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November 1, 2004
Refer to: HSA-10/B-129
Mr. Anthony J. Carey
President
Barriers USA, Incorporated
5850 Sawmill Road
Paradise, California 95969
Dear Mr. Carey:
In September, you sent Mr. Richard Powers of my staff copies of an August 2004 test report prepared by Dr. Roger Zou and Professor Raphael Grzebieta in the Department of Civil Engineering at Monash University in Victoria, Australia. This report detailed the results of two National Cooperative Highway Research Program (NCHRP) Report 350 crash tests into a water-filled plastic barrier/W-beam rail design called the Guardliner System and you requested formal acceptance of its use in the United States. Mr. Powers has reviewed the report as well as additional information on the Monash University crash test facility that was subsequently provided by Professor Grzbieta and has concluded that the tests were conducted in conformance with the NCHRP Report 350 test and evaluation procedures and can be accepted as such.
The Guardliner Barrier is comprised of polyethylene segments 2000-mm long x 960-mm high. Each is 600-mm wide at the base and 530-mm wide across the top, weighing approximately 50 kg when empty and 630 kg when filled with water. Units are connected at each end by 30-mm diameter steel bolts 200-mm long. A W-beam guardrail complying with the American Associaton of State Highway and Transportation Officials' M 180 specification for steel beam guardrail is attached to the traffic face using special steel linkage brackets. Enclosure 1 is a schematic drawing of the Guardliner design.
To certify this barrier as meeting the NCHRP Report 350 test level 2 (TL-2) evaluation criteria, test 2-10 and 2-11 were conducted. Enclosure 2 contains the summary test sheets for each test. The maximum reported deflection for test 2-11 was 2640 mm and occurred when the pickup truck impacted near the joint between segments 12 and 13. The test installation was comprised of 30 units and the ends were free-standing. As with all unanchored barrier installations, impacts nearer either end would have resulted in greater deflections. Impacts very near the ends may not have contained or redirected the vehicles. Since there is currently no crashworthy terminal for the Guardliner, its ends should be flared away from approaching traffic or adequately shielded. Based on the performance of the Guardliner, it may be considered an NCHRP Report 350 TL-2 temporary traffic barrier and used at appropriate locations on National Highway System (NHS) when selected by the contracting authority.
Please note the following standard provisions that apply to FHWA letters of acceptance:
Sincerely yours,
(Original Signed By R. Powers)
for:
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety