Two crash tests each were performed on a Thrie beam bridge rail and on the adjoining transition section to the approach guardrail. The bridge rail was designed (a) as a retrofit to replace the rail portion of an inadequate bridge rail supported on w6x15.5 Steel posts at 6 ft 3-in. Spacing, or (b) as a completely new barrier installed using resin capsule anchors to attach the posts to the edge of an existing bridge deck. The transition uses the same rail element, a 10-gauge Thrie beam, supported on standard wood posts. The tests performed approximated those required for a pl-1 bridge rail outlined in the 1989 American Association of State Highway and Transportation Officials' "Guide Specifications for Bridge Railings". The bridge rail was struck by a 5, 400-lb pickup truck at 44.9 Mph at an angle of 21 deg and a 1, 830-lb car at 48.7 Mph at an angle of 18 1/4 deg. The transition was hit by a 5, 400-lb pickup truck at a speed of 44.7 Mph at an angle of 18 deg and a 1, 930-lb car at 49.1 Mph at an angle of 20 3/4 deg. The crash tests satisfied the requirements for structural adequacy, occupant risk, and vehicle trajectory in national co-operative highway research program report 230 as well as the evaluation criteria in the American Association of State Highway and Transportation Officials' guide specification.
Samenvatting