Sprawl and Health

Rajamani 2003 - "Assessing the Impact of Urban Form Measures in Nonwork Trip Mode Choice After Controlling for Demographic and Level-of Service Effects"

Jayanthi Rajamani, Chanra R.  Bhat, et al.
"Assessing the Impact of Urban Form Measures in Nonwork Trip Mode Choice After Controlling for Demographic and Level-of Service Effects"
Presented at the Transportation Research Board Annual Meeting (2003)
Session 747: Transportation and Urban Form
Wednesday, January 15, 2003, 7:30 PM - 9:30 PM, Hilton
On the Web

The abstract:
The relation between travel behavior and the local built environment has always been a contentious issue, despite several research efforts in the area. The current paper investigates the significance and explanatory power of a variety of urban form measures on nonwork activity travel mode choice. The data used for analysis is the 1995 Portland Metropolitan Activity Survey conducted by Portland Metro. The multinomial logit mode choice model results indicate that higher residential densities and mixed-uses promote walking behavior for nonwork activities.

 

Crane 1998 - "Does Neighborhood Design Influence Travel?: A Behavioral Analysis of Travel Diary and GIS Data"

Randall Crane and Richard Crepeau
"Does Neighborhood Design Influence Travel?: A Behavioral Analysis of Travel Diary and GIS Data"
Transportation Research Part D: Transport and Environment
3(4):225-238 (July 1998)
On the Web

 

From the abstract:
An analysis of household travel diary and GIS data for San Diego finds little role for land use in explaining travel behavior, and no evidence that the street network pattern affects either short or long non-work travel decisions. While results may vary in other areas, the empirical argument for using land use as an element of regional air quality or other environmental plans remains to be demonstrated.

(I didn't read the study intensively enough to comment, but see Cervero and Gorham (1995) for another study on Southern California.)

 

Cervero 2002 - "Built Environments and mode Choice: Toward a Normative Framework"

Robert Cervero
"Built Environments and mode Choice: Toward a Normative Framework"
Transportation Research Part D
7(4):265-284 (2002)
On the Web

From the abstract:
The analysis reveals intensities and mixtures of land use significantly influence decisions to drive-alone, share a ride, or patronize transit, while the influences of urban design tend to be more modest. Elasticities that summarize relationships are also presented...

Cervero 1995 - "Commuting in Transit Versus Automobile Neighborhoods"

Robert Cervero and Roger Gorham
"Commuting in Transit Versus Automobile Neighborhoods"
Journal of the American Planning Association
61(2):210-225 (Spring 1995)

From the abstract:
This article compares commuting characteristics of transit-oriented and auto-oriented suburban neighborhoods in the San Francisco Bay Area and in Southern California. Transit neighborhoods averaged higher densities and had more gridded street patterns compared to their nearby counterparts with auto-oriented physical designs. . . For both metropolitan areas, pedestrian modal shares and trip generation rates tended to be considerably higher in transit than in auto-oriented neighborhoods. Transit neighborhoods had decidedly higher rates of bus commuting only in the Bay Area. Islands of transit-oriented neighborhoods in a sea of freeway -oriented suburbs seem to have negligible effects on transit commuting.

Dumbaugh 2005 - "Safe Streets, Livable Streets"

Dumbaugh, Eric
"Safe Streets, Livable Streets"
Journal of the American Planning Association
Summer 2001; vol.71, n.3; pp.283-300
On the Web
Relevance: low

While conventional wisdom recommends limiting roadside hazards, such as trees, and increasing lane and shoulder width will reduce the number and severity of crashes where the driver leaves the roadway, this author posits that trees and narrow lanes encourage drivers to drive more slowly and carefully, reducing the total number of crashes.

The author cites a few studies, including on in Washington on an urban/rural arterial (HWY 99?), where the presence of trees, sign supports, and other fixed objects is associated with fewer total crashes while wider lanes and shoulders are associated with more crashes. The author then conducts his own study comparing different sections of the same roadway, finding similar results.

I'd say that the numerical results in this study are a little squishy, the they and the theory are nonetheless very compelling.

Handy 2005 - "Correlation or Causality Between the Built Environment and Travel Behavior? Evidence from Northern California"

Handy, Susan; Cao, Xinyu; Mokhtarian, Patricia
"Correlation or Causality Between the Built Environment and Travel Behavior? Evidence from Northern California"
Transportation Research Part D
November 2005; v.10, n.6; pp.427-444
On the Web
Relevance: medium

Handy et al surveyed residents of traditional and suburban neighborhoods on their travel habits, travel attitudes, perceived neighborhood attributes, and socio-economic status. They found that while residents of traditional neighborhoods drove 18% fewer miles than suburban residents, the variation in this cross-section could be better explained by differences in attitudes and SES factors than in the built environment.

