BACKGROUND

A pedestrian can safely cross a street only if one of two conditions is met: either a vehicle comes to a full stop for the pedestrian or an adequate gap in traffic occurs that allows the pedestrian to cross without conflict. To assess such gaps, a pedestrian needs adequate visibility to make the decision.

Currently, evaluating sight distance for crosswalks is typically done from the perspective of a driver’s ability to stop for a pedestrian using stopping sight distance (SSD). However, limited guidance exists on how to evaluate pedestrian decision sight distance. Pedestrian sight distance can be assessed by modifying methodologies from the American Association of State Highway and Transportation Officials’ (AASHTO) A Policy on Geometric Design of Highways and Streets (hereafter the AASHTO Green Book) or Guide for the Development of Bicycle Facilities. However, criteria are not specified to determine the pedestrian crossing time in certain cases, such as Case B3 outlined in the AASHTO Green Book.

Research is needed to establish procedures and methodologies to support state departments of transportation in assessing and ensuring adequate pedestrian decision sight distance during the project development process.

OBJECTIVE

The objective of this project is to develop a framework for assessing sight distance for pedestrian crossings across various roadway contexts and pedestrian types.

Accomplishment of the project objective will require at least the following tasks.

TASKS

Task descriptions are intended to provide a framework for conducting the research. The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe work plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.

The sequencing of tasks and deliverables, such as technical memorandums or summary reports, shall be structured for delivery in quarterly progress report submissions in which specific deliverables are requested or proposed. A time estimation for each phase is presented below. However, the proposer may re-sequence the timeline according to their best decision-making.

Phase I - Planning

Task 1a.  Conduct a literature review of research on pedestrian sight distance and sight lines. This review should include exploring methodologies for assessing pedestrian sight distance, the characteristics and abilities of different pedestrian users (e.g., wheelchair users, children, older pedestrians), pedestrian gap acceptance for crossing roadways of various widths, emerging technologies, and existing or alternative sight distance models applicable to pedestrians. This task may include state and local regulations (e.g., California Daylighting Law), published and unpublished research conducted through the NCHRP and Federal Highway Administration, and other national, international, state, and pooled-fund sponsored research.

Task 1b. Conduct a practice scan and survey of transportation agencies to (1) examine how they incorporate pedestrian sight distance into their project development processes and (2) gather insights on their successes and lessons learned in implementing pedestrian sight distance methodologies. The survey questions and list of potential respondents need to be reviewed and approved by the NCHRP. 

Task 2. Analyze the information gathered in Task 1 to identify gaps and best practices in existing sight distance methodologies as they apply to pedestrians. This task shall include:

• Accommodation of diverse pedestrian characteristics, behaviors, and decision-making processes;
• Various crossing scenarios and traffic control conditions;
• Limitations of current vehicle SSD and intersection sight distance methodologies and assumptions (e.g., pedestrian crossing speed, object height, lateral pedestrian position) when applied to pedestrians;
• Environmental and infrastructural factors that affect pedestrian sight distance;
• Understanding used data, identifying limitations, and exploring data that has not been utilized but could support the new assessment framework;
• Integration of the Safe System Approach principles in pedestrian sight distance assessment; and
• Understanding how design speed, operating speed, posted speed limit, and statutory speed limit will affect the pedestrian sight distance assessment. 

Task 3. Develop a comprehensive research approach based on the findings from the literature review and identified gaps to be executed in Phase II to achieve the project objective. At a minimum, the proposed research approach shall describe the following proposed research activities:

• Identify scenarios in which pedestrian sight distance, sight lines, and pedestrian gap acceptance need to be assessed;
• Validate and adapt existing sight distance methodologies for pedestrian application or develop new methodologies in which gaps exist, incorporating perspectives from pedestrians, drivers, and practitioners; and
• Provide recommendations on variables used for sight distance assessments, such as pedestrian crossing speed, object height, lateral pedestrian position, and pedestrian reaction time, based on user characteristics and roadway contexts.

