U.S. Department 

Of Transportation 

Federal Highway 

Administration

400 Seventh St., S.W. 

Washington, D.C. 20590 

May 11, 1989 

Refer to: HNG-14/SS-10 

Mr. Ellis Britton 

HwyCom Corporation 

P.O. Box 2119 

Big Springs, Texas, 79720 

Dear Mr. Britton: 

This is in response to Mr. Red Lindsay’s February 15 letter to Mr. Thomas O. Willett 

requesting acceptance of your company’s 3-inch diameter fiberglass signpost system. 

You provided additional information on March 20 in response to our request. Together, 

these submissions include reports of two tests conducted by the Texas Transportation 

Institute, a specification for fiber-reinforced plastic (FRP) small sign supports, and 

supplementary information on component specifications. 

The two tests were conducted using the same 1,800-pound automobile (Honda Civic). 

The 19.7 m.p.h. test resulted in a change in velocity of 14.1 feet per second. The 63.0 

m.p.h. test resulted in a change in velocity of 2.9 fps. The tests were conducted in strong 

(S-1) soil in conformance with the requirements of NCHRP 230. The results are in 

compliance with the breakaway requirements of the AASHTO Standard Specifications 

for Structural Supports for Highway Signs, Luminaires and Traffic Signals, 1985. 

The sign post system consists of a 3-inch outside diameter FRP post composed of 

polyester resin (Owens-Corning Fiberglass) OCF E-440 Type Orthophthalic) and glass 

fiber reinforcement (OCF Roving 113, Yield T-30 or equivalent). The fiber-reinforced 

tube is manufactured by a process called “pultrusion”, whereby longitudinal and diagonal 

glass fibers are combined with a resin. A surface veil of woven glass fiber completes the 

1/8-inch thick wall of the tube. This FRP post is inserted into a 28-inch long, 3.10-inch 

to 3.125-inch inside diameter ceramic coated steel tube (wall thickness of 0.062 to 0.095 

inches) which has been flattened for 12 inches to prevent rotation. Self-tapping screws 

secure the post in place. 

Based on the above information this signpost system is acceptable for use on Federal-aid 

highway projects, should its use be proposed by a State. This acceptance is limited to 

breakaway characteristics of the system described above and does not cover its structural 

features. Further, we have determined that only one post should be allowed within an 8-
foot path. We note this system was only tested in the strong (S-1) soil described in 

NCHRP 230. Usually we would suggest that breakaway supports be tested in weak (S-2) 

soil. However, with the short foundation embedment specified for your support, we 

consider this additional testing unnecessary. On the other hand, users should be 

cautioned not to use the support in weak soil if to do so requires an increase in foundation 

embedment or other revision in the foundation, unless the revised design is tested. 

Presumably, Hwycom Corporation will supply potential users with sufficient information 

on structural design and installation requirements to ensure proper support performance. 

We anticipate that the States will require certification from Hwycom Corporation that 

materials furnished have chemistries, mechanical properties, and geometries 

approximately the same as those used in the tests and that the supports made from the 

materials will meet the breakaway requirements of the AASHTO specifications. 

Since the HwyCom FRP post and base system is a proprietary item, to be used in a 

Federal-aid project they: (a) it must be supplied through competitive bidding with 

equally suitable unpatented items; (b) the State highway agency certifies that it is 

essential for synchronization with existing highway facilities or that no equally suitable 

alternate exists; or (c) it is 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 (copy enclosed). 

 Sincerely yours, 

 L. A. Staron, Chief 

 Federal-Aid and Design Division 

Enclosures