October 28, 1992
Refer to: HNG-14/SS-32
Mr. Volmer K. Jensen
Regional Federal highway Administrator (HEO-07)
Kansas City, Missouri
This is in response to your October 6 office memorandum to Mr. Thomas O. Willett requesting Federal highway Administration's acceptance of western red cedar for use in breakaway wood sign supports. The memorandum transmitted a letter from the Corps of Engineers (COE) indicating the strength of western red cedar is less than the strengths of wood commonly sold as "southern yellow pine", which is the type wood used in passing crash tests of modified 150-mm by 200-mm (6-inch by 8-inch) posts.
Based on the data supplied by the COE, we concur that 150-mm by 200-mm (nominal dimension) western red cedar posts with 75-mm (3 Inch) diameter holes drilled at 100-mm and 450-mm (4 inches and 18 inches) from the ground will be acceptable for use on Federal-aid highway projects. Western red cedar may also be used in lieu of southern yellow pine in other acceptable, crash tested small sign supports when requested by the COE or a highway agency.
Lawrence A. Staron, Chief
Federal-Aid and Design Division
Geometric and Roadside Design Acceptance Letter Number SS-32