BACKGROUND

Opposite-direction crashes, which involve a vehicle crossing into opposing lanes and impacting other vehicle(s) head on or in a sideswipe collision, account for more than 5,000 fatalities in the United States each year. These collisions most often occur on two-way, two-lane, high-speed rural roads, where opposing traffic is separated only by a center line pavement marking, sometimes supplemented with rumble strips. This type of roadway comprises approximately 69 percent of the national road network, totaling approximately 1.97 million miles.

NCHRP Research Report 995: Guidelines for Treatments to Mitigate Opposite Direction Crashes outlines several strategies for reducing opposite-direction collisions. Among them are center line buffer areas, which provide additional space between opposing traffic on undivided roads, and cable median barriers installed within the median of divided highways. For highways that do not have a median, a combined approach of installing barrier within a center line buffer area (hereafter referred to as center line barriers) may be effective. Only a limited number of existing sites in the United States have used this approach, and although these installations may not provide the full barrier deflection distance, a 2016 report titled Performance Evaluation of a Cable Median Barrier System on an Oregon Highway with a Narrow Median by Burns and Bell found this treatment effective in reducing opposite-direction crashes. 

Research is needed to evaluate the effects of center line barriers on roadway safety, operations, and maintenance. Additional study is also needed to investigate noteworthy practices and design considerations for implementing this treatment effectively.

OBJECTIVE

The objective of this research is to identify risk factors for opposite-direction crashes and investigate the safety, operational, and maintenance effects of center line barriers on previously undivided roadways. The research results will be used to prepare a guide with noteworthy practices, including safety performance and design considerations.

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 subaward 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 and other sources related to opposite-direction crashes on undivided roadways, and the use of center line barriers. 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. Conduct surveys to gather information regarding opposite-direction crashes, and current U.S. and international practices on the use of center line barriers. At a minimum, outreach shall include state departments of transportation (DOTs), relevant international agencies, and industry partners. The survey questionnaires and distribution lists must be reviewed and approved by the NCHRP prior to dissemination. It is expected that at least 50 percent of DOTs will respond to the survey.

Task 3. Synthesize and summarize the results of Tasks 1 and 2. Identify knowledge gaps and opportunities related to the project objective. Summarize findings in a technical memorandum.

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

• Identify risk factors associated with opposite-direction crashes, including but not limited to
  • Posted speed limit
  • Number of lanes
  • Lane and shoulder width
  • Annual average daily traffic (AADT)
  • Facility type
  • Roadway geometry
  • Time of day
  • Context classification (e.g., rural, suburban)
• Evaluate the safety performance of center line barriers and develop crash modification factors (CMFs) considering factors such as:
  • Crash severity
  • Crash type
  • Number of lanes
  • AADT
  • Buffer width
  • Barrier deflection into opposing lane(s)
  • Other safety treatments for opposite-direction crashes
• Identify and assess the operational effects of center line barriers, including but not limited to:
  • Operating speeds
  • Emergency management including evacuation routes and first responder activities
  • Property access
  • Provisions for passing
  • Wildlife connectivity
  • Non-motorized users
  • Sight distance
  • Marking and signing
• Assess maintenance considerations such as
  • Snow removal
  • Stormwater drainage
  • Repair and resurfacing
  • Temporary traffic control

Task 5: Prepare a comprehensive data collection plan that includes approaches for additional virtual outreach such as structured interviews, focus groups, or virtual workshops, as well as quantitative data collection. Include outreach materials (e.g., contact lists, interview questions) and an approach for collecting, archiving and sharing quantitative data. Identify potential partners for case studies. 

Task 6: Prepare a draft annotated outline of the guide.

Task 7. Prepare Interim Report No. 1 that documents Tasks 1 through 6, including a data archiving plan, and provides an updated and refined work plan for the remainder of the research. The interim report is due no later than 9 months after the subaward effective start date. The updated plan must describe the process and rationale for the work proposed for Phases II and III. 

Note: No more than $75,000 shall be allocated to the performance of Tasks 1 through 7.

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 in Washington, DC to discuss the interim report. Costs for the meeting venue and travel costs for NCHRP panel members to attend the meeting will be paid separately by the NCHRP. 

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

PHASE II – Method Execution

Task 8. Execute the data collection plan according to the approved Interim Report No. 1. Summarize the data collection efforts in a technical memorandum.

Task 9. Execute methods in the approved Interim Report No.1.

Task 10. Prepare the draft guide that includes at least two case studies. 

Task 11. Prepare Interim Report No. 2 that documents Tasks 8 through 10 and provides an updated and refined work plan for the remainder of the research, due no later than 8 months before the subaward expiration date. 

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.

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

PHASE III – Final Deliverables

Task 12. Prepare the final deliverables, including:

• A guide;
• A conduct of research report, including an executive summary, that documents all research and project efforts;
• Document(s) that support the CMFs to be considered by the CMF Clearinghouse;
• 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; and
• A technical memorandum titled “Implementation of Research Findings and Products” (see Special Note M).

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. At a minimum, the following items shall be incorporated into the Task 4 data collection plan. Proposers are strongly encouraged to provide additional thoughts to demonstrate a clear understanding of data needs and availability in support of successful research outcomes. 

• Data types and metrics such as crash history, geometry, barrier type, posted speed limit, operating conditions (e.g., AADT, speeds, time of day), etc.;
• Data inventory that already exists by source, years, granularity, access status, data restrictions (if applicable), and gaps; agencies or vendors to be contacted, with timing (initial outreach and scheduled follow-ups);
• Study windows suitable for crash analysis;
• Minimum sampling/coverage requirements appropriate to the source; and
• Quality Assurance and Quality Control (QA/QC) strategies addressing completeness, data coverage, and cross-source consistency checks, along with standard descriptive statistics to enable consistent comparisons.

B. The subawardee shall be responsible for (1) preparing all background and presentation material, and (2) all arrangements for the virtual workshops, focus groups, or structured interviews, including facilitation, note-taking, etc. The outreach plan portion of the data collection plan, including workshop materials and the potential attendee list, must be approved by the NCHRP.

C. The budget for risk factor analysis shall not exceed $50,000.

D. Revisions to the Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs are highlighted in yellow within that document.

E. 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 IV of the instructions.

F. 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 Subawardees. The proposer recommended by the project panel will be required to submit an Investigator Conflict of Interest and Disclosure Form as a prerequisite for subaward negotiations. 

G. 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/7241. Proposers may not contact panel members directly; this roster is provided solely for the purpose of avoiding potential conflicts of interest. 

H. 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.

I. 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; and, if relevant, (5) the adequacy of the facilities. A recommendation by the project panel is not a guarantee of a subaward. 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 subaward negotiations continue. 

J. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the subaward and the copyrights therein shall be owned by the National Academy of Sciences. The subawardee and lower-tier subawardees 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 subawardee and lower-tier subawardees will not be allowed to sell the project material without prior approval by the National Academy of Sciences. By signing a subaward with the National Academy of Sciences, subawardees accept legal responsibility for any copyright infringement that may exist in work done for TRB. Subawardees 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 Subawardees.

K. 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 Subawardees Conducting Research in the Transportation Research Board’s Cooperative Research Program for technical editing standards expected in final deliverables.

L. 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 selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB. TRB Cooperative Research Program subawards 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) or audited indirect rates shall be subject to a maximum allowable indirect rate of 15% of Modified Total Direct Costs (de minimis rate). Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $50,000 of each lower-tier subaward. 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 in excess of $50,000.

M. 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

N. If the subawardee 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 subawardee will ensure adequate communication and coordination with their lower-tier subawardees throughout the project.

O. 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. 

P. 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.