Federal Highway Administration
400 Seventh St., S.W.
Washington, D.C. 20590
December 2, 2004
Refer to: HSA-10/WZ-177
Mr. Randy L. Warner
Protection Services, Incorporated
635 Lucknow Road
Harrisburg, Pennsylvania 17110
Dear Mr. Warner:
Thank you for your letter of August 23, 2004, requesting Federal Highway Administration (FHWA) acceptance of your company's vertical panel framed with 14-ga perforated square steel tubes as crashworthy traffic control devices for use in work zones on the National Highway System (NHS). Accompanying your letter was a drawing of the device. You requested that we find these devices acceptable for use on the NHS under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 "Recommended Procedures for the Safety Performance Evaluation of Highway Features."
The FHWA guidance on crash testing of work zone traffic control devices is contained in two memoranda. The first, dated July 25, 1997, titled "INFORMATION: Identifying Acceptable Highway Safety Features," established four categories of work zone devices: Category I devices are those lightweight devices which are to be self-certified by the vendor, Category II devices are other lightweight devices which need individual crash testing but with reduced instrumentation, Category III devices are barriers and other fixed or heavy devices also needing crash testing with normal instrumentation, and Category IV devices are trailer mounted lighted signs, arrow panels, etc. for which crash testing requirements have not yet been established. The second guidance memorandum was issued on August 28, 1998, and is titled "INFORMATION: Crash Tested Work Zone Traffic Control Devices." This later memorandum lists devices that are acceptable under Categories I, II, and III.
A brief description of the device follows:
The vertical panel frame is fabricated from 1-1/2" x 1-1/2" x 14 gauge, perforated Telspar tubing. The marker panel is 12" x 24" x .080" aluminum sheeted with 3M Diamond Grade prestriped sheeting. The base of the stand is made with 3 pieces of tubing, each piece being 16" long welded together in the configuration illustrated in the enclosed drawing with two splice plates attached to hold the 36"- 44" long upright and these two plates would function as a point of breakaway. These stands are to be placed in an 8 inch cut-out and the top of the panel must be 36" above the roadway.
No crash testing was conducted on this vertical panel design. However, the PSST framing materials and base connection details have been used in numerous Type III barricades and portable sign stands. Some lightweight dual-post PSST frames supporting rigid substrates have failed, but because of its size (36 inches from the pavement to the top of the panel) and the fact that the base will be sitting at the bottom of an 8 inch deep excavation adjacent to pavement, we concur that this device would likely meet the FHWA's evaluation criteria for work zone devices. Therefore, the device described above and detailed in the enclosed drawings are acceptable for use on the NHS under the conditions discussed in this letter, when proposed by a State.
Please note the following standard provisions that apply to FHWA letters of acceptance:
/Original Signed by Hari Kalla/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety
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