Federal Highway Administration
400 Seventh St., S.W.
Washington, D.C. 20590
November 30, 2005
In Reply Refer To:HSA-10/B-81A
Mr. M.G. Patel, P.E.
Chief Engineer for Highway Administration
Pennsylvania Department of Transportation
P.O. Box 2951
Harrisburg, Pennsylvania 17105-2951
Dear Mr. Patel:
In your November 7, 2005, letter to Mr. Rudolph M. Umbs, you requested a test level 4 (TL-4) acceptance of two W-beam transitions to a concrete bridge rail. These same two designs were previously accepted as TL-3 transitions in Mr. Frederick G. Wright's June 26, 2001, letter to Mr. Michael M. Ryan, which was designated as the Federal Highway Administration acceptance letter B81.
To support your current request, you included a copy of an October 2005 test report prepared by the Texas Transportation Institute entitled "NCHRP Report 350 Test 4-22 of the PennDot Standard BC-739M Bridge Barrier to Guide Rail Transition (BC-739M)" and a videotape of the crash test that was successfully conducted with an 18,000-lb single-unit truck. Staff members have reviewed the test results and the videotape and agree that all the National Cooperative Highway Research Program Report 350 evaluation criteria were met. Accordingly, the two designs identified in acceptance letter B81 may now be considered TL-4 designs and used as such on the National Highway System.
/original signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety
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