December 9, 2003
Refer to: HSA-10/CC75B
Owen S. Denman, P.E.
Barrier Systems, Incorporated
180 River Road
Rio Vista, California 94571-1208
Dear Mr. Denman:
In your November 3 letter, you requested formal Federal Highway Administration acceptance of a “family” of crash cushion designs called the Universal TAU-II Crash Cushion System. The primary difference from the original parallel-sided TAU-II designs was the introduction of variable-width diaphragms that result in a 5-degree outward flare of the attenuator side panels to allow direct shielding of hazards up to 2.6 m (8.5 feet) in width. Included with your letter were copies of Safe Technologies, Incorporated, October 2003 report, “NCHRP Report 350 Crash Test Report – Barrier Systems, Incorporated. Wide TAU-II Crash Cushion System” and CD-ROMs and VHS tapes of the certification tests that were run. In preliminary discussions with members of my staff, it was mutually agreed that selected tests on both the narrowest and widest versions of the wide TAU-II would be sufficient to accept less critical configurations of these two designs as also meeting NCHRP Report 350 evaluation criteria. The two configurations tested and the summary test results are shown in Enclosures 1 through 7.
Based on these test results, I agree that the TAU-II configurations shown in Enclosure 8 may be considered acceptable for use on the National Highway System with the following caveats:
/Original signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety
cc: HSA-10 (Reader, HSA-1; Chron File, HSA-10; R. Powers, HSA-10)