Abstract
Citation
Cervero R, Kockelman K. Travel demand and the 3Ds: density, diversity, and design. Transp Res Part D 1997;2(3):199-219.
Abstract source: sciencedirect.com
The built environment is thought to influence travel demand along three principal dimensions —density, diversity, and design. This paper tests this proposition by examining how the ‘3Ds’ affect trip rates and mode choice of residents in the San Francisco Bay Area. Using 1990 travel diary data and land-use records obtained from the U.S. census, regional inventories, and field surveys, models are estimated that relate features of the built environment to variations in vehicle miles traveled per household and mode choice, mainly for non-work trips. Factor analysis is used to linearly combine variables into the density and design dimensions of the built environment. The research finds that density, land-use diversity, and pedestrian-oriented designs generally reduce trip rates and encourage non-auto travel in statistically significant ways, though their influences appear to be fairly marginal. Elasticities between variables and factors that capture the 3Ds and various measures of travel demand are generally in the 0.06 to 0.18 range, expressed in absolute terms. Compact development was found to exert the strongest influence on personal business trips. Within-neighborhood retail shops, on the other hand, were most strongly associated with mode choice for work trips. And while a factor capturing ‘walking quality’ was only moderately related to mode choice for non-work trips, those living in neighborhoods with grid-iron street designs and restricted commercial parking were nonetheless found to average significantly less vehicle miles of travel and rely less on single-occupant vehicles for non-work trips. Overall, this research shows that the elasticities between each dimension of the built environment and travel demand are modest to moderate, though certainly not inconsequential. Thus it supports the contention of new urbanists and others that creating more compact, diverse, and pedestrian-orientated neighborhoods, in combination, can meaningfully influence how Americans travel.
Full Text
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At A Glance
Physical Activity Environment Variables
| # | Type of Environment/Location |
|---|---|
| 50 | Total Environments/Locations |
| 50 | Community/Neighborhood as a Whole |
| # | Scale |
|---|---|
| 50 | Census tract |
| Measure | objective | perceived |
|---|---|---|
| Pedestrian Infrastructure | ✔ | ✘ |
| Population/Housing Density | ✔ | ✘ |
| Land Use | ✔ | ✘ |
| Facility Access/Availablity/Proximity | ✔ | ✘ |
| Cycling Infrastructure | ✔ | ✘ |
| Street Connectivity | ✔ | ✘ |
| Composite index | ✔ | ✘ |
| Pedestrian/Traffic Safety | ✔ | ✘ |
Domain(s)
Physical Activity Environment
Measure Type
GIS protocol/detailed description
Measure Availability
Not available
Number of Items
Not applicable
Study location
Metro/Urban
San Francisco Bay Area, CA, USA
50 neighborhoods corresponding to census tracts
Languages
Not applicable
Information about Development of Measure
Nothing to add
Study Design
Study Participants
Age
Not applicable
Sex
Not applicable
Race/Ethnicity
White
Non-white
Predominantly Low-income/Low-SES
No
Sample Size
Not Available
Study Design
Design Type
Develops new measures of the built environment and tests in 50 neighborhoods
Health Outcomes Assessed
None
Obesity Measures
Not applicable
BMI Measured or Self-reported
Not applicable
Covariates
Sociodemographic characteristics (socioeconomic status, race)
Data Reported on Race/Ethnicity
Quantitative data on study sample
Data Reported on SES
Quantitative data on study sample
SES-related Variables
Income
How To Use
Administration
Who Administered
Researcher-administered
Existing data (e.g., GIS, licensing)
How Administered
Not applicable
Time Required
Not applicable
Training Required
Not applicable
Instructions on Use
Not reported
Data Analysis
Data Collection/Analysis Costs
Not available
Data Collection/Protocol
Not available
Instructions on Data Analysis
Not reported
Validity (1)
| Type of validity | Construct/subscale assessed | Criterion measure used | Test/statistic used | Result |
|---|---|---|---|---|
| Other | Individual items not specifically validated but various factors were tested. "Overall, our research suggests that the effects of the Bay Area's built environment on travel demand were modest to moderate at best..." (p.216) | |||
Reliability (0)
There are no reliability tests reported for this measure.