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U.S. Department of Transportation

Federal Highway Administration

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

Refer to: HSA-10/WZ-222

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

Dear Mr. Anderson :

Thank you for your letter of December 1, 2005, requesting the Federal Highway Administration (FHWA) acceptance of your company's portable sign stand for supporting
4 x 5 foot rigid sign panels 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 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 three 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. Our new acceptance process was outlined in our memorandum "FHWA Hardware Acceptance Procedures – Category 2 Work Zone Devices" dated November 11, 2005.

A brief description of the devices follows:

The tested sign stand was made of 2 vertical masts of 1.5" x 1.5" square cold rolled steel (CRS) tubing, 14 ga wall thickness, and 96 inches long. The bottom portion of the vertical

masts is reinforced with a 48-inch long section of 1" ID black pipe, spot-welded in place. The footprint is made of 2 horizontal legs of 2" x 2" hot rolled steel angle. The angle has a thickness of 0.1875" and each leg is 72" long. The vertical masts slide inside a vertical stub, or socket, welded to each leg.

Each socket is constructed of 2" CRS tubing, with a wall thickness of approximately 3/16" (7 gage steel). The socket is welded to the base at all available intersections. The breakaway device, composed of a section of 1.5" x 1.5" x 14 gax 12" long CRS tubing (mast material without any 1" pipe inside) is welded to a section of 1.75" x 1.75" x 14 gax approximately 7.5" long Telespar perforated square steel tubing. The Telespar overlaps the 12" long section of tubing by approximately 3.5", and is welded around the perimeter. This then overlaps the sign mast by approximately 4". This subassembly is fastened to the bottom portion of the sign mast by placing a 5/16"-18 x 2.25" bolt through a corresponding hole drilled in the mast, approximately 1" from the end. This 'extension' to the mast sits in the socket on the foot.

The support structure is ballasted with two 35 pound sandbags placed on each leg. The vertical masts are further reinforced by an X-brace constructed of 1.25" x 1.25" hot rolled steel angle that is 0.125" thick and 66 inches long. The sign panel is a 48" x 60" reflective plywood panel, 5/8 inches thick. The panel is fastened to the vertical uprights by four 5/16" – 18 zinc plated bolts, 3.5" in length. A 1.25" diameter washer is placed under the bolt head and a 0.625" x 1.25" spacer is placed between the sign panel and the vertical mast. The total height of the assembly is 132" and the total weight is 134 pounds.

The CRS square tube and angle elements are ASTM A-36 steel, and the "black pipe" is ASTM A-500 Grade B.

Full-scale automobile testing was conducted on your company' devices. Two stand-alone examples of the device were tested in tandem, one oriented perpendicular and the next placed six meters downstream turned at 90 degrees to face head on, as called for in our guidance memoranda. In this case the perpendicular sign was placed first to avoid the situation where a sign struck head-on would lie on the vehicle and shield it from impact with the second sign.

The tests are summarized in the table below.

NCHRP Report 350 Test 3-71

Report Number


Sign Stand Tested



Mounting heights: bottom

1828 mm (6 feet)

Mounting heights: top

3353 mm (11 feet)

Flags? Lights?



Mass of Test Vehicle

799 kg test inertial weight

Impact Speed

103.4 kmh (64.3 mph)

95.2 kmh (59.2 mph)

Velocity Change

2.17 m/s

Extent of contact

Uprights made contact at roof line but signs hit roof only.

Windshield Damage

Minor overall cracking, with more cracking at point of impact of sign legs with roofline.

Other notes

Driver vision not impaired by the cracking.


Damage was limited to minor deformation of the roof, and windshield cracking. The signs in both the perpendicular and head-on impacts cleared the top of the windshield before contacting the roof. Impact of the uprights at the roof line above the windshield led to minor cracking overall with more modest cracking at the actual point of impact. There were no holes made through the glass, nor did the windshield separate from the frame. The results of the testing met the FHWA requirements and, therefore, the devices described in the various requests 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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