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...

Frank 2006 - "Many Pathways from Land Use to Health"

Lawrence D. Frank, James F. Sallis, et al.
"Many Pathways from Land Use to Health"
Journal of the American Planning Association
72(1):75-87 (Winter 2006)
On the Web
Relevance: high

From the abstract: in King County neighborhoods and found that a 5% increase in walkability was associated with:

• a per capita 32.1% increase in time spent in physical activity
• 0.23 point reduction in average body mass index
• 6.5% fewer vehicle miles traveled
• 5.6% fewer grams of nitrogen oxides emitted
• 5.5% fewer grams of volatile organic compounds emitted

See study for more details.

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?

Frank 2005 - "A Study of Land Use, Transportation, Air Quality, and Health (LUTAQH) in King County, WA: Executive Summary"

Frank, Lawrence (Lawrence Frank & Company, Inc.)
"A Study of Land Use, Transportation, Air Quality, and Health (LUTAQH) in King County, WA: Executive Summary"
September 27, 2005, Submitted to King County officials.
Relevance: high
On the Web (big pdf)

NOTE: The following summary includes only the sections of this report that deal with air quality and vehicle emissions.

The study examined per capita VOC and NOx emissions from both automobile and transit trips. It uses a variety of measures to classify urban, suburban and other land uses. Urban land uses are responsible for much lower air pollution, on a per capita basis, than suburban land uses. Interestingly, the strongest correlate to lower per capita emissions is “street connectivity.”

• “Significantly lower estimates for NOx were generated by respondents living in areas with higher levels of retail floor area ratio, intersection density, and land use mix and residential density. Increased street connectivity where people live appeared to be the most closely associated with NOx. Mean emissions of NOx declined from 29 to 23 grams per person per day, a 26 percent reduction, between residents of the most to the least connected environments.”
• “Significantly lower levels of VOC’s were found for respondents in areas with higher levels of floor area ratio and intersection density and residential density. Improvements to street connectivity where people lived appeared to be the most effective tool to reduce VOC’s as well. Mean emissions of VOC’s declined from 14 to 12 grams per person per day, a 7 percent reduction, for residents of the most to least connected environments.”

Leung 1998 - "Evaluation of Personal Exposure to Monoaromatic Hydrocarbons"

Leung, Pei-Ling; Harrison, Roy M
"Evaluation of Personal Exposure to Monoaromatic Hydrocarbons"
Occupational and Environmental Medicine
April 1998; v.55, n.4; pp. 249-257
On the Web
Relevance: high

The authors measured the exposure of 50 volunteers in the UK to various monoaromatic hydrocarbons (MAHs) over the course of 12 hour days. They found that urban volunteers were exposed to more MAHs than non-urban volunteers. Most of the total exposure is from the home, despite low concentrations, due to the vast amount of time spent there. Although little time is spent driving, the high concentration of MAHs in vehicles made it a noticeable contributor for office workers (5% of total exposure) 

Kingham 1998 - "Assessment of Exposure to Traffic-Related Fumes During the Journey to Work"

Kingham, Simon; Meaton, Julia; et al.
"Assessment of Exposure to Traffic-Related Fumes During the Journey to Work"
Transportation Research, Part D
July 1998; v.3, n.4; pp.271-274
On the Web
Relevance: medium-low

In a pilot study, the authors measured commuter's exposure to benzene and particulates using different modes (car, bus, train, road cyclist, path cyclist) but along similar routes(?). Findings include:

• The car driver had the highest mean exposure to benzene (108.3 micrograms/m^3) a factor of at least 4 and also the highest mean exposure to particulates (7.6 absorbance), but by a much smaller margin.
• Train riders had the lowest benzene exposure (12.9) and path cyclists had the lowest particulate exposure (2.7).
• The bus was slightly better than the road bike
• The exposure ratios for the car driver to the road cyclist were 4.05 for benzene and 1.26 for particulates.
• The exposure ratios for the road cyclist to the path cyclist were 1.73 for benzene and 2.41 for particulates.

Adams 2002 - "Assessment of Road Users' Elemental Carbon Personal Exposure Levels, London, UK"

Adams, HS; Nieuwenhuijsen, MJ; Colvile, RN.
"Assessment of Road Users' Elemental Carbon Personal Exposure Levels, London, UK"
Atmospheric Environment
November 2002; v.36, n.34; pp.5335-5342
On the Web
Relevance: low

The authors measured exposure to elemental carbon (EC) a component of diesel exhaust, along various routes, using different modes, and in summer vs. winter.  They found that exposure levels were higher:

• for cars, followed by buses and bicycles (cyclists may have lower exposure because they don't get stuck in traffic and keep "away from the central road 'tunnel of pollution'.";
• along the most congested central route, perhaps due to higher traffic density and a street canyon effect;
• in winter, perhaps due to colder engines and more stable meteorological conditions.

