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Subject: INFORMATION: Clarification of Roles and Responsibilities in Implementing the American Association of State Highway and Transportation Officials (AASHTO) / Federal Highway Administration (FHWA) Joint Implementation Agreement on the AASHTO Manual for Assessing Safety Hardware (MASH) Date: March 17, 2017
From Michael S. Griffith
Director, Office of Safety Technologies
In Reply Refer To:
To: Division Administrators
Directors of Field Services
Federal Lands Highway Division Engineers


Since the distribution of the AASHTO/FHWA joint implementation agreement for AASHTO MASH, we have received many questions on how FHWA and AASHTO are moving forward with the joint implementation agreement. This memo describes the different roles and responsibilities of FHWA and AASHTO since the transition from the National Cooperative Highway Research Program (NCHRP) Report 350 testing criteria to AASHTO's MASH criteria.


In 2015, roadway departure fatalities accounted for 18,695 highway fatalities. The implementation of the AASHTO MASH will help make roads safer and lessen the severity of roadway departure crashes. The AASHTO MASH, updated in 2016, provides AASHTO's first officially adopted crash-testing procedures for use in assessing roadside hardware. Until AASHTO MASH, NCHRP 350 – Recommended Procedures for the Safety Performance Evaluation of Highway Features, was the primary reference. FHWA accepted the responsibility for clarifying and providing guidance for the NCHRP 350 report. The NCHRP 350 report is now superseded by the AASHTO MASH.


In December 2015, the AASHTO/FHWA joint implementation agreement for AASHTO MASH was successfully balloted by AASHTO's Standing Committee on Highways and approved by FHWA. The agreement will help encourage the application of the newest and safest generation of roadside hardware. Per the agreement:

As noted above from the agreement, the AASHTO TCRS is responsible for developing and maintaining the evaluation criteria in AASHTO MASH. The FHWA will continue to provide technical assistance on roadside hardware to the AASHTO TCRS. Ultimately, the decision to make changes to the AASHTO MASH resides with AASHTO.

The FHWA will continue its role issuing letters of eligibility for roadside safety hardware that have been evaluated using AASHTO's MASH testing guidelines and criteria. Questions pertaining to the FHWA Federal-aid Eligibility Reimbursement Process or issuance of eligibility letters should be addressed to the FHWA Office of Safety.

Please note FHWA no longer issues new eligibility letters for roadside safety hardware tested under NCHRP 350. FHWA's Federal-aid eligibility letters are provided as a service to the States and are not a requirement for roadside safety hardware to be eligible for Federal-aid reimbursement. As stated in our eligibility letter, "eligibility for reimbursement under the Federal-aid highway program does not establish approval, certification or endorsement of the device for any particular purpose or use." It is the States' responsibility to determine whether or not to use a particular hardware device and how to use it for their particular situation.

AASHTO TCRS and FHWA will evaluate and monitor the availability of MASH-compliant devices and will revisit the implementation agreement as needed. Since the original implementation agreement was balloted by AASHTO, changes to the agreement will also be balloted by AASHTO and approved by FHWA.


Please share this memorandum with your State DOT. For more information about the AASHTO/FHWA Joint MASH Implementation Agreement, please visit https://safety.fhwa.dot.gov/roadway_dept/countermeasures/reduce_crash_severity/policy_memo_guidance.cfm. If you have any questions, please contact Will Longstreet at (202)366-0087 or Menna Yassin at (202)366-2833.

Page last modified on March 28, 2017
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