Sprawl and Urban
• The county’s growth rate is in the upper
quartile of the “economic area’s” annual
county household and employment growth
• The county’s growth rate exceeds the
average annual national county growth
• The county’s absolute level of growth
exceeds 40% of the average annual
absolute county growth.
Urban Sprawl Defined
• The landscape sprawl creates has four
– a population that is widely dispersed in low-density
– rigidly separated homes, shops, and workplaces;
– a network of roads marked by huge blocks and poor
– a lack of well-defined, thriving activity centers, such
as downtowns and town centers.
• Most of the other features usually associated
with sprawl - the lack of transportation choices,
relative uniformity of housing options or the
difficulty of walking - are a result of these
Measuring Sprawl Objectively
• Based on this understanding, the researchers
set about creating a sprawl index based on four
factors that can be measured and analyzed:
– Residential density;
– Neighborhood mix of homes, jobs, and services;
– Strength of activity centers and downtowns;
– Accessibility of the street network.
• Each of these factors is in turn composed of
several measurable components, a total of 22 in
• The places where housing is most spread out include a
number of medium-sized metro areas in the southeast.
• These are places where growth has mostly occurred
during the automobile era, and have been without
topographic or water related constraints that otherwise
• The prevalence of low residential densities in this
particular region is striking and merits further
Neighborhood Mix of Homes,
Shops, and Offices
• One of the characteristics of sprawl is the strict segregation of
different land uses. In sprawling regions, housing subdivisions are
typically separated—often by many miles—from shopping, offices,
civic centers, and even schools.
• This separation of uses is what requires every trip to be made by car,
and can result in a “jobs-housing imbalance” in which workers cannot
find housing close to their place of work.
• More traditional development patterns tend to mix different land uses,
often placing housing near shops, or offices above storefronts.
• Measuring the degree of mix is therefore an important descriptor of
Comparison of Low-Density Sprawl
With New Urbanism
Strength of Metropolitan Centers
• Metropolitan centers are activity centers that help businesses thrive
and support alternative transportation modes and multipurpose trip
• Connectedness can be represented by concentrations of
employment or population.
• It can also represent a single dominant center or multiple
Lessons from The Most Sprawling
• The most sprawling metro area of the 83 surveyed is Riverside,
California, with an Index value of 14.22. It received especially low
– it has few areas that serve as town centers or focal points for the
community: for example, more than 66 percent of the population lives over
ten miles from a central business district;
– it has little neighborhood mixing of homes with other uses: one measure
shows that just 28 percent of residents in Riverside live within one-half
block of any business or institution;
– its residential density is below average: less than one percent of
Riverside’s population lives in communities with enough density to be
effectively served by transit;
– its street network is poorly connected: over 70 percent of its blocks are
larger than traditional urban size.
Impacts of Sprawl on Travel
What is a Growth County?
• Have Maintained Double-Digit Rates of Population
Growth for Each Census Since 1950
• Are Located in the Nation’s 50 Largest
Metropolitan Areas as of the 2000 Census
• Come in Three Sizes:
– “MEGA” Over 800,000 People
– “Edge” Between 200,000 to 800,000 People
– “New Metropolis” Under 200,000 People
Three Types of Growth
• MEGA Counties - 23 massively enlarged, growth-
accelerated counties with a total population of 37 million
• Edge Counties – 54 areas mostly at or near the edge of
their regions and often at the leading edge of
metropolitan growth with a total population of 20.8
• New Metropolis Counties – 47 counties lying mostly at
the regional fringe, generally do not contain large
concentrations of commerce, and are updated versions
of bedroom suburbs with a total population of 4.7 million.
• Found mostly in booming regions of the Sunbelt.
– Harris County, TX - Maricopa County, AZ
– Travis County, TX - Palm Beach, FL
– Orange County, CA - Broward County, FL
– Clark County, NV - Miami–Dade County, FL
– Santa Clara County, CA - Travis County, TX
– Fairfax County, VA - Santa Clara County, CA
– Maricopa County, AZ - Dallas County, TX
• They can be big suburban counties outside the
nation’s largest cities
• Now perhaps as important to the nation’s commerce
as any of its large traditional cities.
