The steel "auger in" foundations are not currently approved by SDDOT because of the uncertainty of the foundation design in accordance with AASHTO design guidelines. AASHTO does not have specific design guidelines relative to "auger in" foundations. The responsibility should lie with the manufacturers of these foundations to provide SDDOT sufficient design detail to verify that the design is consistent with current AASHTO design specifications.
The use of these anchors in highly corrosive soils has not been proven and would probably require long term testing. It is necessary for SDDOT to develop corrosion specifications using current ASTM and AASHTO specifications that would allow the anchors to be used in South Dakota soils.
Crash tests have already been conducted on light poles and signs attached to steel "auger in" foundations. The tests have proven that "auger in" foundations supporting breakaway devices performed acceptably with respect to the breakaway feature.
The foundations have been crash, corrosion, and load tested by various states and agencies. There is no doubt that the foundations can perform satisfactorily as a luminaire or sign support. However, the design of the foundations must be in accordance with current AASHTO design guidelines and consistent with SDDOT criteria.
submitted to SDDOT design methodology that indicates the "auger in" foundations meet current AASHTO and SDDOT design guidelines
submit their foundation design to AASHTO for approval and inclusion in "Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals."