Safety Eligibility Letter WZ-100
Refer to: HSA-10/WZ-100
Mr. Bill Korman
Korman Signs, Incorporated
3029 Lincoln Avenue
Richmond, Virginia 23228
Dear Mr. Korman:
Thank you for your letter of May 23, 2002, requesting Federal Highway Administration (FHWA) acceptance of a number of your company's portable sign stands as crashworthy traffic control devices for use in work zones on the National Highway System (NHS). Accompanying your letter were reports of crash testing conducted by General Testing Services and video of the tests. 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.” On June 13, 2002, you met with Mr. Artimovich of my office and provided information in addition to that in the original request.
Introduction
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.
A brief description of your requests, including designation of the sign stands and the sizes and substrates you wish to use follows:
Request Number 1:
Stands:
SS560, SS560A, SS560E, SS560AE
Signs:
60x60 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrates:
0.100, and .080 Al., 5/8 or ½ Plywood, 6.35mm SP, Endurance, HDPE, 10mm CP,
Alpolic, Roll Up, 3-4mm ACS
Other:
With or without 48x30 or smaller supplementary panel using 10mm CP, Alpolic,
or Roll Up
With or without flags, light or ballast
Mounting Ht:
60 inches for diamond, 63 inches for rectangle, 21 inches for supplemental
Request Number 2:
Stands:
SS548, SS548A, SS548E, SS548AE, SS548C, SS548CE, SS548CA, SS548CAE
Signs:
48x60 or smaller Rectangle
Substrates:
Alpolic, 10mm CP, Roll Up
Other:
With or without flags, lights, or ballast
Mounting Ht:
21 inches
Request Number 3:
Stands:
SS548E, SS548AE, SS548CE, SS548CAE
Signs:
60x60 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrate:
Roll Up
Other:
With or without 48x30 or smaller supplementary panel using 10 mm CP, Alpolic,
or Roll Up
With or without flags, or ballast
Mounting Ht:
48 to 60 inches for diamond or rectangle, 21 inches for supplemental sign
Request Number 4:
Stands:
Type III Barricade
Signs:
60x60 or smaller Diamond or Square
60x48 or smaller Rectangle
25 Square Foot or smaller combination of signs
Substrate:
Alpolic
Other:
With or without ballast
Mounting Ht:
N/A
Request Number 5:
Stand:
SS1
Signs:
48x48 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrates:
.100 and .080 Al., 5/8 and 1/2 Plywood, Endurance, 6.35mm SP, HDPE,
10mm CP, Alpolic, Roll Up, 3-4mm ACS
Other:
With or without flags, or ballast
Mounting Ht:
13 to 14 Inches for diamond, 24 inches for rigid rectangle
13 to 28 inches for roll-up rectangle for 48x60 and 48x24 inch signs
Request Number 6:
None:
Deleted from original request. Repeated elsewhere in this submittal
Request Number 7:
Stands:
SS548, SS548AE, SS548CE, SS548CAE
Signs:
60x60 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrates:
10mm CP, Alpolic, Roll Up
Other:
With or without flags, light, or ballast
Mounting Ht:
19 to 21 inches
Request Number 8:
Stands:
SS548, SS548A, SS548C, SS548CA
Signs:
60x60 or small Diamond or Square
Substrate:
Roll Up
Other:
With or without flags, or ballast
Mounting Ht:
19 to 21 Inches
Request Number 9:
Stands:
SS548UC, SS548UCA, SS548UCX, SS548UCAX
Signs:
60x60 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrate:
Roll Up
Other:
With or without flags, or ballast
Mounting Ht:
21 Inches
Request Number 10:
Stands:
SS560UC, SS560UCA, SS560UCX, SS560UCAX
Signs:
60x60 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrate:
Roll Up
Other:
With or without flags, or ballast
Mounting Ht:
60 Inches
Request Number 11:
Stands:
SS548UCR, SS548UCRA, SS560UCR, SS560UCRA, SS548UCRX, SS548UCRAX, SS560UCRX,
SS560UCRAX
Signs:
60x60 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrate:
Roll Up
Other:
With or without flags, or ballast
Mounting Ht:
13 Inches
Request Number 12:
Stands:
SS548, SS548E, SS548A, SS548AE, SS548C, SS548CE, SS548CA, SS548CAE
Signs:
48x48 or smaller Diamond or Square
48x60 or smaller Rectangle
Substrates:
.080 Al, Endurance, 6.35mm SP, 10mm CP, HDPE, Alpolic, 3-4mm ACS
Other:
With or without flags, light, or ballast
Mounting Ht:
19 Inches
Abbreviations used in the above requests are:
Al.: Solid aluminum substrate
SP: Solid plastic (ABS) substrate
CP: Corrugated plastic
HDPE: Hollow core blow molded high density polyethylene waffle pattern substrate
Alpolic: 2 mm aluminum laminate composite substrate
ACS: Aluminum composite substrate/aluminum laminate 3 or 4 mm thick.
Enclosure #1 is a summary of the acceptances that this request embraces, with an indication of the mounting height of each sign that was tested and is to be considered for acceptance.
Testing
Full-scale automobile testing was conducted on your company's devices. Generally, two stand-alone examples of the device were tested in tandem, one head-on and the next placed six meters downstream turned at 90 degrees, as called for in our guidance memoranda. In some cases, different combinations of sign sizes and/or substrates were used on the two stands tested in order to qualify a broader range of hardware. The “worst case scenario” tests for the head-on and 90-degree impacts were discussed in advance with Mr. Artimovich. Enclosure #2 is a summary of the 37 crash tests conducted to support the requests. Enclosure #3 is another summary which relates the individual stands to the tests conducted as part of this submission, as well as to earlier FHWA letters of acceptance which support the individual request. Enclosure #4 is a summary of the product description and a glossary of terms used to describe the variations in your company's stands. Enclosure #5 contains a drawing of each stand, for reference.
Findings
Damage was limited to moderate cracking of the windshield in a number of tests, as noted in Enclosure #2, plus various damage to the bumper, hood, and roof of the test vehicles. There were no instances of passenger compartment penetration or intrusion.
The results of the testing met the FHWA requirements and, therefore, the devices described in the various requests above and detailed in the enclosed tables and drawings are acceptable for use on the NHS under the range of conditions 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 FHWA and NCHRP Report 350.
- To prevent misunderstanding by others, this letter of acceptance, designated
as number WZ-100 shall not be reproduced except in full. This letter, and
the test documentation upon which this letter is based, is public information. All
such letters and documentation may be reviewed at our office upon request.
- The may include patented components and if so are considered "proprietary." The use of proprietary work zone traffic control devices in Federal-aid projects is generally of a temporary nature. They are selected by the contractor for use as needed and removed upon completion of the project. Under such conditions they can be presumed to meet requirement "a" given below for the use of proprietary products on Federal-aid projects. On the other hand, if proprietary devices are specified for use on Federal-aid projects, except exempt, non-NHS 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. Our regulations concerning proprietary products are contained in Title 23, Code of Federal Regulations, Section 635.411, a copy of which is enclosed.
Sincerely yours,
Carol H. Jacoby, P.E.
Director, Office of Safety Design
Enclosure