September 23, 1994
Refer to: HNG-14/SS-48
Mr. Kenneth L. Williams
639 Butler Street
Pittsburgh, Pennsylvania 15223
Dear Mr. Williams:
Thank you for your August 29 letter to Mr. William Weseman requesting acceptance of your company's "SAFE" foundation system for use on the Federal-aid projects. In our November 18, 1991, letter to MR. C.P. Tate of Foundations and Anchors Inc., a copy of which you provided with your letter, we stated that the foundation system does not have to be crash tested because the breakaway devices are not an integral part of the foundation. To demonstrate that the foundation provided a stable platform for mounting the breakaway device would be sufficient. We further stated that decisions regarding acceptability of a certain foundation type and size on an individual highway project are best made by the State or local highway agency based on it's analysis of the conditions at hand. The Federal Highway Administration does not review sign and luminaire support foundation designs for structural adequacy.
On July 15, 1992, we wrote to Mr. William G. Edwards of the A.B. Chance Company, indicating that company's helical screw foundations are acceptable as platforms for breakaway motorist aid callbox supports. Full-scale crash tests demonstrated that the slip-base device mounted on the Chance foundations performed as expected.
Your August 29 letter transmitted reports of static testing and computer projections that claim SAFE foundations are comparable to concrete foundations for providing structural support. There were no tests done specifically to assess the performance of SAFE foundations when subjected to dynamic loading as occurs in a vehicle collision with a sign support. However, it is our belief that breakaway couplings will perform as intended when used with SAFE foundations. Please not that this acceptance is limited to the ability of SAFE foundations to provide stable platforms for breakaway devices. Our acceptance does not cover the structural aspects that you requested. The SAFE foundations must be properly designed to meet the service load requirements of breakaway supports that would otherwise be suitable for mounting on breakaway couplings. We believe that determination remains with the highway agencies.
We are forwarding a copy of this letter to our regional offices so that they are aware of our acceptance of your company's SAFE foundations for use with breakaway sign support couplings, when requested by a State, on the National Highway System
Jerry L. Poston, Acting Chief
Federal-Aid and Design Division
Federal Highway Administration
HPD-1 HNG-1 HNG-10 HNG-14 Reader, 3212
Reader, 3206 Reader, 3128 File, 3128
RAs HHS-10 HNG-20 HSR-20
Geometric and Roadside Design Acceptance Letter SS-48