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FHWA Home / Safety / Roadway Departure / Eligibility Letter HSSD/CC-88A

HSSD/CC-88A

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U.S. Department of Transportation

Federal Highway Administration

1200 New Jersey Avenue, SE.
Washington, DC 20590

June 1,2008

In Reply Refer To: HSSD/CC-88A

Dean Sicking, Ph.D., P.E.
Director, Midwest Roadside Safety Facility
University of Nebraska – Lincoln
527 Nebraska Hall
Lincoln, NE 68588-0529

Dear Dr. Sicking:

This is in response to your letter dated February 28, 2007, requesting Federal Highway Administration (FHWA) acceptance of the Sequential Kinking Terminal (SKT) and the FLared Energy Absorbing Terminal (FLEAT) using wood posts when connecting to the Midwest Guardrail System (MGS). FHWA Acceptance Letter CC-88, dated March 8, 2005, accepted these combinations based on testing with steel posts. You requested that we find these modified devices acceptable for use on the National Highway System (NHS) under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features.” We provided an informal opinion accepting this device on March 15, 2007, and have been working with you to finalize the drawings for this final acceptance package.

Introduction

The FHWA guidance on crash testing of roadside safety hardware is contained in a memorandum dated July 25, 1997, titled “INFORMATION: Identifying Acceptable Highway Safety Features.”

Two different anchor designs were used in the original MGS testing, a two post, ground line strut design and a large single post with a soil plate alternative. The upper parts of these designs were identical and Test 3-34 was conducted on the FLEAT with both anchor designs. Test FLEAT-5 used the two post and strut alternative while test FLEAT -7 used the single post anchor system. Videos, photos and reports on these tests were submitted with your original request for approval. At your request we only included the double post design in its approval letter.

Our original letter also indicated that both steel and wood post options were acceptable but you did not provide a drawing of the wood post option.

Findings

Based on prior testing discussed above we find the following terminal designs as shown in the enclosed drawings acceptable for use on the NHS under the range of conditions tested, when proposed by a State:

Please note the following standard provisions that apply to FHWA letters of acceptance:

 

Sincerely yours,

Signature of David A. Nicol

David A. Nicol
Director, Office of Safety Design
Office of Safety

Enclosures

Page last modified on June 2, 2009
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