• Home to many of the largest office centers in the
nation that lie outside of a central business district
• Typically contain “Edgeless Cities” which are a form of
sprawling office development that never reaches the
densities or cohesiveness of Edge Cities (mostly isolated
office buildings at varying densities over vast swaths of
• Older metropolitan areas have high-density traditional
cores and rings of older, pedestrian-oriented suburbs,
they also feature new, so-called sprawling growth, which
is often found in Edge Counties.
• Edge Counties are growth engines because in many of
these older regions they account for a majority of new
people added despite often containing just a small share
of the total metropolitan population.
New Metropolis Counties
• So-named because they are new to their regions -
having been added to the official metropolitan
statistical area after 1971.
• They reflect the new metropolitan growth pattern -
they are all low-density, centerless, and sprawling.
• The New Metropolis Counties may be Edge
Counties in formation.
• Residents of New Metropolis Counties often work in
Edge Counties, which means that more commutes
are originating in what were once rural areas.
• Thus, commercial development in Edge Counties
fuels the emergence of New Metropolis Counties,
which in turn promotes even more population growth
farther and farther from the regional core.
• New Metropolis Counties are the new suburbs of
suburbs, which in the future may spawn even more
• A boomburb is a large, rapidly growing city that remains
essentially suburban in character even as it reaches
populations more typical of urban core cities.
• A boomburb is an area that currently has more than
100,000 residents and has maintained double-digit rates
of population growth in each recent decade, but is not
the largest city in its metropolitan area.
• Boomburbs almost never have a dense central business
• And their housing, retail, entertainment, and offices are
spread out and loosely configured.
• They're located in 14 metro areas
surrounding Phoenix, Los Angeles, San
Diego, San Francisco, Denver, Miami,
Tampa, Chicago, Las Vegas, Portland,
Dallas, Salt Lake City, Norfolk and Seattle.
• Boomburbs range from Mesa, Ariz., with
nearly 400,000 residents, to Westminister,
Colo., with just over 100,000.
On the southeastern outskirts of the Phoenix metropolitan area, Chandler grew
from just 3,799 residents in 1950 to 176,581 residents in 2000, based on 10-year
census figures. The differences between these images indicate that a significant
portion of that growth happened after 1989.
1989 Florida Growth Pattern Study: Capital Facility
Sprawl Versus Compact Development
(per dwelling unit; 1990 dollars)
Comparison of Residential Densities on
Costs & Revenues
Monterey County, CA
Built Environment Effects to
(Ewing and Cervero, 2002)
REGIONAL EFFORTS TO
CONTROL URBAN FORM
• Inasmuch as land use planning is usually at the center of
regional planning, regional planning efforts usually focus
on how the urban area could look different than it would
• The desired difference is usually in the direction of more
centers and density.
• At the regional level, the options for urban form are few
in theory and in practice. For any predicted amount of
growth, a region can
– (1) continue what has in U.S. cities been a universal pattern of
suburbanization (residential growth accommodated in relatively
low density development, primarily at the urban fringe);
– (2) try to get that growth to concentrate more in the central city
and major subcenters within the existing metropolitan area
(urban growth boundaries); or
– (3) deflect the growth to satellite cities not contiguous to the
Comparing and Evaluating
• Some metro areas were found to sprawl badly in all
dimensions. These include Atlanta, Raleigh and
• A few metros did better than other regions in all four
factors; among them are San Francisco, Boston, and
• Other metro areas are more of a mixed bag; in those
cases, the individual factor scores can tell us more about
the characteristics of individual metro areas. For
example, while the Columbia, SC or Tulsa, OK metro
areas contain large swaths of low-density development,
the presence of a number of strong centers bring them
up in the overall ranking.
• And while San Jose, California, has slightly higher
density than most metro areas, its lack of centers of
activity pulls it down in the overall ranking.
Sprawl’s Impact on Quality of Life
• Higher rates of driving and vehicle
• Increased levels of ozone pollution.
• Greater risk of fatal crashes.
• Depressed rates of walking and
alternative transport use.
• No significant differences in
Alleged Negative & Positive
Impacts of Sprawl
Markets Where Policies to Change Urban Form are Likely to Have
Direct (Internalized) Effects on Prices
• This figure shows the hypothesis
that the main effects of a change
in form should be captured
through changes in the costs of
providing infrastructure services.
