The National Academies

NCHRP 22-51 [RFP]

Impact of Soil Stiffness on the Performance of Crash Testing and Roadside Safety

Posted Date: 7/28/2022

  Project Data
Funds: $250,000
Contract Time: 24 months
(includes 1 month for NCHRP review and approval of each interim report; and 3 months for NCHRP review and for contractor revision of the final report)
Authorization to Begin Work: 1/9/2023 -- estimated
Staff Responsibility: Christopher McKenney
   Phone: 202/334-2218
   Email: cmckenney@nas.edu
RFP Close Date: 9/16/2022
Fiscal Year: 2021


AASHTO’s Manual for Assessing Safety Hardware (MASH, 2016) contains the testing procedures used to evaluate various roadside safety features. MASH testing guidelines were intended to provide consistent and reproducible tests. One significant change in MASH is the use of standardized soil stiffness to provide consistency in the performance of safety barriers embedded in soil.  The development of stiffness criteria was based on testing in various U.S. test facilities utilizing soil criteria described in NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features, which did not specify soil types or the optimal hardware installations. The MASH specification for soil stiffness defines a minimum stiffness for the response of a standard W6x16 steel post surrogate to dynamic loads for a specified soil type and correlates this response to a static load test to be performed as part of each soil-based crash test.

Since the implementation of MASH testing, concerns with this new soil stiffness criterion have been noted. The first of these is the lack of a maximum stiffness limit. Highly stiff soils can negatively impact system performance, and there is concern that lack of an upper stiffness limit does not provide consistent testing between laboratories and various installations. Other potential issues relate to optimization of the current testing for identifying salient properties of a variety of soils utilized by various crash testing facilities.

Over the past few years, many crash tests have been performed on a variety of systems under MASH criteria. The opportunity to evaluate the efficacy of and potentially improve the new stiffness-based soil criteria is timely and critical to the continued improvement of roadside safety. Since MASH is the standard for evaluation of roadside safety devices, the research could affect state departments of transportation (DOTs) and other transportation agencies. Research is needed to review the current MASH soil specifications and evaluation procedures to ensure consistency in crash testing and develop proposed language for consideration by AASHTO to incorporate the research results in the next update of MASH.


The objective of this research is to evaluate the impact of soil stiffness on the performance of crash testing and roadside safety.


The research plan should (1) include a kick-off teleconference with the research team and NCHRP convened within 1 month of the contract’s execution; (2) address how the proposer intends to satisfy the project objective; (3) be divided logically into detailed tasks necessary to fulfill the research objective and include appropriate milestones and interim deliverables; and (4) incorporate opportunities for the project panel to review, comment on, and approve milestone deliverables.

Accomplishment of the project objective will require at least the following 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 review of literature and MASH testing data. The MASH testing data shall come from a cross-section of crash testing facilities. Review dynamic bogie and static instrumented post-test results performed during crash testing for each facility and correlate this to barrier performance.

Task 2. Review the test installation procedures and inspect the soil conditions at crash test facilities. Soil conditions shall include, but not be limited to, native and fill material soil type, width and depth of fill material, gradation, compaction, soil density, moisture content, and moduli.

Task 3. Identify sections of MASH that will be impacted by the results of the research findings. Develop proposed draft language for consideration by AASHTO to incorporate the research findings in the next update of MASH (herein called AASHTO Deliverable). The goal of the modifications is to more accurately reflect barrier performance during crash testing, with consideration given to soil conditions.

Task 4. Develop a plan to test the proposed AASHTO Deliverable. Submit, for NCHRP approval, a test plan for validation of potential modifications to MASH soil specifications and testing criteria.

Task 5. Prepare Interim Report No. 1 that documents the work completed in Tasks 1 through 4, and provides an updated and refined work plan for the remainder of the research no later than 6 months after the contract award date.  The updated 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, the research team will be required to meet in-person or online with the NCHRP project panel to discuss the interim report. This meeting is expected to be in-person and be held in Washington, D.C. Whether in-person or online, NCHRP will host the meeting and be responsible for any panel member costs to attend meeting. Work on Phase II of the project will not begin until authorized by the NCHRP.

PHASE II — Testing and Final Deliverables

Task 6. Execute Task 4 according to the approved Interim Report No. 1.  Based on the test results and data analysis, modify the proposed AASHTO Deliverable as needed.

Task 7. Submit final report and project deliverables. Project deliverables shall include: (1) a conduct of research report documenting the entire research effort; (2) the AASHTO Deliverable with draft language for the implementation of the findings for consideration by AASHTO in a future update of MASH; and (3) implementation plan (see Special Note I).

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.


A. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs were revised in May 2022. 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/6346. 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. 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.

I. 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.

J. 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 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.

K. 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.

Proposals must be uploaded via this link: https://www.dropbox.com/request/ttcPi5M51u12tqBhHZwt 
Proposals are due not later than 5:00 p.m. Eastern Time on 9/16/2022.

This is a firm deadline, and extensions are not granted. In order to be considered for award, the agency's proposal accompanied by the executed, unmodified Liability Statement must be in our offices not later than the deadline shown, or the proposal will be rejected.

Liability Statement

The signature of an authorized representative of the proposing agency is required on the unaltered statement in order for TRB to accept the agency's proposal for consideration. Proposals submitted without this executed and unaltered statement by the proposal deadline will be summarily rejected. An executed, unaltered statement indicates the agency's intent and ability to execute a contract that includes the provisions in the statement.

Here is a fillable PDF version of the Liability Statement. A free copy of the Adobe Acrobat PDF reader is available at https://www.adobe.com.

General Notes

1. According to the provisions of Title 49, Code of Federal Regulations, Part 21, which relates to nondiscrimination in federally assisted programs, all parties are hereby notified that the contract entered into pursuant to this announcement will be awarded without discrimination on the grounds of race, color, religion, sex, national origin, or disability.

2. The essential features required in a proposal for research are detailed in the current brochure entitled "Information and Instructions for Preparing Proposals". Proposals must be prepared according to this document, and attention is directed specifically to Section V for mandatory requirements. Proposals that do not conform with these requirements will be rejected.

3. The total funds available are made known in the project statement, and line items of the budget are examined to determine the reasonableness of the allocation of funds to the various tasks. If the proposed total cost exceeds the funds available, the proposal is rejected.

4. All proposals become the property of the Transportation Research Board. Final disposition will be made according to the policies thereof, including the right to reject all proposals.

5. Potential proposers should understand that follow-on activities for this project may be carried out through either a contract amendment modifying the scope of work with additional time and funds, or through a new contract (via sole source, full, or restrictive competition).

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