Task 4. Develop an annotated outline of the draft framework. 

Task 5. Prepare Interim Report No.1, which documents Tasks 1 through 4 and provides an updated work plan for the remainder of the research. The updated work plan must describe the process and rationale for the work proposed for Phase II.

Note: Following a 1-month review of Interim Report No. 1 by the NCHRP project panel, the research team will meet in-person with the panel to discuss the interim report. Work on Phase II of the project will not begin until authorized by the NCHRP.

For budgeting purposes, the proposer shall plan on having one in-person interim meeting in Washington, DC, with the panel. Costs for the in-person meeting venue and travel costs for NCHRP panel members to attend the meeting will be paid separately by NCHRP. 

Phase I shall be limited to 6 months, and the Phase I budget shall not exceed $80,000.

PHASE II – Execution and Deliverables

Task 6. Execute the work plan based on the approved Interim Report No.1.

Task 7. Prepare and submit the draft framework to the NCHRP for review and approval.

Task 8. Prepare draft language in a format and structure specified by AASHTO to conduct pedestrian sight distance assessments, which may be considered by AASHTO for the next update of the Guide for the Planning, Design, and Operation of Pedestrian Facilities (hereafter AASHTO Deliverable). The AASHTO Deliverable will be reviewed and approved by the NCHRP.

Task 9. Present the approved draft AASHTO Deliverable to relevant AASHTO committees for feedback and propose any necessary revisions to the NCHRP. The research team shall anticipate making two in-person presentations to at least two appropriate AASHTO committees, such as the Committee on Design and the Council on Active Transportation. Following the presentations, the research team shall revise the draft framework document and AASHTO Deliverable to incorporate feedback.

Note: The proposed budget should also include registration fees and travel costs for project team members to attend the AASHTO committee meetings.

Task 10. Prepare the final deliverables. At a minimum, the final deliverables shall include:

• A framework for assessing pedestrian sight distance;
• A final report documenting the entire research effort;
• The AASHTO Deliverable;
• A technical memorandum titled “Implementation of Research Findings and Products” (see Special Note J); and
• A presentation slide deck with presenter’s notes summarizing the project and clearly illustrating for the audience how the research can be applied in their organization.

Note: Following receipt of the draft final deliverables, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the final deliverables. 

SPECIAL NOTES

A. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs were revised in May 2024. Please take note of the new and revised text which is highlighted in yellow.

B. Proposals must be submitted as a single PDF file with a maximum file size of 10 MB. The PDF must be formatted for standard 8 ½” X 11” paper, and the entire proposal must not exceed 60 pages (according to the page count displayed in the PDF). Proposals that do not meet these requirements will be rejected. For other requirements, refer to chapter V of the instructions.

C. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs have been modified to include a revised policy and instructions for disclosing Investigator Conflict of Interest. For more information, refer to chapter IV of the instructions. A detailed definition and examples can be found in the CRP Conflict of Interest Policy for Contractors. The proposer recommended by the project panel will be required to submit an Investigator Conflict of Interest and Disclosure Form as a prerequisite for contract negotiations.

D. Proposals will be rejected if any of the proposed research team members work for organizations represented on the project panel. The panel roster for this project can be found at https://www.mytrb.org/OnlineDirectory/Committee/Details/7075. Proposers may not contact panel members directly; this roster is provided solely for the purpose of avoiding potential conflicts of interest.

E. Proprietary Products - If any proprietary products are to be used or tested in the project, please refer to Item 6 in the Information and Instructions for Preparing Proposals.

F. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively knowledgeable in the problem area. The project panel will recommend their first choice proposal considering the following factors: (1) the proposer's demonstrated understanding of the problem; (2) the merit of the proposed research approach and experiment design; (3) the experience, qualifications, and objectivity of the research team in the same or closely related problem area; (4) the plan for ensuring application of results; (5) how the proposer approaches inclusion and diversity in the composition of their team and research approach, including participation by certified Disadvantaged Business Enterprises; and, if relevant, (6) the adequacy of the facilities. A recommendation by the project panel is not a guarantee of a contract. The National Academy of Sciences (NAS - the contracting authority for the National Academies of Sciences, Engineering, and Medicine) will conduct an internal due diligence review and risk assessment of the panel’s recommended proposal before contract negotiations continue.