• An important and defensible
assumption is that the effect of
urban form on households,
businesses, and governments
occurs mainly through a derived
demand for infrastructure, an
• The conclusion is that the impact
of changes in urban form on the
cost of infrastructure is probably
the single most important impact
• That approach, with infrastructure
as the sole concern, does not
cover everything, either technically
Sprawl and Health Concerns
• Because this study is ecologic and cross-sectional in nature, it
is premature to imply that sprawl causes obesity, hypertension,
or any other health condition.
• Our study simply indicates that sprawl is associated with
• Future research using quasi-experimental designs is needed to
tackle the more difficult job of testing for causality.
“Relationship Between Urban Sprawl and Physical Activity, Obesity, and Morbidity” by Reid Ewing, Tom Schmid, Richard Killingsworth,
Amy Zlot, Stephen Raudenbush in the American Journal of Health Promotion, Inc., September/October 2003, Vol. 18, No. 1
Sprawl, Weight and Blood Pressure
Sprawl & Obesity
Policy Recommendations for
Regions Wishing to Reduce Sprawl
1. Reinvest in Neglected Communities and
Provide More Housing Opportunities
2. Rehabilitate Abandoned Properties
3. Encourage New Development or
Redevelopment in Already Built Up Areas
4. Create and Nurture Thriving, Mixed-Use
Centers of Activity
5. Support Growth Management Strategies
6. Craft Transportation Policies that
Complement Smarter Growth
Selected Statistics On Urban/Suburban
Density & Growth In 15 MSAs, 1990–2000
Population Per Square Mile
MSA 2000 Density
Little Rock-N. Little Rock 201
Rockford IL 239
Normal(675.26, 399.60) Chattanooga 255
1.8 Knoxville 281
1.6 Memphis 378
1.4 New Orleans 394
Values x 10^-3
1.2 St. Louis MO 407
1.0 Charlotte-Gastonia-Rock Hill 444
Minneapolis-St. Paul 490
0.8 Pittsburgh 510
0.6 Denver 561
0.4 Dallas 569
Ft. Worth-Arlington 584
0.2 Atlanta 672
0.0 Buffalo-Niagara Falls 747
Washington DC 756
Salt Lake City-Ogden 825
Values in Thousands Cleveland-Lorain-Elyria 832
Tampa-St. Pete-Clearwater 938
< 0 %
9 .0 .0
5 % > Baltimore 979
0 1 .3 3
1 3 Detroit 1,140
New Haven-Bridgeport-Stamford 1,261
Source: U.S. Census Bureau Newark 1,289
San Jose 1,304
Statistical Abstract of the United States, 2002 Oakland 1,642
San Francisco 1,705
Central City Employment Statistics
MSA % CC Emp
Tampa-St. Pete-Clearwater 14.66%
Normal(0.32440, 0.18489) Salt Lake City-Ogden 15.62%
New Haven-Bridgeport-Stamford 20.39%
3.0 Baltimore 21.04%
Buffalo-Niagara Falls 24.02%
2.5 Washington DC 24.25%
Ft. Worth-Arlington 29.82%
1.0 Atlanta 31.13%
New Orleans 32.15%
0.5 Little Rock-N. Little Rock 32.65%
Charlotte-Gastonia-Rock Hill 37.18%
Rockford IL 37.82%
1.1 St. Louis MO 41.83%
San Francisco 43.83%
< 0 %
9 .0 .0
5 % >
0 2 .6 9
0 2 Houston 46.82%
San Jose 50.55%
Source: US Census Bureau data Memphis 55.78%
www.demographia.com Jacksonville 65.84%
Minneapolis-St. Paul 96.84%
Comparing Sprawl and Smart
Surface Coverage of Different
Land Use Classes
Household Annual Municipal
Costs by Residential Densities
Transportation Costs That
Increase with Sprawl
Annual Household Auto Costs
Under Four Densities
Sprawl – A Reprise
• Automobile dependency has a number of negative land use impacts.
• It increases the amount of land paved for roads and parking which has
economic, social and environmental costs.
• Automobile oriented cities devote up to three times as much land to roads
and parking as traditional, pedestrian-oriented cities.
• Automobile dependency tends to result in lower density, urban periphery
development (sprawl), which imposes a number of economic, social and
• Sprawl increases the amount of land used per capita for roads, parking, and
buildings and reduces the land left for agricultural and wildlife habitat.
• Under most conditions it increases costs for public services.