May 18, 1989
Refer to: HNG-14/SS-11
Mr. Dragan Stevanovic
Manager, New Markets
Allied Tube and Conduit
16100 South Lathrop Avenue
Harvey, Illinois 60426
Dear Mr. Stevanovic:
In your April 10 letter to Mr. Hatton you requested Federal Highway Administration (FHWA) acceptance of a 14-gauge Qwik-Punch sign post set in an unreinforced 12-gauge foundation sleeve as meeting the breakaway requirements, based on the 1985 AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals, adopted by FHWA by Federal Register Notice dated January 5, 1989.
The cross-section dimensions of the posts for which you requested acceptance were not specified in our letter. However, in support of your request you cited out October 3, 1986, letter to Mr. Ronald C. Steininger in which we indicated acceptance of posts up to those having outside dimensions of 2.25 x 2.25 inches. Thus, we infer the maximum size post for which you are seeking acceptance is 2.25 x 2.25 inches x 14 –gauge.
One of the post designs accepted by out October 1986 letter included a 12-gauce, 2.5 x 2.5 x 30 inches anchor section reinforced with a 3/16-inch wall x 3 x 3x 18-inch sleeve at the top. This assembly is set 27 inches into the ground and the signpost is set 15 inches into the anchor. The post is held in position by a 3/8-inch, grade 2 bolt located approximately ½-inch below the top of the anchor assembly and passing through the sleeve, anchor, and post. Essentially your current request is for acceptance of removal of the 18-inch reinforcement sleeve from the anchor assembly. From our review of the test results upon which the original acceptance was based and those of single-section, direct-bury posts set 48 inches into the ground, also covered in our October 1986 acceptance letter, we see no reason to believe the removal of the reinforcement sleeve would adversely affect the breakaway performance of the support. Therefore, FHWA will find acceptable on Federal-aid projects, if proposed by a highway agency, 12-gauge post anchors holding 14-gauge sign posts in sizes up to 2.25 x 2.25 inches. In sizes of 2 x 2 inches x 14-gauge and smaller, a maximum of two such posts within a 7-foot path will also be acceptable.
L. A. Staron, Chief
Federal-Aid and Design Division
Federal Highway Administration
HED-1 HNG-1 HNG-10 HNG-14 Reader, 3212
Reader, 3128 Reader, 3206 File, 3128