To encourage state departments of transportation (DOTs) and hardware developers to advance hardware designs, the Federal Highway Administration (FHWA) and American Association of State Highway and Transportation Officials (AASHTO) collaborated on the development of the AASHTO Manual for Assessing Safety Hardware (MASH) implementation policy that includes sunset dates for various roadside hardware categories. The joint FHWA/AASHTO implementation plan for MASH devices (https://safety.fhwa.dot.gov/roadway_dept/countermeasures/reduce_crash_severity/docs/memo_joint_implementation_agmt.pdf) requires highway agencies to evaluate many different designs of permanent sign supports, breakaway poles, and work zone traffic control devices (herein called “Systems”). The FHWA/AASHTO implementation plan requires Systems installed on national highway systems after December 31, 2019 to comply with MASH 2016.
Highway agencies and manufacturers have been left in a situation where a significant number of Systems still need to be evaluated to comply with MASH. For each System, up to three full-scale crash tests need to be conducted on each variation, and these crash tests can be expensive. There are thousands of variations of Systems that the state DOTs utilize. The costs of these tests will fall directly on transportation agencies and the public. Because it is not feasible to test all possible combinations to MASH, there is a need to provide guidelines to aid state DOTs in selecting the appropriate testing protocols to evaluate the crashworthiness of Systems.
The objective of this research is to develop guidelines for implementation of, and propose modification, to the AASHTO MASH for sign supports, breakaway poles, and work zone traffic control devices, including examples to demonstrate the application of the proposed guidelines.
At the minimum, the research results shall include developing testing protocols that are validated by crash simulations and 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 the purposes of this research, a family of related devices is a set of similar devices within one of the three groups that shares the same critical characteristics controlling the crashworthiness.
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.
Task 1. Conduct a literature review of relevant research and current state of practice related to evaluation of Systems according to current MASH. The review shall include published and unpublished research conducted through the NCHRP; FHWA; and other national, international, state, and pooled-fund sponsored research.
Task 2. Synthesize the literature to identify the knowledge gaps for the implementation of the AASHTO MASH related to Systems. These gaps should be addressed in this research or in the recommended future research as budget permits.
Task 3. Propose analytical and testing programs, to be executed in Phases II and III, to achieve the project objectives.
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.);
- Present families with critical characteristics for the three groups in a matrix format;
- Develop a methodology to optimize crash testing for the crashworthiness for families of devices; and
- Conduct crash simulations.
Task 4. Identify areas of the current AASHTO MASH that will be modified and propose a preliminary outline for the guidelines.
Task 5. Prepare Interim Report No. 1 that documents Tasks 1 through 4 and provides an updated work plan for the remainder of the research. This report must be submitted no later than 4 months after contract execution. The updated plan must describe the process and rationale for the work proposed for Phases II though IV.
Note: Following a 1-month review of Interim Report No. 1 by the NCHRP, the research team will be required to meet in person with the NCHRP project panel to discuss the interim report. Work on Phases II though IV of the project will not begin until authorized by the NCHRP. Phase I shall be limited to $40,000.
PHASE II—Analytical Program
Task 6. Execute the analytical program according to the approved Interim Report No.1.
Task 7. Finalize the testing program work plan. Describe how the testing results will be utilized to achieve the research objective.
Task 8. Provide a detailed description of every chapter and section of the proposed guidelines and complete a sample chapter of the proposed guidelines selected by NCHRP. This chapter should be publication-ready.
Task 9. Prepare Interim Report No. 2 that documents the results of Tasks 6 through 8 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 I. The updated plan must describe the work proposed for Phases III and IV.
Note: Following a 1-month review of Interim Report No. 2 by the NCHRP, the research team will be required to meet in person with the NCHRP project panel to discuss the interim report, if necessary. Work on Phases III and IV of the project will not begin until authorized by the NCHRP. Phase II shall be limited to $110,000.
PHASE III—Testing Program and Guidelines Development
Task 10. Execute the testing program according to the approved Interim Report No. 2.
Task 11. Validate the analytical program based on the testing results and update accordingly.
Task 12. Develop the guidelines according to the approved outlines and propose modification to the AASHTO MASH.
Task 13. Develop the examples to demonstrate the application of the proposed modification.
Task 14. Prepare Interim Report No. 3 that documents the results of Tasks 10 through 13 no later than 12 months after approval of Phase II. The updated plan must describe the work proposed for Phase IV.
Note: Following a 1-month review of Interim Report No. 3 by the NCHRP, the research team will be required to meet in person with the NCHRP project panel to discuss the interim report, if necessary. Work on Phase IV of the project will not begin until authorized by the NCHRP.
PHASE IV—Final Products
Task 15. Revise the draft guidelines considering the NCHRP’s review comments.
Task 16. Prepare final deliverables including: (1) the AASHTO guidelines and the proposed modification to the AASHTO MASH, (2) a final report that documents the entire research effort, and (3) a stand-alone technical memorandum titled “Implementation of Research Findings and Products.” See Special Note E for additional information.
Note: Following receipt of the draft final report, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the revised final report. Phases III and IV shall be limited to $350,000.
STATUS: Research in progress