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U.S. Department of Transportation

Federal Highway Administration

400 Seventh St., S.W.
Washington, D.C. 20590


May 25, 2005

Refer to: HSA-10/WZ-208

Mr. Jeff Anderson
POCO Incorporated
42000 Van Born Road
Canton, Michigan 48188

Dear Mr. Anderson:

Thank you for your letter of March 8, 2005, requesting the Federal Highway Administration (FHWA) acceptance of your company's H-footprint portable sign stand as a crashworthy traffic control device for use in work zones on the National Highway System (NHS). Accompanying your letter were reports of crash testing conducted by Karco Engineering and video of the tests. 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." You provided additional documentation on April 7 and 12, 2005, in response to our requests.


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 support was made of two vertical supports of 1.5-inch square, 14 gage cold rolled steel (CRS) tubing ASTM 513A-500 Grade B, 96 inches long. The lower portion of each vertical support was reinforced with a 48 inch long section of 1 inch ID black pipe, ASTM A-500 Grade B, spot welded in place. The vertical supports were attached to the base by an 8 inch vertical piece of 2 inch square CRS tubing that was continuously welded to a horizontal foot.

The 72-inch long horizontal feet were 2 x 2 inch CRS angle of ASTM A-36 steel having a thickness of 0.25 inches. Each was held in place with a 35-pound sandbag at each end. The 48 x 48 inch sign panel was 5/8-inch thick plywood, fastened to the uprights with four 5/16-inch zinc plated bolts, 3.5 inches long. A 0.63-inch washer was placed under each bolt head and a 0.625 x 1.25 inch spacer was placed between the panel and the vertical supports. A warning light was mounted to a corner of the sign panel using a ½ inch x 13 bolt and a cup washer. The light was further stabilized with a "Z-plate" between the plywood and the light. The total height of the assembly was 128 inches and the total weight was 82 pounds.


Full-scale automobile testing was conducted on your company's devices. Two stand-alone examples of the device were tested in tandem, one end-on and the next placed six meters downstream turned at 90 degrees with the sign facing the car head-on, as called for in our guidance memoranda.

The tests are summarized in the table below.


NCHRP Report 350 Test 3-71

Test Report Number


Sign Stand Tested

90 degrees


Weight of Tested Stand

82 pounds (5/8 inch plywood panels weigh 36 pounds)

Mounting heights

60 inches

Flags? Lights?

One warning light on each sign

Mass of Test Vehicle

1732 pounds

Impact Speed

98.2 km/hr

Velocity Change

2.8 m/sec (limit is 5 m/sec)

Extent of contact

Edge of sign hit roof line

Flat of sign glanced off roof

Windshield Damage

Cracking, 2.5 inch deformation

No additional contact

Other notes

Roof depressed 3.5 inches



Moderate damage to the roof and windshield was caused by the end-on impact as the sign's leading edge struck the roof line and was deflected over the vehicle. In the end-on impact the stiffened legs retarded them from bending until the sign detached from the uprights and glanced flat off the roof. The 2.5-inch depression in the windshield caused by the end on impact is considered marginally acceptable. The results of the testing met the FHWA requirements and, therefore, the devices described above and detailed in the enclosed 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 the FHWA letters of acceptance:

Sincerely yours,

/original signed by/

John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety


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