August 17, 2004
Refer to: HSA-10/SS-125
Mr. Tom Friend
P.O. Box 636
Hibbing, Minnesota 55746
Dear Mr. Friend:
Thank you for your email correspondence of July 7, 2004, requesting Federal Highway Administration (FHWA) acceptance of modifications to your company's breakaway mailbox supports for use on National Highway System (NHS). Accompanying your letter were drawings of the new Model #037 mailbox support. You requested that we find it acceptable for use on the National Highway System under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 "Recommended Procedures for the Safety Performance Evaluation of Highway Features."
Sign supports and mailbox installations should meet the guidelines contained in the NCHRP Report 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features". Requirements for breakaway supports are those in the American Association of State Highway and Transportation Officials' (AASHTO), "Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals".
The original Friend Town and Country Mailbox Support was found acceptable by the FHWA acceptance letter B-24 dated June 16, 1993. The acceptance was based on a comparison to the mailbox support designed and crash-tested by the Minnesota Department of Transportation. You also had an informal, live-driver test conducted at an impact speed of 62 mph.
The modifications to the Town and Country Mailbox are summarized below:
1) A single muffler clamp replaces the yoke clamps, used for height adjustments.
2) The extension U-post has been deleted.
3) Revised U-post driver, which is discarded upon installation.
We agree with your assertion that these modifications will have no significant affect on the breakaway performance of your company's mailbox support. Therefore, the modifications to your mailbox support described above and shown in the enclosed drawings for reference are acceptable for use as a Test Level 3 device on the NHS under the range of conditions as the similar mailbox support was tested, when proposed by a State.
Please note the following standard provisions that apply to FHWA letters of acceptance:
- Our acceptance is limited to the crashworthiness characteristics of the devices 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 device will require a new acceptance letter.
- Should the FHWA discover that the qualification testing was flawed, that in-service performance reveals unacceptable safety problems, or that the device being marketed is significantly different from the version that was crash tested, it reserves the right to modify or revoke its acceptance.
- 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 acceptance, and that they will meet the crashworthiness requirements of the FHWA and the NCHRP Report 350.
- To prevent misunderstanding by others, this letter of acceptance, designated as number SS-125 shall not be reproduced except in full. As this letter and the supporting documentation which support it become public information, it will be available for inspection at our office by interested parties.
- The Friend Town and Country Mailbox Support is a patented device and is considered "proprietary." When proprietary devices are specified by a highway agency for use on Federal-aid projects they: (a) must be supplied through competitive bidding with equally suitable unpatented items; (b) the highway agency must certify that they are essential for synchronization with 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. These provisions do not apply to exempt non-NHS projects. Our regulations concerning proprietary products are contained in Title 23, Code of Federal Regulations, Section 635.411, a copy of which is enclosed.
- This acceptance letter shall not be construed as authorization or consent by the FHWA to use, manufacture, or sell any patented device for which the applicant is not the patent holder. The acceptance letter is limited to the crashworthiness characteristics of the candidate device, 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.
/Original Signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety