Research has developed railings to withstand impact loads from vehicles of ever-increasing size; however, aesthetic considerations have been overshadowed by safety and structural requirements. The objective of this research study was to develop aesthetically pleasing, structurally sound railings that can serve as alternative railings in city or urban areas. A new steel pipe bridge rail--texas type t421--is introduced. This bridge rail is constructed of 5-in.-Diameter steel pipe posts with a 5-in.-Diameter steel pipe top rail 32 in. High and a 10-in.-Diameter steel pipe lower rail. The bridge rail was crash-tested and evaluated in accordance with nchrp report 230. Two crash tests were required--a 4, 500-lb passenger car at 60 mph and 25-deg impact angle and an 1, 800-lb passenger car at 60 mph and 20-degimpact angle. In both tests the bridge rail contained and redirected the test vehicle. There were no detached elements or debris to present undue hazard to other traffic. The vehicle remained upright andrelatively stable during the collision. The occupant-compartment impact velocities and 10-msec occupant ridedown accelerations were within the normally accepted limits. The vehicle trajectory at loss of contact (exit angles of 5 and 7.6 Deg) indicated no intrusion into adjacent traffic lanes. This paper appears in transportation researchrecord no. 1319, Bridge and hydrology research 1991.
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