Archives: Vehicles

 

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) 

More notes...

 

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."