Performance Evaluation Of The Guardrail To Concrete Barrier Transition Update To Nchrp 350 Test No 3 21 With 28 Cg Height 2214t 1 PDF Download

Two approach guardrail transitions for use with concrete safety shape barriers were developed and crash tested. For this study, the transition systems were attached to the New Jersey safety shape concrete barrier; however, it is believed that these transition systems could be easily adapted to the F-shape barrier with no need for further crash testing. Both transition designs were constructed with two nested thrie beam rails measuring 2.66-mm thick. The first transition design was supported by nine W150x13.5 steel posts measuring, 1,981-mm long, while the second transition design was supported by nine 152-mm x 203-mm wood posts measuring 2,134-mm long. For both systems, post spacings consisted on one at 292 mm, five at 476 mm, and three at 952 mm. A triangular-shape concrete curb was constructed below the thrie beam rail on each approach guardrail transition system. The two transition systems successfully met the Test Level 3 requirements specified in NCHRP Report 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features."