When the authors separated out those who had moved in the past year for a quasi-longitudinal study, differences in the built environment (mainly in accessibility) appeared significant. The built environment seemed to affect increased walking more than decreased driving.

I'm a bit wary of the quasi-longitudinal part of this study. Why would the built environment be significant there but not in the cross-sectional analysis?

Lund 2002 - "Pedstrian Environments and Sense of Community"

Lund, Hollie
"Pedestrian Environments and Sense of Community"
Journal of Planning Education and Research   
2002 Associate of Collegiate Schools of Planning
On the Web
Relevance: medium-high

Lund's study is intended to gauge the community effects of New Urbanism-style architecture and neighborhood design. The study is conducted in two Portland neighborhoods, an inner-city neighborhood with traditional design and a modern-style suburban neighborhood (post-WWII). Researchers distributed questionaires door-to-door in the two neighborhoods using questions similar to the Nasar study. They got 57 responses (22 percent) in the traditional neighborhood and 49 (18.8 percent) in the suburban neighborhood.

The study found more sense of community in the traditional neighborhood than in the modern suburb. The most powerful subjective explanatory variable was "perception of walking"--the better that people felt about walking in the neighborhood, the higher their sense of community. Interestingly, there is one big counterpoint to this: the study found a negative correlation between destination trips (walking to the store or for other errands) and sense of community. That is, the more likely people are to walk to destinations, the lower their sense of community. Strolling trips--walking for pleasure--are positively associated with community, but destination trips are negatively associated.

One failing of this research is that the respondents are self-selected and many not be statistically accurate representations of their communities. Also, the number of respondents is relatively low and it may be difficult to obtain statistically valid results when using controls or regressions. Finally, we cannot be sure whether people's behavior and attitudes are determined by their urban environment, or whether people self-select into neighborhoods that reflect their values and preferences.

Nasar 1995 - "The Psychological Sense of Community in the Neighborhood"

Nasar, Julian
"The Psychological Sense of Community in the Neighborhood"
Journal of the American Planning Association
Spring 1995; v61, n2; pp 178-184
Relevance: high

There is more social capital--at least as conceived as neighborhood social ties--in mixed-use (and presumably higher density) communities than in single use communities. From the abstract: This paper describes the development and testing of an 11-item Likert scale of the sense of neighborhood community, using responses from 54 residents in three suburbs in Columbus, Ohio. One test of the scale with 100 residents in single-use and mixed-use areas near one another found significantly more sense of community in the mixed-use neighborhood. More sense of community emerged among married persons and couples with children as compared to singles and childless couples.

Much of this paper is devoted to justifying its research methodologies. Of particular interest is a list of 15 questions on page 181 that researchers used to ascertain neighborhood social ties. This could be of use in future primary research on social capital.

Ewing 2002 - "Measuring Sprawl and Its Impact"

Ewing, Reid; Pendall, Rolf; Chen, Don
"Measuring Sprawl and Its Impact"
Smart Growth America
2002
On the Web
Relevance: high

Ewing et al. created a sprawl index for ~83 metropolitan areas, incorporating density, land use mix, centeredness, and street accessibility. The authors also estimated the impact of sprawl on various transportation-related outcomes. They found that a higher degree of sprawl is associated with higher average vehicle ownership, daily VMT per capita, annual traffic fatality rate, and maximum ozone level; more sprawl was associated with a lower share of work trips by transit and walking. Note that, as with most sprawl studies, we can't assume a causal relationship.

Kelly-Schwartz 2004 - "Is Sprawl Unhealthy?"

Kelly-Schwartz, Alexia; Stockard, Jean, et al
"Is Sprawl Unhealthy? A Multilevel Analysis of the Relationship of Metropolitan Sprawl to the Health of Individuals"
Journal of Planning Education and Research
December 2004; v.24, n2; pp.184-196
On the Web
Relevance: high

The authors replicated and extended Ewing et al's work on the effect of sprawl on health. They compared self- and physican-rated health as well as a variety of chronic conditions across metropolitan areas while controlling for income, education, sex, etc. They found that sprawl does affect health somewhat, but in a complex way that is difficult to track.  It appears that a highly gridded street network is associated with better health while more density is associated with poorer health.  While sprawl was not significantly associated with a higher prevalence of chronic conditions, among those with those conditions, the gridded street network was associated with better health.