BACKGROUND 

Roadway departure crashes account for half of all fatalities every year, more than 18,000, with more than 5,000 fatalities resulting from head-on crashes. These crashes occur primarily on undivided, high-speed, rural roads with vehicles traveling in opposite directions, often separated only by a center line pavement marking and possibly a rumble strip. NCHRP Research Report 995: Guidelines for Treatments to Mitigate Opposite Direction Crashes provides guidelines for selecting appropriate safety countermeasures for opposite-direction crashes. The supporting research project, NCHRP Project 17-66, “Guidance for Selection of Appropriate Countermeasures for Opposite Direction Crashes,” found that center line buffer areas reduce opposite-direction crash fatalities significantly and are used around the United States. NCHRP Project 17-66 researchers developed crash modification factors for center line buffer areas of 2 ft, 4 ft, and 6 ft in width.

However, challenges arise during the implementation of center line buffer areas. Transportation agencies must often work within existing roadway pavement areas to implement low-cost safety countermeasures. In cases where the roadway cannot be widened to accommodate the center line buffer area, a practitioner must consider the roadway context and decide between narrowing the lanes or shoulders. Guidelines are needed to inform designers on the overall safety performance of various roadway cross sections with a center line buffer area. The aim is to determine which safety benefit between center line buffer areas and wider lanes and shoulders will guide the decision on where to reallocate pavement area.

Research is needed to develop guidelines and a tool to support the implementation of center line buffer areas so that practitioners can weigh the geometric and operational factors that affect the safety performance of center line buffer areas. 

OBJECTIVE

The objective of this project is to develop guidelines and a tool for the implementation of center line buffer areas, with a focus on rural two-lane highways. The project will evaluate the safety benefits of center line buffer areas while considering the reallocation of other cross-sectional elements and develop criteria for implementation.

Accomplishment of the project objective(s) 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 research 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.

PHASE I – Planning

Task 1. Conduct a literature review of relevant research, literature, and other sources regarding center line buffer areas related to the project objective. The review shall include published and unpublished research conducted through the NCHRP; the Federal Highway Administration (FHWA); and other national, international, state, and pooled-fund sponsored research.

Task 2.  Review state, county, local, federal land management agency, and Tribal policies, practices, and guidelines for implementing center line buffer areas from diverse geographic areas, climates, and contexts within the United States. 

Task 3. Conduct a critical analysis and synthesis of the literature and Task 2 results and identify knowledge gaps and opportunities related to the project objective. These gaps must be addressed in the final deliverables if the budget allows or in the recommended future research. Document findings from Tasks 1 through 3 in a technical memorandum.

Task 4. Develop a method to achieve the project objective to be executed in Phases II and III. At a minimum, the method shall formulate strategies to:

• Identify common roadway geometric and operational features that may influence the implementation of center line buffer areas, such as
  • Lane and shoulder width,
  • Shoulder pavement structure,
  • Roadway context,
  • Density of access points, 
  • Average daily traffic,
  • Sight distance,
  • Roadway users (e.g., trucks, pedestrians, bicycles, etc.),
  • Bicycle lanes,
  • Right-of-way,
  • Roadside conditions (e.g., curb, drainage, clear zone),
  • Embankment/cut slopes,
  • Posted speed limit (limited to 45 mph speed limit and above), 
  • Maintenance concerns (e.g., snow removal, work zone traffic control),
  • Delineation elements (e.g., rumble strips, flex-posts, pavement markings), and
  • Other cross-sectional elements;
• Evaluate the safety and operational trade-offs with various roadway cross-sectional configurations (e.g., center line buffer area, lane, shoulder widths); and
• Create guidelines and a non−web-based tool to aid practitioners in implementing center line buffer areas.

Task 5. Prepare an annotated outline of the draft guidelines and draft concept for a non−web-based tool (e.g., a table, matrix, spreadsheet).

Task 6. Prepare Interim Report No. 1, which documents Tasks 1 through 5 and provides an updated work plan for the remainder of the research.

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

Phase I shall be limited to 6 months.

Work on Phase II of the project will not begin until authorized by the NCHRP.

PHASE II – Method Development

Task 7. Execute the method in the approved Interim Report No.1. Summarize findings in a technical memorandum.

Task 8. Develop the draft guidelines.

Task 9. Develop the draft tool with a user guide and examples.

Task 10. Prepare a draft virtual presentation for the AASHTO Technical Committee on Roadside Safety.

Task 11. Prepare Interim Report No. 2, which documents Tasks 7 through 10 and provides an updated work plan for the remainder of the research. Interim Report No. 2 is due no later than 6 months before the end of the contract.

Note: Following a 1-month review of Interim Report No. 2 by the NCHRP project panel, the research team will meet with the panel in a virtual format to discuss the interim report. The research team will present the draft guidelines and tool during the interim meeting.

Work on Phase III of the project will not begin until authorized by the NCHRP.

PHASE III – Final Deliverables

Task 12. Prepare final deliverables, including:

• Guidelines for implementing center line buffer areas;
• An implementation tool for practitioners with a user guide and examples;
• A final report, including an executive summary, that documents the entire research effort;
• A PowerPoint presentation with speaker notes that summarizes the project and distinctly illustrates for the audience how the research can be applied in their organization;
• A virtual presentation of the guidelines and tool for the AASHTO Technical Committee on Roadside Safety; and
• A technical memorandum titled “Implementation of Research Findings and Products” (see Special Note J).

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/7080. 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.