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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Safety Eligibility Letter SS-174

Hardware Type:
Sign Supports, Mailboxes, and Delineator Posts
Code:
SS-174
Date:
Testing Criteria:
NCHRP 350
Manufacturer:
Trinity Highway Products
Device Description:
Breakaway Sign Support Systems of Northwest Pipe Company
View PDF:
ss174.pdf (344.64 KB)

Safety Eligibility Letter SS-174 - Safety

Download Version
PDF [344 KB]

DOT logo
U.S. Department of Transportation
Federal Highway Administration

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

November 23, 2011

In Reply Refer To:
HSST/SS-174

T.J. Aslin
Trinity Highway Products, LLC
2525 Stemmons Freeway
Dallas, Texas 75207

Dear Mr. Aslin:

This letter is in response to your request for the Federal Highway Administration (FHWA) determination of eligibility for reimbursement under the Federal-aid highway program for highway safety products formerly manufactured by Northwest Pipe Company.

Name of system: Breakaway Sign Support Systems of Northwest Pipe Company
Type of system: Breakaway Sign Supports
Test Level: NCHRP Report 350 Test Level 3
Testing conducted by: NCHRP Report 350 Test Level 3
Date of request: October 10, 2011
Date initially acknowledged: November 3, 2011

You certify that the devices described herein meet the crashworthiness criteria of the National Cooperative Highway Research Program (NCHRP) Report 350. Based on the testing previously conducted you asked that we find the device(s) eligible for reimbursement under the Federal-aid highway program.  Eligibility for reimbursement under the Federal-aid highway program does not establish approval or endorsement by the FHWA for any particular purpose or use.

Decision:
The following devices are eligible, with details provided in the referenced letters:

  • All breakaway devices previously accepted for Northwest Pipe Company.

Requirements
Roadside safety devices should meet the guidelines contained in the NCHRP Report 350 or the American Association of State Highway and Transportation Officials' Manual for Assessing Safety Hardware (MASH).   The FHWA Memorandum "Identifying Acceptable Highway Safety Features" of July 25, 1997 provides further guidance on crash testing requirements of roadside safety features. Requirements for breakaway supports are those in the American Association of State Highway and Transportation Officials' Standard Specifications for Structural Supports for Highway Signs, Luminaries and Traffic Signals.

Discussion
On June 1, 2011, Trinity Highway Products, LLC purchased the Sign Support business segment from Northwest Pipe and has subsequently moved the manufacturing from Houston, TX to the Trinity facility located in Fort Worth, TX.  Trinity will begin producing product from this facility and you requested that the below referenced letters be transferred to Trinity Highway Products, LLC.  The current letters are:

Letter Number Date Principal product covered by the letter
SS-164 6/18/2010 Poz-Loc 10 inch square slip base system
SS-152 8/23/2007 PSST posts with 30-inch anchors
SS-150R 9/5/2008 Poz-Loc 8 inch square slip base system
SS-130 1/5/2006 Triangular slip base casting 16819
SS-128R 9/5/2008 Poz-Loc slip base casting 28339
SS-126A 11/24/2010 "Performance Post"
SS-126R 9/5/2008 PSST posts
SS-119 2/27/2003 (Correct letter numbering)
SS-117 11/13/2003 Poz Loc S-Q Post; PozLoc system with extended anchor; PozLoc breakaway mailbox system for snow regions
SS-88 8/15/2000 PSST posts
SS-65B 12/3/1997 Poz Loc Slip Base System
SS-65A 6/25/1997 Poz Loc Slip Base System and Poz Loc yielding system
SS-65 9/5/1996 Poz Loc Slip Base System
SS-01A 7/14/1986 Poz Loc anchor system
SS-Ol 5/13/1986 Poz Loc anchor system

These letters detail breakaway sign support systems that have been found crashworthy, and are eligible for reimbursement under the Federal-aid highway program.  As Trinity Highway Products now owns the sign support business segment of Northwest Pipe, these products will continue to be eligible if they meet the same specifications, dimensions, material chemistries and mechanical properties as the crash tested devices.

Findings                                                        
The systems detailed in the letters listed above continue to be eligible for reimbursement and should be installed under the range of conditions tested, when such use is acceptable to a highway agency.

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

  • This finding of eligibility is limited to the crashworthiness characteristics of the systems and does not cover their structural features, nor conformity with the Manual on Uniform Traffic Control Devices.
  • Any changes that may adversely influence the crashworthiness of the system will require a new letter.
  • Should the FHWA discover that the qualification testing was flawed, that in-service performance reveals unacceptable safety problems, or that the system being marketed is significantly different from the version that was crash tested, we reserve the right to modify or revoke this letter.
  • You will be expected to supply potential users with sufficient information on design and installation requirements to ensure proper performance.
  • You will be expected to certify to potential users that the hardware furnished has essentially the same chemistry, mechanical properties, and geometry as that submitted for review, and that it will meet the crashworthiness requirements of the FHWA and the NCHRP Report 350.
  • To prevent misunderstanding by others, this letter of eligibility is designated as number SS-174 and shall not be reproduced except in full.  This letter and the test documentation upon which it is based are public information.  All such letters and documentation may be reviewed at our office upon request.
  • This letter shall not be construed as authorization or consent by the FHWA to use, manufacture, or sell any patented system for which the applicant is not the patent holder.  The finding of eligibility is limited to the crashworthiness characteristics of the candidate system, and the FHWA is neither prepared nor required to become involved in issues concerning patent law.  Patent issues, if any, are to be resolved by the applicant.
  • Some of the Northwest Pipe devices are patented products and considered proprietary.  If proprietary systems are specified by a highway agency for use on Federal-aid projects, except exempt, non-NHS projects, (a) they must be supplied through competitive bidding with equally suitable unpatented items; (b) the highway agency must certify that they are essential for synchronization with the existing highway facilities or that no equally suitable alternative exists; or (c) they must be used for research or for a distinctive type of construction on relatively short sections of road for experimental purposes.  Our regulations concerning proprietary products are contained in Title 23, Code of Federal Regulations, Section 635.411
 

Sincerely yours,

/* Signature of Michael S. Griffith */

Michael S. Griffith
Director, Office of Safety Technologies
Office of Safety

Enclosures