Evaluation of Existing T-Intersection Guardrail Systems for Equivalency with NCHRP Report 350 TL-2 Test Conditions (405160-10)

When a road or driveway intersects a highway with certain restrictive features (bridge rail, culvert...etc), it is difficult to fit the proper guardrail length (transition, length-of-need guardrail, and end treatment) along the primary roadway. Site constraints such as private driveways, state roads, and parish or county roads may intersect the primary road and not allow the placement of a properly designed guardrail length of need. In these cases, alternatives are to shorten the designed guardrail length, provide a curved or T-intersection guardrail design, or relocate the constraint blocking placement of the guardrail. This curved guardrail system is usually known as a short radius guardrail. This study investigated the performance of previously tested short radius systems to determine if some of the previously tested short radius guardrail systems meet NCHRP Report 350 TL-2 evaluation criteria. A system designed and tested for Yuma County, Arizona was used as the basis for developing a short radius guardrail system that satisfies NCHRP Report 350 TL-2.