Federal Highway Administration
400 Seventh St., S.W.
Washington, D.C. 20590
December 6, 2005
Refer to: HSA-10/WZ-39 #1
Mr. Peter Speer
Davidson Traffic Control Products
3110 70th Avenue East
Tacoma, Washington 98424
Thank you for your email of April 6, 2005, requesting the Federal Highway Administration (FHWA) acceptance of a modification to your company's T3B Plastic Type III Barricade as crashworthy traffic control devices for use in work zones on the National Highway System (NHS). Accompanying your earlier letters were a report from E-TECH Testing Services, Inc., detailed descriptions and drawings of each device, and videos of the crash tests. You requested that we find this barricade, with T3B 25.4mm x 210mm hollow plastic panels and plastic vertical members, acceptable for use on the NHS under the provisions of the National Cooperative Highway Research Program (NCHRP) Report 350 "Recommended Procedures for the Safety Performance Evaluation of Highway Features." Your present request was for the 8-foot wide version with PSST feet and uprights with the addition of a horizontal stabilizing PSST crossbar. This amended letter only addresses this variation.
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 were those lightweight devices which could be self-certified by the vendor, Category II devices were other lightweight devices which needed individual crash testing, Category III devices were barriers and other fixed or massive devices also needing crash testing, and Category IV devices were trailer mounted lighted signs, arrow panels, etc. 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.
The Perforated Square Steel Tube (PSST) Barricade using T3B panels is a Type III barricade using your plastic panels mounted on 1-3/4 inch PSST vertical uprights instead of your square thermoplastic vertical members. The FHWA acceptance letter WZ-39, originally signed June 29, 2000, found this barricade acceptable. It also accepted the substitution of 2-inch PSST horizontal skids with appropriate connection hardware to the uprights. Barricades up to 8 feet wide without auxiliary signs were also accepted.
Your present request is for the 8-foot wide version with PSST feet and uprights with the addition of a horizontal stabilizing PSST crossbar. We concur that this variation is within the range of Type III barricades that have been successfully tested and/or considered crashworthy. Therefore, your company's Type III barricades using up to 1-3/4 inch PSST uprights and crossbar of 12 or 14 gage PSST, and 2 inch PSST horizontal skids, with rails up to 8 feet long, are acceptable under the range of conditions tested for use on the NHS when requested by a State.
Please note the following standard provisions that apply to the FHWA letters of acceptance:
/Original Signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety
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