Note: The proposer's approach to inclusion and diversity as well as participation by Disadvantaged Business Enterprises should be incorporated in Item 11 of the proposal.

G. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the contract and the copyrights therein shall be owned by the National Academy of Sciences. The contractor and subcontractors will be able to publish this material for non-commercial purposes, for internal use, or to further academic research or studies with permission from TRB Cooperative Research Programs. The contractor and subcontractors will not be allowed to sell the project material without prior approval by the National Academy of Sciences. By signing a contract with the National Academy of Sciences, contractors accept legal responsibility for any copyright infringement that may exist in work done for TRB. Contractors are therefore responsible for obtaining all necessary permissions for use of copyrighted material in TRB's Cooperative Research Programs publications. For guidance on TRB's policies on using copyrighted material please consult Section 5.4, "Use of Copyrighted Material," in the Procedural Manual for Contractors.

H. The text of the final deliverable is expected to be publication ready when it is submitted. It is strongly recommended that the research team include the expertise of a technical editor as early in the project timeline as possible. See Appendix F of the Procedural Manual for Contractors Conducting Research in the Transportation Research Board’s Cooperative Research Program for technical editing standards expected in final deliverables.

I. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the Information and Instructions for Preparing Proposals. Proposals also should include a breakdown of all costs (e.g., wages, indirect costs, travel, materials, and total) for each task using Figures 5 and 6 in the brochure. Please note that TRB Cooperative Research Program subawards (selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB) must comply with 2 CFR 200 – Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards. These requirements include a provision that proposers without a "federally" Negotiated Indirect Costs Rate Agreement (NICRA) shall be subject to a maximum allowable indirect rate of 10% of Modified Total Direct Costs. Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $25,000 of each lower tier subaward and subcontract. Modified Total Direct Costs exclude equipment, capital expenditures, charges for patient care, rental costs, tuition remission, scholarships and fellowships, participant support costs and the portion of each lower tier subaward and subcontract in excess of $25,000.

J. The required technical memorandum titled “Implementation of Research Findings and Products” should (a) provide recommendations on how to best put the research findings/products into practice; (b) identify possible institutions that might take leadership in applying the research findings/products; (c) identify issues affecting potential implementation of the findings/products and recommend possible actions to address these issues; and (d) recommend methods of identifying and measuring the impacts associated with implementation of the findings/products. Implementation of these recommendations is not part of the research project and, if warranted, details of these actions will be developed and implemented in future efforts.

The research team will be expected to provide input to an implementation team consisting of panel members, AASHTO committee members, the NCHRP Implementation Coordinator, and others in order to meet the goals of NCHRP Active Implementation: Moving Research into Practice, available at http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP_ActiveImplementation.pdf

K. If the team proposes a Principal Investigator who is not an employee of the Prime Contractor, or if the Prime Contractor is proposed to conduct less than 50% of the total effort (by time or budget), then section five of the proposal should include: (1) a justification of why this approach is appropriate, and (2) a description of how the Prime Contractor will ensure adequate communication and coordination with their Subcontractors throughout the project.

L. All budget information should be suitable for printing on 8½″ x 11″ paper. If a budget page cannot fit on a single 8½″ x 11″ page, it should be split over multiple pages. Proposers must use the Excel templates provided in the Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs.

M. The National Academies have an ethical and legal obligation to provide proper attribution whenever material from other sources is included in its reports, online postings, and other publications and products. TRB will review all Cooperative Research Programs draft final deliverables using the software iThenticate for potential plagiarism. If plagiarized text appears in the draft final deliverable, the research team will be required to make revisions and the opportunity to submit future proposals may be affected.