Manual for Assessing Safety Hardware (MASH)

SUMMARY

In issuing Federal-aid eligibility letters for roadside safety hardware, FHWA currently makes determinations of continued eligibility for modifications to devices tested to the National Cooperative Highway Research Program Report 350 (NCHRP 350). To facilitate the implementation of the Manual for Assessing Safety Hardware (MASH), FHWA intends to discontinue issuing eligibility letters for requests received after December 31, 2015 for modified NCHRP 350-tested devices that do not involve full-scale crash testing to the MASH. Modifications to NCHRP 350-tested devices that have, in the past, been based on engineering analysis or finite element modeling will no longer receive FHWA eligibility letters.

Effective January 1, 2016, all changes to NCHRP 350-tested devices will require testing under MASH in order to receive a Federal-aid eligibility letter from FHWA.

  • For contracts on the National Highway System with a letting date after the dates below, only safety hardware evaluated using the 2016 edition of MASH criteria will be allowed for new permanent installations and full replacements:
    • December 31, 2017: w-beam barriers and cast-in-place concrete barriers
    • June 30, 2018: w-beam terminals o December 31, 2018: cable barriers, cable barrier terminals, and crash cushions
    • December 31, 2019: bridge rails, transitions, all other longitudinal barriers (including portable barriers installed permanently), all other terminals, sign supports, and all other breakaway hardware
  • Temporary work zone devices, including portable barriers, manufactured after December 31, 2019, must have been successfully tested to the 2016 edition of MASH. Such devices manufactured on or before this date, and successfully tested to NCHRP Report 350 or the 2009 edition of MASH, may continue to be used throughout their normal service lives.
  • Regarding the federal-aid eligibility of highway safety hardware, after December 31, 2016:
    • FHW A will no longer issue eligibility letters for highway safety hardware that has not been successfully crash tested to the 2016 edition of MASH.
    • Modifications of eligible highway safety hardware must utilize criteria in the 2016 edition of MASH for re-evaluation and/or retesting.
    • Non-significant modifications of eligible hardware that have a positive or inconsequential effect on safety performance may continue to be evaluated using finite element analysis.

INDOT REVISIONS TO DATE

The INDOT Standards Committee approved the Midwest Guardrail “W-beam” system in the meeting held May 18, 2017. The MGS guardrail is similar to the currently used “strong post w-beam. The differences between the two types are:

  • The MGS w-beam has a top rail height of 31” vs. 27 ¾“ for the strong-post w-beam.
  • The MGS w-beam has a mid-span splice vs. a splice at the post for the strong post w-beam.
  • The MGS w-beam uses a 6-ft post with an embedment depth of 3’-4”. INDOT currently uses a 7-ft post with 4’-7 ¼” embedment), but a 6-ft post is acceptable.

The two systems use the same w-beam rail section and assembly bolts, may use either a steel or wood post, and may use either a wood or composite blockout. The MGS w-beam system will maintain the same 1’-5” typical section (front face of rail to back face of post) as current strong-post w-beam guardrail system.

The effective date for the Recurring Plan Detail (RPD) is January 1, 2018. Contractors should carefully review contract information books for this detail.

INDOT is still working on a standard for cast-in-place concrete median barrier wall (December 31, 2017 deadline). ICI provided feedback to INDOT concerning potential changes to the standard wall dimensions included the current INDOT Standard Drawings E-602-CCMB-01 through 04. INDOT informed ICI that the current wall standard dimensions need to be raised to meet MASH requirements. The raised height is due to an increase in average vehicle bumper elevation. Current INDOT standard overall wall heights are 33 and 45 inches. INDOT has suggested that the minimum wall height could increase to 38 inches.

Contractors reported that they currently have the ability to install wall at a height of 45 inches. One suggestion to INDOT is to eliminate the 33 inch standard and only specify the 45 in. that would accommodate an increase to 38 inch height suggested? Contractors added that current forms would have to be modified if a 38 inch standard height is adopted. If the dimensions of the lower section or haunch change, contractors will have to purchase costly new forms and associated vibrators. The costs were reported to be significantly higher for the hydraulically controlled forms for unequal haunch elevation installation (differing surface elevations on either side of the median wall).

ICI will continue to work with INDOT on revisions and publish updates they become available.

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