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U.S. Department of Transportation

Federal Highway Administration

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

August 29 , 2006

Refer to: HSA-10/SS-141

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

Dear Mr. Anderson :

Thank you for your letter of June 3, 2005, and email correspondence of June 14, 2006, requesting the Federal Highway Administration's (FHWA) acceptance of your company's ground-mounted sign support as a breakaway device for use on the National Highway System (NHS). Accompanying your correspondence were reports from Karco Engineering and video documentation of the testing. You requested that we find the Poco Incorporated Driven Sign Stand 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."

Testing of the supports was in compliance with the guidelines contained in the NCHRP Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. Requirements for breakaway supports are those in the American Association of State Highway and Transportation Officials' Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals.

The Poco Incorporated driven sign stand consists of two main parts: the sign panel and the support structure. The support structure is made up of two (2) vertical supports. These supports are composed of ninety-six inch (96") long by fourteen (14) gage wall thickness by one and one-half inch (1.5") square cold rolled steel tubing. Each support mast is stiffened with a 48" long section of nominal 1" schedule 40 steel pipe. This pipe is inserted into the 'bottom' portion of the mast and spot welded in place. Each mast is further drilled with four 3/8" diameter holes, placed 1" and 12" from each end.

The 5/8" thick plywood sign panel is attached to the masts with four (4) 5/16" diameter by 3-1/2" long hex head bolts and Nylok nuts. A 1/16" thick fender washer is placed between the head of each bolt and the face of the plywood and a 5/8" thick by 1-1/4" outside diameter by 3/8" inside diameter spacer is placed on the bolt between the back of the plywood and the mast.

The sign also has a Type A warning light (Empco-Lite Model 400) attached to one of the corners. This light is mounted with a 1/2"-13 bolt through a 9/16" hole, with a "cup washer" placed under the bolt head. The light is further held in position by the use of a "Z-bracket". The light contains at least one battery. The battery is placed in the outermost 'pocket' in the light case.

The masts are attached to 3 pound-per-foot 'U-channel' post sections, approximately forty-eight inches to sixty inches (48"-60") in length. These sections of 'U-channel' are embedded thirty-six to forty-eight inches (36"-48") in soil, with a minimum of twelve-and-one-half inches (12.5") protruding above ground.

Two (2) bolts are used to attach each mast to each 'U-channel' section. 5/16"-18 zinc plated bolts with Nylok nuts are placed through the holes drilled 1" and 12" from the bottom end of each mast, and through available holes in the 'U-channel' post section.

The total height of the assembly is approximately 128" and the total weight is approximately 95 pounds.


Full-scale automobile testing was conducted on your company's devices. The u-channel stubs were driven into standard soil. The complete devices as tested are shown in the enclosures.

Test Report


Mass (kg)


Occup. Impact
Speed (m/s)

Delta V













Occup. Speed: Occupant Impact Speed: Speed at which a theoretical front seat occupant will contact the windshield. In meters per second.
Delta V: Speed change of the test vehicle. In meters per second.


Damage was limited to dents to the bumper, grille, and hood, with windshield cracking occurring in only the high-speed test. There was a maximum deflection of 1 inch to the windshield. Velocity changes were all within acceptable limits. As the u-channel anchor posts broke off below the ground line there were no stubs remaining. The results of testing met the FHWA requirements and, therefore, the devices described above and shown in the enclosed drawings for reference are acceptable for use as Test Level 3 devices 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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