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FHWA Home / Safety / Roadway Departure / Safety Eligibility Letter

Safety Eligibility Letter CC-95B

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U.S. Department of Transportation
Federal Highway Administration

1200 New Jersey Ave. S.E.
Washington, D.C. 20590

April 7, 2011

In Reply Refer To: HSST/CC-95B

Mr. Geoff Maus
Chief Design Engineer
TrafFix Devices, Inc.
160 Avenida La Pata
San Clemente, CA 92673

Dear Mr. Maus:

This letter is in response to your request for the Federal Highway Administration (FHWA) acceptance of a roadside safety system for use on the National Highway System (NHS).

Name of system: Compressor Transition
Type of system: Transition from Attenuator to barrier or hazard
Test Level: National Cooperative Highway Research Program (NCHRP) Report Test Level 3
Testing conducted by: N/A
Date of request: August 31, 2010
Date initially acknowledged: August 31, 2010

You requested that we find this system acceptable for use on the NHS under the provisions of the NCHRP Report 350.

Requirements
Roadside safety devices should meet the guidelines contained in the Report 350. The FHWA memorandum, “ACTION: Identifying Acceptable Highway Safety Features” of July 24, 1997, provides further guidance on crash testing requirements of longitudinal barriers.

Decision:
The following device was found acceptable, with details provided below:

Description
The enclosed drawings show the Diverging Compressor Transition. This stiffened thrie-beam rail has a maximum flare of ten (10) degrees with respect to the sides of the compressor. It is designed to maintain the same relatively stiff structure of the end of the compressor for the distance needed to connect to a rigid object that is wider than the attenuator.

Crash Testing
No additional crash testing was conducted on this transition as it uses a structure similar to the side of the compressor attenuator.

Findings
We concur that the Diverging Compressor Transition may be used at a ten degree flare rate to connect to fixed objects that are wider than the rear of the compressor attenuator.

Therefore, the system described in the requests above and detailed in the enclosed drawings is acceptable for use on the NHS under the range of conditions the compressor attenuator was tested, when such use is acceptable to a highway agency.

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

 

Sincerely yours,

/* Signature of Michael S. Griffith */
Michael S. Griffith
Director, Office of Safety Technologies
Office of Safety

Enclosure

Page last modified on January 17, 2013.
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