BACKGROUND
Historically, roadside safety features have been subjected to crashworthiness evaluations using a variety of impact test specifications and/or guidelines. The implementation of American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) has left state departments of transportation (DOTs) and manufacturers in a situation where a significant number of breakaway poles, sign supports, and work zone traffic control devices (herein called “Systems”) need to be evaluated for MASH compliance. The development of robust surrogate test vehicles, with an ability to largely capture vehicle deformation and penetrations as well as accurate system behavior, would reduce crash-testing costs and promote greater innovation for new products for manufacturers and DOTs. There is a need to provide a guide to aid in selecting the appropriate surrogate test vehicles and testing protocols to evaluate the crashworthiness of Systems.
OBJECTIVE
The objective of this research is to develop a guide for the implementation of surrogate test vehicles, including pendulums and bogie vehicles, for evaluation of Systems for MASH compliance and propose modifications to the AASHTO MASH for sign supports, breakaway poles, and work zone traffic control devices.
At the minimum, the research results shall include the design and development of surrogate test vehicles, testing protocols, and validation based on simulation and laboratory testing for families of related devices within the following three groups: (1) sign supports, (2) breakaway poles, and (3) work zone traffic control devices. For this research, a family of related devices is a set of similar devices within one of the three groups that share the same critical characteristics controlling crashworthiness.
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 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 comprehensive literature review of relevant research and current state of practice related to the evaluation of Systems using surrogate test vehicles. The review shall include published and unpublished research conducted through the NCHRP; Federal Highway Administration (FHWA); and other national, international, state, and pooled-fund sponsored research.
Task 2. Synthesize the literature to identify the knowledge gaps related to the use of surrogate test vehicles in evaluating Systems for MASH compliance. These gaps should be addressed in this research or the recommended future research as budget permits.
Task 3. Propose a methodology for developing surrogate test vehicles models, to be executed in Phase II. At a minimum, the proposed methodology shall consider the following:
- MASH 2016 bogie vehicles pertaining to a passenger car and a pickup truck;
- Test matrices and conditions, test installation, and the proper applications and limitations of the surrogate test vehicles;
- Critical behaviors and failure modes that can be evaluated under impact testing with surrogate bogie vehicles and/or a pendulum mass; and
- Test evaluation criteria and test documentation.
Task 4. Propose analytical and testing programs, to be executed in Phases III and IV, to achieve the project objective. At a minimum, the analytical program shall include the following steps:
- Define the critical characteristics that control the crashworthiness for families of devices within the three groups (e.g., critical characteristics for a family may include different heights, substrate materials, mass, breakaway mechanism, etc.);
- Develop a test matrix to conduct crash simulations using the developed surrogate test vehicles for families of devices within the three groups; and
- For the simulation validation, compare the results with the available results from full-scale vehicle crash simulation and field tests conducted by FHWA, NCHRP, and other projects.
Task 5. Propose a preliminary outline for the guide and identify areas of the current AASHTO MASH that will be modified.
Task 6. Prepare Interim Report No. 1 that documents Tasks 1 through 5, includes the data archiving plan, and provides an updated work plan for the remainder of the research. This report must be submitted no later than 6 months after contract execution. The updated plan must describe the process and rationale for the work proposed for Phases II through V.
PHASE II— Develop Surrogate Test Vehicles Models
Task 7. Execute Task 3 according to the approved Interim Report No.1. The developed models shall include the design document with 3D CAD details for fabrication in Phase IV.
Task 8. Finalize the analytical program work plan. Describe how the analytical results will be utilized to achieve the research objective.
Task 9. Prepare Interim Report No. 2 that documents the results of Tasks 7 and 8 and provides an updated work plan for the remainder of the project. This report is due no later than 6 months after approval of Phase I. The updated plan must describe the work proposed for Phases III through V.
PHASE III—Analytical Program
Task 10. Execute the analytical program according to the approved Interim Report No. 2. Finalize the design of the surrogate test vehicles and the validation processes.
Task 11. Finalize the testing program work plan to fabricate and test the developed surrogate test vehicles. Describe how the testing results will be utilized to achieve the research objective.
Task 12. Provide a detailed description of every chapter and section of the proposed guide and complete a sample chapter of the proposed guide selected by NCHRP. This chapter should be publication-ready.
Task 13. Prepare Interim Report No. 3 that documents the results of Tasks 10 through 12 and provides an updated work plan for the remainder of the project. This report is due no later than 10 months after approval of Phase II. The updated plan must describe the work proposed for Phases IV and V.
PHASE IV—Testing Program and Guide Development
Task 14. Execute the testing program according to the approved Interim Report No. 3.
Task 15. Validate the analytical program based on the laboratory testing results and update the design of the developed surrogate test vehicles accordingly.
Task 16. Develop the guide according to the approved outlines and propose modifications to the AASHTO MASH.
Task 17. Prepare Interim Report No. 4 that documents the results of Tasks 14 through 16 no later than 18 months after approval of Phase III. The updated plan must describe the work proposed for Phase V.
PHASE V—Final Products
Task 18. Revise the draft guide, proposed modification to the AASHTO MASH, and the design of surrogate test vehicles with 3D CAD details considering the NCHRP’s review comments, and submit no later than 1 month after approval of Phase IV.
Task 19. Prepare final deliverables including (1) the guide and the proposed modification to the AASHTO MASH, (2) the design of surrogate test vehicles with 3D CAD details, (3) a final report that documents the entire research effort, and (4) a stand-alone technical memorandum titled “Implementation of Research Findings and Products.” See Special Note F for additional information. The draft deliverables are due no later than 3 months after approval of Phase IV.
STATUS: Research in Progress