Fruin 2004 - "Black Carbon Concentrations in California Vehicles and Estimation of In-Vehicle Diesel Exhaust Particulate Matter Exposures"

Fruin, Scott A; Winer, Arthur M; Rodes, Charles E.
"Black Carbon Concentrations in California Vehicles and Estimation of In-Vehicle Diesel Exhaust Particulate Matter Exposures"
Atmospheric Environment
August 2004; v.38, n.25; pp.4123-4133
On the Web
Relevance: low

The authors measured black carbon (BC) concentrations inside vehicles driven around LA and Sacramento. BC is typically associated with diesel emissions. The authors found that the most important predictor of in-vehicles BC concentrations was the type of vehicle followed, with diesel buses and delivery trucks that had ground-level exhaust pipes being the worst. Following a gasoline powered car did not increase BC concentrations.

The authors also estimate daily exposure to diesel particulate matter (DPM), concluding that compared to earlier models, "in-vehicle DPM exposures appear to make very significant contributions to overall DPM exposures, randing from approximately 30-55% of total DPM exposure on a statewide, population basis.  Thus the in-vehicle microenvironment may be the most important route of overall DPM exposure, though only 1.5h day-1 is spend there, on average."

Friedman 2001 - "Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma"

Friedman, Michael S; Powell, Kenneth E; et al.
"Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma"
Journal of the American Medical Association
February 21, 2001; vol.285, n.7; pp.897-905.
On the Web
Relevance: low

The authors compared the level of air pollution and asthma events during the Atlanta Olympics to levels just before and after. They found that ozone levels and asthma events were lower during the Oympics, likely due to changes in traffic patterns. The number of asthma acute care events decreased 41.6% in the Georgia Medicaid claims file.  Organizers increased public transportation, closed the downtown to cars, encouraged workers to change work hours, and made other adjustments. There are several caveats to this study, so we may not want to quote it alone, but it could be one building block of the case.

Adams 2001 - "Determinants of Fine Particle (PM2.5) Personal Exposure Levels in Transport Microenvironments, London, UK"

Adams, HS; Nieuwenhuijsen, MJ; Colvile, RN
"Determinants of Fine Particle (PM2.5) Personal Exposure Levels in Transport Microenvironments, London, UK"
Atmospheric Environment
September 2001 v.35, n.27; pp.4557-4566
On the Web
Relevance: medium-low

The authors measured concentrations of fine PM on fixed routes using different modes (car, bus, bicycle) in London. They found that route was a significant factor, explaining 20% of the variation, but mode was not. Wind speed explained 18% of the variation. "Personal exposure levels were reasonable correlated with urban background FSM [fixed site monitor] concentrations."

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.

Chertok 2004 - “Comparison of Air Pollution Exposure for Five Commuting Modes in Sydney – Car, Train, Bus, Bicycle and Walking”

Chertok, Michael ; Voukelatos, Alexander ; Sheppeard, Vicky ; and Rissel, Chris
“Comparison of Air Pollution Exposure for Five Commuting Modes in Sydney – Car, Train, Bus, Bicycle and Walking”
Health Promotion Journal of Australia
April 2004; v.15,n.1; pp.63-67
On the Web (pdf)
Relevance: high

The study measured the BTEX pollutant and NO2 exposure of 44 subjects on their regular daily commutes, each lasting at least 30 minutes each way.  Car commuters were exposed to the highest levels of BTEX pollutants, while bus commuters were exposed to the highest levels of NO2.  Train (light and heavy rail) commuters were exposed to the lowest levels of all pollutants measured.  Walking and cycling commuters were exposed to significantly lower levels of BTEX than car commuters and of NO2 than bus commuters. 

Batterman 2002 - “Levels and Composition of Volatile Organic Compounds on Commuting Routes in Detroit, Michigan”

Batterman, Stuart A; Peng, Chung-Yu; and Braun, James.
“Levels and Composition of Volatile Organic Compounds on Commuting Routes in Detroit, Michigan”
Atmospheric Environment
December 2002; v.36,n.39-40; pp.6015-6030
On the Web
Relevance: high

Batterman et al measured VOCs in cars and buses during rush hour on commercial, industrial, and residential routes in Detroit, Michigan.  They found that:

• VOC concentrations along roadways and in buses were similar;
• route did not much affect differences in air quality; however, the buses all traveled on congested 4 lane roads during rush hour; and
• VOC concentration varied significantly over time, which the authors attribute to changes in weather, mainly inversions and wind speed and direction;
• vehicle sources dominate industrial sources in influencing urban VOC concentrations, corroborating earlier studies; and
• VOC concentrations on roadways were much higher than concentrations at the two fixed-site monitoring stations in Detroit.  For example, BTEX concentrations measured at the fixed sites were 2-4 times lower than levels measured in traffic.

Harruff 1998 - “Analysis of Circumstances and Injuries in 217 Pedestrian Traffic Fatalities”

Harruff RC, Avery A, Alter-Pandya AS.
“Analysis of Circumstances and Injuries in 217 Pedestrian Traffic Fatalities”
Accident Analysis and Prevention
January 1998; v.30,n.1; pp.11-20
On the Web
Relevance: high

Harruff et al analyzed 217 pedestrian fatalities in King County, WA to describe the most common situations and characteristics of pedestrian fatalities.  The average annual pedestrian fatality rate for all pedestrians overstates the risk for responsible, able-bodied adults but understates the risk for vulnerable groups such as the elderly.  Alcohol consumption, disregard of traffic rules, and being male also increase the fatality risk.