Table Of ContentPUBLIC BICYCLE SHARING AS A POPULATION-SCALE HEALTH
INTERVENTION FOR ACTIVE TRANSPORTATION IN DENVER, COLORADO
by
Andrew L. Duvall
B.A., University of Wyoming, Laramie, 1994
A thesis submitted to the
Faculty of the Graduate School of the
University of Colorado Denver in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy
Health and Behavioral Sciences
2012
This thesis for the Doctor of Philosophy degree by
Andrew L. Duvall
has been approved for the
Health and Behavioral Sciences
by
Debbi Main, Chair and Advisor
John Brett
Wesley Marshall
Eric France
Date: April 6, 2012
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Duvall, Andrew L. (Ph.D., Health and Behavioral Sciences)
Public Bicycle Sharing as a Population-Scale Health Intervention for Active
Transportation in Denver, Colorado
Thesis directed by Professor Debbi Main
ABSTRACT
Inadequate physical activity associated with acute car dependence is linked to
increased risk of obesity and related chronic health conditions, including heart disease,
diabetes, hypertension, depression and cancer. More than half of U.S. adults do not meet
the minimum recommended levels of physical activity.
This research is a mixed methods quantitative/qualitative study of the impact of a
public bicycle sharing system as a health intervention to induce active transportation
behavior. The primary quantitative outcome was a net increase in active transportation
through shared bike use. Qualitative outcomes included investigation of the effects of the
intervention on the behaviors of individual users, sources of motivation to participate and
continue use, indicators and pathways of diffusion of the intervention, and broader
impacts of the intervention.
Denver B-cycle annual members logged an average 60.3 minutes of weekly
checkout time, of which an estimated 35.5% to 50.0% replaced car trips. Annual
members differed significantly from the general population, being more likely to be male,
non-Hispanic, Caucasian, aged 25 and 44, more educated!"#$%&"&$’&()"$*+,-(!"higher
self-reported health status, and tended to be of normal weight.
Multivariate models of influencing factors found two key variables associated
with the number of checkouts among annual members. Commuting via shared bikes and
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the ability to replace car use increased the odds of higher checkouts. Proximity of
residence to Denver B-cycle stations was not a significant predictor. Women were as
likely as men to commute via shared bikes.
The use of Denver B-cycle increased net active transportation among annual
members. Users discovered their own meaningful ways in which the use of shared
bicycle best served their needs. Some participants best able to integrate Denver B-cycle
into their lifestyles reported weight loss, increased fitness, reduced car dependence, and
economic benefits.
The central implication of this research is that public bicycle sharing can be
effectively applied to increase active transportation behavior. The findings are
consequential for two trends: shifts away from car use toward use of shared bikes, and
increases in overall active transportation.
The form and content of this abstract are approved. I recommend its publication.
Approved: Debbi Main
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DEDICATION
I dedicate this work to my wife Julie, my daughters Stella and Piper,
and to my family and friends.
Their support was the wind at my back, and their love helped my wheels to spin.
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ACKNOWLEDGMENTS
The author is greatly appreciative of the U.S. National Science Foundation
Integrative Graduate Education and Research Traineeship (IGERT) program,!"#$%&!
’()*+!,-.!/#$01234567.!!
The Association of Schools of Public Health / Centers for Disease Control and
Prevention Environmental Health Community Design scholarship program, and the
Community Benefit Initiatives Committee of the 8)9:;*!<;*=)>;>?;!@-A-*)+-!">:?9?B?;!
C-*!D;)A?E!%;:;)*FE!G*-H9+;+!I;>;*-B:!F->?9>B;+!:BGG-*?.
Scholarship and camaraderie fostered by the faculty, staff and students of the
University of Colorado Denver Department of Health and Behavioral Sciences, and the
Center for Sustainable Infrastructure Systems at the University of Colorado Denver,
directed by Dr. Anu Ramaswami, has been of substantial and ongoing value.
The author wishes to express deep gratitude for the opportunities and support
afforded by dissertation committee chair Dr. Debbi Main, and committee members Dr.
John Brett, Dr. Wesley Marshall and Dr. Eric France. These talented and committed
educators contributed insight, encouragement, direction and advice, which have greatly
enhanced the quality of this work.
This research would not have been possible without a great many people. The
author wishes to thank those who directly affected the advancement of this work.
Organizations: The City and County of Denver, Denver Bike Sharing, BikeDenver, the
Denver Mayor’s Bicycle Advisory Committee, GreenPrint Denver,
Bikes Belong, and B-cycle.
Individuals: Parry Burnap, Steve Sander, Emily Snyder, Piep van Heuven,
Tracy Halasinski, Dick Gannon, Karen Good, Nick Bohnenkamp, Cindy Bosco,
Ken Gart, Corina Lindley, Nate Kvamme, Tim Blumenthal, Bob Burns,
Governor John Hickenlooper, Mayor Guillermo Vidal, and the volunteers, employees and
board of Denver Bike Sharing.
Special thanks goes to everyone who rides or aspires to ride a bicycle, for recreation, for
transportation, for the betterment of themselves and their community, and especially for
enjoyment.
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TABLE OF CONTENTS
CHAPTER
1. INTRODUCTION..........................................................................................................1!
