Material Requirements for High-Tension Cable Barriers: A Guide (2025)
Chapter: 5 Topics for Specification/ Acceptance Plan
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Suggested Citation:
"5 Topics for Specification/ Acceptance Plan." National Academies of Sciences, Engineering, and Medicine. 2025. Material Requirements for High-Tension Cable Barriers: A Guide. Washington, DC: The National Academies Press.
doi: 10.17226/29173.
CHAPTER 5
Topics for Specification/Acceptance Plan
Through comprehensive analysis of literature, state surveys, and manufacturer interviews, the research team identified several HTCB topics that warrant national standardization. These priority topics are presented in Table 28.
Additionally, the team identified topics that are not currently suitable for national guidance because of various considerations. These topics are documented in Table 29.
Table 28. List of topics for inclusion in recommended HTCB Acceptance Plan.
| Topic |
|---|
| Specify cable (e.g., materials, pre-stretch, minimum breaking load) |
| Propose updates to AASHTO M 30 to cover increased breaking strength of the cable that is being supplied to HTCB manufacturers |
| Identify acceptable threaded fittings and turnbuckles |
| Critical review of driven post, driven socket, and sleeved concrete footer for line post installation |
| Standardize geotechnical analysis (e.g., boring details, boring frequency, factor of safety used, and geotechnical tests) for anchor foundations and line posts |
| Specify galvanizing for different components |
| Guidance on material property and testing documentation requirements |
| Common HTCB term abbreviations and definitions |
| Discuss design features for the systems |
| Discuss selection and placement criteria |
| Identify common materials |
| Discuss cable damage modes and thresholds for replacement |
| Critical review of methods for attaching cable fittings |
| Design considerations for mow strips (e.g., use, size, material) |
| Guidance on acceptable anchor foundation movement |
| Guidance on grading at anchor foundation locations |
| Guidance on acceptable levels of damage to line post footers and anchor foundations |
| Outlining of strategies for conducting independent lab certification of materials |
| Guidance on site design, particularly with regards to irregular grading which can cause changes in cable height |
| Guidance on what constitutes a “flat surface” |
| Ensure training increases the quality of workmanship |
| Develop a framework for pre-job and post-job training |
| Guidance on maintenance activities including cable tension checks |
| Guidance on frequency for requalifying installation and inspector personnel |
| Describe cable-to-post attachment and release mechanism (not specifying) |
| Describe post shape and materials (not specifying) |
| Guidance on design considerations of anchor foundations based on tension or soil condition |
| Guidance on frost heaving concerns |
Suggested Citation:
"5 Topics for Specification/ Acceptance Plan." National Academies of Sciences, Engineering, and Medicine. 2025. Material Requirements for High-Tension Cable Barriers: A Guide. Washington, DC: The National Academies Press.
doi: 10.17226/29173.
Table 29. List of deferred topics for recommended HTCB Acceptance Plan.
| Topic | Reason for Deferral |
|---|---|
| Add specification for acceptable stainless-steel cable. | Research was performed on this topic and is presented in Section 2.5.7. It has been excluded from the recommended HTCB Acceptance Plan since use of stainless-steel cable is not a high priority for the states, and use of stainless-steel cable would certainly require full-scale crash testing to receive an FHWA eligibility letter. |
| Guidance on steel reinforcement selection for anchor foundations. | Research was performed on this topic and is presented in Section 2.5.5. It has been excluded from the recommended HTCB Acceptance Plan since specification of reinforcing steel beyond what the states are already specifying is not a high priority for the states. |
| Specify the engineering properties for the various steel components of proprietary HTCB systems: posts, cable-end treatments, and other hardware. | The manufacturers of the proprietary HTCB systems have spent decades and millions of dollars developing and testing their designs to ensure satisfactory crash performance. Specifying the use of a different material for critical components of these systems may warrant retesting of the system. It is not appropriate to require such design modifications to proprietary systems. |
| Specify manufacturing specifications for components of all proprietary HTCB systems. | |
| Describe all material and material property testing for all materials used in HTCB systems. | This undertaking would be too large for the scope of this project. Additionally, through the literature review, survey of states, and manufacturer interviews no issues with improperly manufactured components were reported. |
| Design of MASH-approved HTCB to steel beam transition. | Design of systems is out of the scope of this project. |
| Design of MASH-approved HTCB system for installation on a 1V:3H slope. | Design of systems is out of the scope of this project. |
| Anchor foundation and post footer design. | The research team believes standardizing the geotechnical analysis will help to achieve more consistent anchor foundation and post footer design. |
| Discuss using used parts for repair. | The survey of states revealed limited use of used parts for repair of cable barrier systems. |
| Discuss design modifications for HTCB installed in curves. | This is a system- and site-specific issue that is best addressed by manufacturers and states. |
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