The National Academies

NCHRP 17-80 [Active]

Expansion of Human Factors Guidelines for Road Systems, Second Edition

  Project Data
Funds: $499,914
Staff Responsibility: Mark S. Bush
Research Agency: Battelle Memorial Institute
Principal Investigator: Dr. John L. Campbell
Effective Date: 11/9/2016
Completion Date: 8/9/2019


Published in 2012, NCHRP Report 600 was the first holistic complete release of the Human Factors Guidelines for Road Systems (HFG) Second Edition. The HFG is a relatively new roadway design resource that provides data and insights from the scientific literature on the needs, capabilities, and limitations of road users, including perception and effects of visual demands, cognition and influence of expectances on driving behavior, and individual differences including age and other factors. The HFG has 21 guideline chapters with a total of 90 guidelines. The HFG assists practitioners in safety, operations, and design in developing a greater understanding of road users’ capabilities and limitations and how these issues could be incorporated into day-to-day decision making. At its inception, it was envisioned that the HFG would be a living document where new guidelines would be developed as new human factors needs were identified and new research studies and data became available. It was also recognized that some topics could not be included in the initial HFG publication. For example, NCHRP Report 600 does not include chapters or content for roundabouts; multimodal issues such as pedestrians, bicycles, transit, freight; elderly mobility issues; relevance of the HFG to urban and rural applications; and application of the HFG in road safety audits. This material is frequently sought after by practitioners using the HFG. The Transportation Research Board Joint Subcommittee on Human Factors Road Design Guides, AND10(2), with the assistance of numerous other TRB Committees provided input to the HFG. Since the development of the 90 guidelines in the current HFG, additional research has been completed that will permit the addition of additional guidelines. During 2013, HFG application pilot tests were performed by the state departments of transportation in Arizona, Nevada, Idaho, Wisconsin, and Delaware. The tests were well received and addressed areas such as road safety audits, design, and diagnostic assessment of safety concerns. Concurrently, FHWA initiated the development of an HFG training course to be delivered by the National Highway Institute to state and local transportation departments and other organizations. The intent of these efforts is to promote the wide range of use of the HFG in safety analysis, diagnosis and evaluation as well as operational assessments. The AASHTO Highway Safety Manual (HSM) is also a key safety management and evaluation tool for state, regional, and local highway agencies including the planning, safety, design and traffic engineering professional community. The HSM was also developed largely through NCHRP research and the HSM First Edition was published in 2010. There is now ongoing NCHRP research to develop a proposed HSM Second Edition. The HSM and HFG promote improved safety for highway users and complement each other. While the HSM includes one section of a chapter on human factors, it provides only a broad scope, not specific guidelines. The HFG and HSM should be used together in conjunction with other design documents such as the AASHTO A Policy on Geometric Design of Highways and Streets (Green Book) and the FHWA Manual of Uniform Traffic Control Devices (MUTCD) and in coordination with the FHWA CMF Clearinghouse. Both the HFG and HSM when used together greatly enhance the efforts of highway engineers, traffic engineers, and planners to account for the road users’ needs in the design, operation, and management of roadways.


The objective of this research is to prepare a proposed Third Edition Human Factors Guidelines for Road Systems (HFG) based on updated and expanded guidelines. The proposed Third Edition HFG will synthesize and incorporate relevant ongoing and completed research, related documents, and user feedback in order to expand the scope and quality of the HFG to increase application and improve usability. The proposed Third Edition should be in a format and design similar to the Second Edition HFG, although recommendations for modification to format and style or design will be considered.


The research plan should build in appropriate checkpoints with the NCHRP project panel including, at a minimum (1) a kick-off web-enabled teleconference meeting to be held within 1 month of the contract’s execution date; (2) one face-to-face interim report review meeting at the end of Phase 1; and (3) any web-enabled teleconferences tied to panel review and/or NCHRP approval of any other interim deliverables deemed appropriate. The research plan should include, as a minimum, the following components as a suggested overall framework of the proposed research:
• Review the existing HFG for errors, inconsistencies, and duplications in content that need modification.
• Develop a plan to obtain user feedback to identify key criteria to be considered and detail acceptance criteria for content to be included in the Third Edition HFG.
• Identify gaps, and needed expansions or changes to current chapters including new additional content, chapters, and tutorials that are needed in the Third Edition HFG.
• Identify and assemble available research results and related HFG materials that should be considered for inclusion in the Third Edition HFG.
• Compile a list of broad-based issues and proposed changes for review by the NCHRP panel. These would include, as a minimum:
a) changes based on available research;
b) identification of critical gaps in knowledge or gaps in the available HFG materials that have not been addressed;
c) proposed work plan to fill those gaps either with materials expected from completed or ongoing research or with research to be conducted as part of this project;
d) recommended formatting changes to future editions of the HFG as compared to the existing Second Edition HFG.
e) recommendations on linkages in the Third Edition HFG to increase usability and coordination between related guidance resources such as the FHWA CMF Clearinghouse, AASHTO Highway Safety Manual, AASHTO Green Book, MUTCD, and other manuals; and
f) identification of an implementation strategy in order to maximize the application and use of the new HFG.
• Develop a comprehensive initial draft of the updated Third Edition HFG incorporating new HFG materials, expansions to current chapters, new added chapters, tutorials with case studies, or examples that illustrate the application of HFG methodologies.
• Incorporate recommended changes and comments from the NCHRP panel into a final draft Edition HFG suitable for NCHRP publication.
Phase 1 should include: (1) user feedback summary; (2) conduct of an initial literature review to identify potential guideline content; (3) a detailed work plan to identify and address relevant research gaps; (4) list of errors, gaps and modifications to current HFG text; (5) acceptance criteria for content to be included; (6) development of an outline, annotated table of contents, chapters, or framework of the proposed Third Edition HFG; (7) recommendations on potential implementation strategies to maximize the application and use of the new HFG; and (8) recommendations on any potential new print/electronic formats for the HFG to increase usability or direct cross referencing of other guidance documents such as the HSM, MUTCD, Green Book, or other widely used resources. The results should be incorporated into an interim report within 15 months of contract execution. An in-person meeting will be held with the project panel to discuss the interim report. SUBSEQUENT PHASES
Subsequent phases will involve executing the approved detailed work plan prepared in Phase 1 and preparing the final deliverables, including at a minimum: (1). A final report documenting the conduct of research that includes an executive summary and the research team’s recommendation of research needs and priorities for future related research and future HFG editions. As part of the final report, an appendix listing items considered but excluded from the Third Edition HFG and a justification of each item should be included. (2). A stand-alone final version of the Third Edition HFG. (3). A PowerPoint presentation with speaker notes describing the project background, objective, research method, findings, and conclusions suitable for use in a webinar. (4). A one- or two-sided page stand-alone summary document highlighting the HFG suitable for distribution/outreach as part of the implementation strategy. (5). A stand-alone technical memorandum titled “Implementation of Research Findings and Products”

Research in progress; phase 2 underway

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