Refer to: HSA-10/WZ-157
Mr. Chase Gauger
7700 Austin Avenue
Skokie, Illinois 60077
Dear Mr. Gauger:
This is in response to your letter of June 11, 2003, requesting Federal Highway Administration (FHWA) acceptance of variations to your company's Narrowcade and Plasticade Barricades as crashworthy traffic control devices for use in work zones on the National Highway System (NHS). These barricades were originally crash tested by the Texas Transportation Institute and found acceptable by FHWA via WZ-14 on May 28, 1999. 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." In summary, the modifications to the Narrowcade will be acceptable, but the Plasticade modification for use as a sign holder must be crash tested.
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 must 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.
You requested that the Narrowcade be found acceptable with the following modifications as shown on the enclosed drawings by Maricopa County, Arizona:
The cable straps are intended to keep the legs of the Narrowcade spread with a footprint in the range of 28 to 30 inches. The retaining clips and flexible plastic panel are requested to that the direction of the stripes can be changed depending on the position of the device.
The modifications of the Narrowcade described above and detailed in the enclosed drawings should not have any detrimental effect on the crash performance of the Narrowcade. Therefore, these modifications are acceptable for use on the NHS under the range of conditions tested, when proposed by a State.
You also requested modifications to the Plasticade barricade that would allow it to support a 36x36-inch rigid sign. As there has been no crash testing of type II barricades supporting signs, we must decline this request. We understand that Maricopa County is interested in funding a crash test for this combination device. We would appreciate it if you would inform the County that FHWA, Office of Safety is willing to work with them to establish the appropriate test matrix for this device, including the precise details of the test article to ensure maximum applicability from the testing.
Please note the following standard provisions that apply to FHWA letters of acceptance:
Michael S. Griffith
Acting Director, Office of Safety Design
Office of Safety