Federal Highway Administration
400 Seventh St., S.W.
Washington, D.C. 20590
April 12, 2005
Refer to: HSA-10/WZ-205
Mr. Richard M. Heinz
Endless Visions, Incorporated
124 McAllister Street
Rushville, Illinois 62681
Dear Mr. Heinz:
Thank you for your letter of March 10, 2005, requesting the Federal Highway Administration (FHWA) acceptance of revisions to your company's J-4 Flagger's Workstation as a crashworthy traffic control device for use in work zones on the National Highway System (NHS). Accompanying your letter were drawings of the redesigned devices and a description of the changes. You requested that we find these devices 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."
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 as originally crash tested follows:
The J-4 Flagger's Workstation is a Category III portable work zone traffic control device. It is remotely operated by the flagger who is standing in a safer location off of the traveled way. The device consists of a 12-volt battery pack, motor system, push bar handle, 180 degree rotating fiberglass telescopic pole supporting a dual face sign supported by a small steel frame. The portable device is supported by four retractable outriggers when in use and caster wheels when moving from site to site. The outriggers are approximately 1030 mm by 1090 mm in the plan. The device is operated using a control box mounted on a 7.62-m extension cord. The overall height of the device was approximately 3.5 meters, and it weights approximately 93 kg. Details of the workstation are shown in the enclosed drawings for reference.
Full-scale automobile testing was conducted on the workstation. Two stand-alone examples of the device were tested in separate tests, one head-on and another turned at 90 degrees. Damage was limited to the front right corner of the test vehicle in the head-on impact with a very minor amount of floor pan deformation toward the occupants. The vehicle sustained moderate damage to the right front corner with a maximum exterior crush of 100 mm in the 90 degree impact. No deformation or intrusion into the passenger compartment resulted from the test. The FHWA acceptance letter WZ-119 was written to acknowledge compliance with our crashworthiness policies.
Your present request is to make the following changes to the J4 Flagger Workstation:
These modifications increase the weight of the J4 from 205 pounds to 260 pounds.
We concur in your assertion that the requested modifications are not likely to cause the J-4 Flagger Workstation to fail to meet the test criteria of the NCHRP Report 350, however we would recommend that you investigate the possibility of using lighter weight components to bring the weight back down towards the weight of the tested system. The device described above and shown in the enclosed drawings for reference is 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 the FHWA letters of acceptance:
/original signed by Harry W. Taylor/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety
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