Highway barriers are erected to delineate the roadway limits and serve as a warning that abnormal hazards exist outside those limits. The barriers are also intended to physically restrain vehicles from entering areas they cannot safely traverse. Obviously, a successful barrier must prevent a vehicle from passing through of over it. However, equally as important, impact with the barrier should not overturn the vehicle nor result in decelerations that would preclude human survival. In addition, the vehicle should be redirected so as not to become a hazard to adjacent or following traffic. Several agencies have investigated the protection offered by existing barrier systems and the capabilities of new designs. The majority of such studies have involved either static or dynamic testing of barrier components, model barrier tests or full-scale tests. The purpose of this investigation was to review the existing information, developed a rational method of evaluating barrier performance and verify the predicted vehicle reaction with full-scale tests. With this goal in mind the state of New York, Department of public Works in cooperation with the U.S. Department of commerce, Bureau of public Roads sponsored a combined analyses and testing program at Cornell Aeronautical Laboratory, Incorporated of Buffalo, New York. During this study mathematical models were developed to describe the relationship between applied horizontal load and the resulting lateral deflection for three general classes of highway barriers. Vehicle trajectory, during impact with a barrier, was the predicted by a forth mathematical model. Input to the vehicle trajectory model consisted of the vehicle characteristics, speed, angle of impact, and barrier characteristics as described by the appropriate load-deflection model.Due to the complexity of the mathematical models they were programmed for solution on electronic data processing equipment. Sevenfull-scale crash tests were performed on five barriers to verify the mathematical predictions.
Abstract