Growth & Conventional Suburban Development: Which Costs More?, U.S. Environmental Protection Agency (www.epa.gov/smartgrowth/sg_business.htm); at www.morrisbeacon.com/images/documents/MBD%20EPA%20infrastructure.pdf.
JRC (2011), Location Efficiency and Housing Type—Boiling it Down to BTUs, Jonathan Rose Companies for the U.S. Environmental Protection Agency (www.epa.gov); at www.epa.gov/smartgrowth/pdf/location_efficiency_BTU.pdf.
J. Richard Kuzmyak (2012), Land Use and Traffic Congestion, Report 618, Arizona Department of Transportation (www.azdot.gov); at www.azdot.gov/TPD/ATRC/publications/project_reports/PDF/AZ618.pdf.
Todd Litman (2011), “Can Smart Growth Policies Conserve Energy and Reduce Emissions?” Portland State University’s Center for Real Estate Quarterly (www.pdx.edu/realestate/research_quarterly.html), Vol. 5, No. 2, Spring, pp. 21-30; at www.vtpi.org/REQJ.pdf.
Todd Litman (2011), Critique of the National Association of Home Builders’ Research On Land Use Emission Reduction Impacts, Victoria Transport Policy Institute (www.vtpi.org); at www.vtpi.org/NAHBcritique.pdf.
Evert J. Meijers and Martijn J. Burger (2009), Urban Spatial Structure and Labor Productivity in U.S. Metropolitan Areas, presented at the 2009 Regional Studies Association annual conference ‘Understanding and Shaping Regions: Spatial, Social and Economic Futures’, Leuven, Belgium, April 6-8; at www.regional-studies-assoc.ac.uk/events/2009/apr-leuven/papers/Meijers.pdf.
Patricia C. Melo, Daniel J. Graham, and Robert B. Noland (2009), “A Meta-Analysis Of Estimates Of Urban Agglomeration Economies,” Regional Science and Urban Economics, Vol. 39/3, May, pp. 332-342; at www.sciencedirect.com/science/article/pii/S0166046208001269.
Renaissance Planning Group (2012), Smart Growth And Economic Success: Benefits For Real Estate Developers, Investors, Businesses, And Local Governments, Office of Sustainable Communities, U.S. Environmental Protection Agency (www.epa.gov); at www.epa.gov/smartgrowth/pdf/economic_success.pdf.
Gary Pivo (2013), The Effect Of Transportation, Location, And Affordability Related Sustainability Features On Mortgage Default Prediction And Risk In Multifamily Rental Housing, University of Arizona for Fannie Mae (www.fanniemae.com); at www.fanniemae.com/resources/file/aboutus/pdf/hoytpivo_mfhousing_sustainability.pdf.
Caroline Rodier, John E. Abraham, Brenda N. Dix and John D. Hunt (2010), Equity Analysis of Land Use and Transport Plans Using an Integrated Spatial Model, Report 09-08, Mineta Transportation Institute (www.transweb.sjsu.edu); at www.transweb.sjsu.edu/MTIportal/research/publications/documents/Equity%20Analysis%20of%20Land%20Use%20(with%20Covers).pdf.
Adel W. Sadek, et al. (2011), Reducing Vehicle Miles Traveled through Smart Land-use Design, New York State Energy Research And Development Authority And New York Department Of Transportation (www.dot.ny.gov); at www.dot.ny.gov/divisions/engineering/technical-services/trans-r-and-d-repository/C-08-29%20Final%20Report_December%202011%20%282%29.pdf.
Strategic Economics (2013), Fiscal Impact Analysis Of Three Development Scenarios In Nashville-Davidson County, TN, Smart Growth America (www.smartgrowthamerica.org); at www.smartgrowthamerica.org/documents/fiscal-analysis-of-nashville-development.pdf.
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