Background.............................................................................................................1!
Significance Of The Study......................................................................................2!
Research Question and Specific Aims....................................................................7!
Overview of Methods.............................................................................................8!
2. LITERATURE REVIEW.............................................................................................10!
Development Of The Current Built Environment................................................10!
The Emergence Of Car Dependence...............................................................10!
Decoupling Transportation From Physical Activity.......................................11!
The State Of Obesity And Why It Matters.....................................................12!
Obesity Risk Through The Urban Form.........................................................14!
Beyond The Car: Public Bike Sharing............................................................16!
Guiding And Applied Theories For This Research..............................................19!
Informing the Study..............................................................................................21!
Intervention Through The Built Environment................................................22!
Intervention And The General Populations....................................................26!
The effects of environmental context.............................................................32!
Public Bicycle Sharing And Active Transportation........................................37!
Public Bicycle Sharing Participation..............................................................41!
Motivation To Use Public Bicycle Sharing....................................................44!
Summary Of Literature Review............................................................................45!
3. METHODS OF DATA COLLECTION AND EVALUATION..................................48!
Study Design.........................................................................................................48!
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Brief Glossary Of Terms Specific To This Research...........................................49!
Study Setting.........................................................................................................49!
Data Sources.........................................................................................................51!
Data Variables.......................................................................................................53!
Geographic Data Overview.............................................................................56!
Denver B-Cycle System Usage Dataset Overview.........................................56!
Denver B-Cycle User Survey Dataset Overview............................................57!
Select Participants.................................................................................................61!
Human Subjects Review.......................................................................................61!
Methods of Data Collection and Evaluation, by Specific Aim.............................61!
4. RESULTS.....................................................................................................................79!
Introduction...........................................................................................................79!
Aim 1: Examine the physical characteristics and human activity in the built
environment in which Denver B-cycle stations are situated.................................79!
Aim 1.1: Identify features that distinguish low and high performing sites..........79!
Characteristics Of The Built Environment At Select Stations........................79!
Market Street Station......................................................................................81!
16th and Little Raven.......................................................................................84!
REI..................................................................................................................87!
19th and Pearl Street........................................................................................91!
Union Station..................................................................................................93!
Denver Health.................................................................................................96!
Five Points......................................................................................................99!
15th and Tremont...........................................................................................102!
25th and Lawrence.........................................................................................105!
Pepsi Center..................................................................................................108!
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Analysis of Characteristics of the Built Environment at Select Stations......111!
Aim 1.2: Investigate the integration of Denver B-cycle within the existing urban
transportation system..........................................................................................115!
Station Network Density of Denver B-cycle................................................116!
Proximity To Transit.....................................................................................117!
Proximity To Bicycle Facilities....................................................................119!
Summary Of Denver B-Cycle Within The Urban Transportation System...121!
Aim 2: Describe the characteristics of Denver B-cycle users.............................123!
Description Of System-Wide Patterns Of Use..............................................123!
Checkout Activity.........................................................................................123!
Membership Characteristics..........................................................................128!
Aim 2.1: Determine demographic characteristics of Denver B-cycle users.......130!
Demographic data summary.........................................................................130!
Evaluating Gender, Ethnicity and Race........................................................134!
Evaluating Age Group, Educational Attainment and Household Income....135!
Health-Related Survey Data.........................................................................137!
Summary: Denver B-cycle Users Versus the General Population................146!
Aim 2.2: Investigate factors influencing Denver B-cycle use............................148!
Multivariate Modeling Of Number Of Checkouts By Denver B-Cycle Annual
Members.......................................................................................................149!
Commute Via Denver B-Cycle.....................................................................153!
Summary Of Factors Influencing Use..........................................................156!
Aim 2.3: Determine impacts of Denver B-cycle on shifts toward active
transportation......................................................................................................158!
Summary Of The Impact Of Denver B-Cycle On Active Transportation....160!
Aim 2.4: Identify active transportation benefits for Denver B-cycle annual
members..............................................................................................................161!
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Physical Activity Benefits.............................................................................161!
Summary Of Active Transportation Benefits For Denver B-Cycle Annual
Members.......................................................................................................167!
Aim 3: Provide an in-depth description of the impacts of Denver B-cycle as a
public health intervention...................................................................................168!
Motivation for Active Transportation Behavior...........................................168!
Health outcomes............................................................................................169!
Economic Outcomes.....................................................................................174!
Factors For Incorporating Behavior Change Into Lifestyle..........................176!
Diffusion of Use within Social Networks.....................................................181!
Social change................................................................................................187!
5. DISCUSSION AND LIMITATIONS........................................................................195!
Discussion...........................................................................................................195!
Interpreting The Findings.............................................................................195!
Denver B-Cycle As A Lifestyle Intervention...............................................196!
“Stealth” Intervention...................................................................................200!
Population Reached Through The Intervention............................................204!
Broader Impacts on Bicycling Activity In Denver.......................................206!
Long-Term Outcomes...................................................................................210!
Ongoing Intervention....................................................................................211!
Informing Application: Policy And Infrastructure.......................................214!
Theoretical Implications...............................................................................218!
Opportunities For Future Research...............................................................224!
Study Limitations................................................................................................228!
Conclusions.........................................................................................................230!
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