Crash test and MASH TL-3 evaluation of the TxDOT short radius guardrail.

PDFTech ReportFHWA/TX-15/0-6711-1Project 0-6711GuardrailsImpact testsHighway safetySimulationFinite element methodT intersectionsCurved railTexasTexas A&M Transportation InstituteAbu-Odeh, Akram Y.McCaskey, KatherineBligh, Roger P.Menges, Wanda L.Kuhn, Darrell L.Texas A&M Transportation InstituteUnited States. Federal Highway AdministrationTexas. Dept. of TransportationUS Transportation CollectionWhen a roadway intersects a highway with restrictive features such as a bridge rail and canal, itbecomes difficult to fit a guardrail with the proper length, transitions, and end treatment along the highway.Possible solutions include relocating the constraint blocking the placement of the guardrail, shortening thedesigned guardrail length, or designing a curved guardrail.Curved, or short radius, guardrails typically present the most viable solution for these areas.However, no previously designed short radius guardrails meet National Cooperative Highway ResearchProgram (NCHRP) Report 350 Test Level 3 (TL-3) guidelines. Now, the American Association of StateHighway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) hasupdated crash testing criteria. The new guidelines supersede NCHRP Report 350 and increased the size oftest vehicles and changed the test matrices to include more impact conditions. Therefore, meeting newimpact standards for short radius guardrails has become more challenging.TTI researchers investigated, modeled, and simulated an optimized short radius design under thisproject. Subsequently, TTI researchers crash tested this system successfully to MASH 3-33, 3-32, 3-31, and3-35 test conditions. This innovative design utilizes an energy dissipation component plus a cable anchor thatprovides tension capacity to the rail section on the primary roadway, though an anchor BCT post on thesecondary road portion of the system. These new innovative design details made the system very effective incapturing the vehicles in short distances while using readily available components