October 12, 2004
Refer to: HSA-10/WZ-179
Dear Mr. Speer:
Thank you for your letter of March 19, 2004, requesting Federal Highway Administration (FHWA) acceptance of a revision to your company's T3BTM Type III Barricade as a crashworthy traffic control device for use in work zones on the National Highway System (NHS). You requested that we find the use of 2-inch "Quik-Punch" barricade feet or "skids" acceptable for use with this barricade 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 devices follows:
The T3B Barricade is a plastic, lightweight, portable Type III barricade. The T3B 25.4mm x 210mm (1 inch x 8.25) hollow plastic barricade panels are made from a specially formulated polyolefin plastic, and the vertical uprights are 44.5-mm (1.75 inch) square thermoplastic tubing extrusions. The support legs or "skids" are 14 ga, 50.8-mm (2 inch) square perforated galvanized mild steel tubing. One 150-mm (6-inch) tall PSST stub is welded to each support leg, and the vertical uprights are inserted into them. The T3B is available in heights between 1524 mm (60 inches) and 1829 mm (72 inches). Testing of your 2438-mm (8 foot) wide version of this barricade is detailed in the FHWA acceptance letter WZ-39 dated. June 29, 2000. The fasteners used were 7.94 mm (5/16") bolts with Nylock nuts and steel washers to attach panels to the uprights.
Your present request is to allow the substitution of 2 inch, 14-gauge Quik-Punch square tubes for the skids. The mounting hardware to support the plastic uprights will be essentially the same as that which was crash tested. As this substitution should not have a significant affect on the crashworthy performance of the barricade we concur in your request. Therefore, the T3BTM Type III Barricade modified with the 2 inch Quik-Punch skids is acceptable for use on the NHS under the range of conditions tested (except as modified by the Quik Punch skid), when proposed by a State.
|Barricade foot||14 ga Qwik-punch||2 x 2 x 60 inch w/ PSST Stub||12 lb|
|Upright||1 ¾ inch 14 ga PSST||1 ¾ x 1 ¾ x 60 inch||5 lb|
|T3B 8-inch panels||Thermoplastic||¾ x 8 ¼ x 96 inch||5.25 lb|
Please note the following standard provisions that apply to the FHWA letters of acceptance:
(Original Signed by John R. Baxter)
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety