Developing a Guide for Estimating Benefits of Closing Gaps in Active Transportation Networks (2026)
Chapter: Front Matter
Developing a Guide for Estimating Benefits of Closing Gaps in Active Transportation Networks
Mike Sellinger
Alta Planning + Design
Portland, OR
David Wasserman
Kim Voros
Alta Planning + Design
Seattle, WA
Elizabeth Yarnall
Alta Planning + Design
Atlanta, GA
Joseph Broach
Jennifer Dill
Portland State University
Portland, OR
Jessica Schoner
Safe Streets Research + Consulting
Minneapolis, MN
Rebecca Sanders
Safe Streets Research + Consulting
Portland, OR
David Von Stroh
Cambridge Systematics
Seattle, WA
Chris Porter
Cambridge Systematics
Medford, MA
Conduct of Research Report for NCHRP Project 08-149
Submitted July 2024
NCHRP Web-Only Document 426
Developing a Guide for Estimating Benefits of Closing Gaps in Active Transportation Networks
© 2026 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trademarks of the National Academy of Sciences. All rights reserved.
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state department of transportation (DOT) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research.
Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 initiated an objective national highway research program using modern scientific techniques—the National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration (FHWA), United States Department of Transportation.
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DISCLAIMER
This material is based upon work supported by the FHWA under Agreement No. 693JJ32350025. Any opinions, findings, and conclusions or recommendations expressed or implied in this document are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors.
The Transportation Research Board does not develop, issue, or publish standards or specifications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications.
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The information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.
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COOPERATIVE RESEARCH PROGRAMS
CRP STAFF FOR NCHRP WEB-ONLY DOCUMENT 426
Monique R. Evans, Director, Cooperative Research Programs
Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program
Michael Brooks, Senior Program Officer
Dajaih Bias-Johnson, Senior Program Assistant
Natalie Barnes, Director of Publications
Brian Haefs, Associate Director of Publications
Kathleen Mion, Assistant Editor
NCHRP PROJECT 08-149 PANEL
Field of Transportation Planning – Area of Planning Methods & Processes
Preston J. Elliott, Tennessee Department of Transportation, Nashville, TN (Chair)
David Patrick Beardsley, Virginia Department of Transportation, Glen Allen, VA
Steven Alexander Bert, Institute for Transportation Research and Education, Raleigh, NC
Nate Evans, Maryland Department of Transportation, Baltimore, MD
Melissa Foreman, Federal Railroad Administration (FRA), Washington, DC
Megan Latshaw, Johns Hopkins University, Baltimore, MD
David Leingang, North Dakota Department of Transportation, Bismarck, ND
Nicholas Meltzer, Kittleson & Associates, Eugene, OR
Teresa Penninger, Oregon Department of Transportation, La Grande, OR
Jake Rueter, Minnesota Department of Transportation, Saint Paul, MN
Darren G. Buck, FHWA Liaison
Shannon H. Eggleston, AASHTO Liaison
Contents
Conduct of Research Report Organization
Scan of Applied Methods from Research and Practice
Development of Active Transportation Network Gap Typologies
Identify Gap Types and Locations for Study
Develop Quantified Estimates of Benefits
Develop Guide, Conduct of Research Report, and Implementation Memo
Chapter 3. Findings and Results
Behavior Change Technical Details
Health Benefits Estimation - Technical Details
Safety Benefits Estimation - Technical Details
Emissions Benefits Estimation - Technical Details
Enhanced Amenities Benefits Estimation - Technical Details
Chapter 4. Summary and Suggested Research
Tables
Table 1. Potential factions in gap analysis
Table 2. Emission benefits driven by mode shifts
Table 3. Summary of benefit calculations for gap-filling cycling projects
Table 4. Potential factors in gap analysis
Table 5. Three primary factors
Table 6. Sources and calculated estimates for percent change in bicycle travel
Table 7. Sources and calculated estimates for percent change in pedestrian travel
Figures
Figure 3. Conceptual model of safety benefits calculation.
Figure 4. Conceptual model of health benefit calculation.
NCHRP Web-Only Document 426 contains the Conduct of Research Report for NCHRP Project 08-149 and accompanies NCHRP Research Report 1149: Estimating Benefits of Closing Gaps in Active Transportation Networks: A Guide. Readers can read or purchase NCHRP Research Report 1149 on the National Academies Press website (nap.nationalacademies.org).
