1200 New Jersey Ave., SE

 Washington, D.C. 20590

Jun 13, 2013

FHWA:HSST:NArtimovich:sf:x61331:6/5/13

File: s://directory folder/hsst/nartimovich/HSST B114A_NPCG_LLC_formerly_Welch.docx

cc: HSST (Reader, HSA; Chron File, HSST; NArtimovich, HSST), BFouch, HSST 

In Reply Refer To:

HSST/B-114A

Mr. Ernest Knight

NPCG, LLC

P.O. Box Z

Carlisle, Iowa 50047

Dear Mr. Knight:

This letter is in response to your request for the Federal Highway Administration (FHWA) to 

review a roadside safety system for eligibility for reimbursement under the Federal-aid highway 

program. 

Name of system: DuroBlock Spacer

Type of system: Recycled Rubber Spacer Block for Guardrail

Test Level: NCHRP Report 350 Test Level 3

Testing conducted by: N/A

Date of request: March 27, 2013

Date of completed package: March 27, 2013

Decision

The following device is eligible, with details provided in the form which is attached as an 

integral part of this letter:

• DuroBlock Spacer Recycled Rubber Spacer Block for Guardrail

Based on a review of crash test results submitted by the manufacturer certifying the device 

described herein meets the crash test and evaluation criteria of the National Cooperative 

Highway Research Program (NCHRP) Report 350, the device is 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.

The FHWA, the Department of Transportation, and the United States Government do not 

endorse products or services and the issuance of a reimbursement eligibility letter is not an 

endorsement of any product or service.
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Requirements

To be found eligible for Federal-aid funding, roadside safety devices should meet the crash test 

and evaluation criteria contained in the NCHRP Report 350 or the American Association of State 

Highway and Transportation Officials’ Manual for Assessing Safety Hardware (MASH). 

Description

The device and supporting documentation are described in the attached form and previous 

FHWA Letter B-114 to Welch Products, Inc. dated March 27, 2003, copy enclosed for reference. 

We understand you have acquired the rights to manufacture the Welch offset block. 

Summary and Standard Provisions

Therefore, the system described and detailed in the attached form is eligible for reimbursement 

and may be installed under the range of conditions tested. 

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

• This finding of eligibility does not cover other structural features of the systems, nor 

conformity with the Manual on Uniform Traffic Control Devices.

• Any changes that may influence system conformance with NCHRP Report 350 

criteria will require a new reimbursement eligibility letter.

• Should the FHWA discover that the qualification testing was flawed, that in-service 

performance reveals safety problems, or that the system is significantly different from 

the version that was crash tested, we reserve the right to modify or revoke this letter.

• You are expected to supply potential users with sufficient information on design and 

installation requirements to ensure proper performance.

• You are expected to certify to potential users that the hardware furnished has the 

same chemistry, mechanical properties, and geometry as that submitted for review, 

and that it will meet the crash test and evaluation criteria of the NCHRP Report 350.

• To prevent misunderstanding by others, this letter of eligibility is designated as 

number B-114A 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. 
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• 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 FHWA does not become involved in issues concerning patent law. 

Patent issues, if any, are to be resolved by the applicant.

Sincerely yours,

Michael S. Griffith

Director, Office of Safety Technologies

Office of Safety

Enclosures