The collision of the heavy goods vehicle against the road safety barriers on horizontal curves

Although run off the road accidents frequently occur on horizontal curves the performances of the safety barriers are evaluated by full scale crash tests which are performed on rectilinear safety barriers and no one study aimed at evaluating the safety barriers behavior on curves has been done. In this paper the results of a study aimed at evaluating the dynamics and the outcomes of the collision of the Heavy Goods Vehicles against the road safety barriers on horizontal curves are reported. The study has been carried out by a numerical approach, which involves simulating collisions with safety barriers through non-linear dynamic finite element analysis. The study has highlighted the factors responsible of the different behavior of the safety barriers on the horizontal curves: the change in the restraint system stiffness and the different yaw motion and vehicle’s velocity change needed to redirect the vehicle in carriageway. The previous factors strongly affect the barrier containment capacity. As far as the maximum transversal barrier displacement is concerned it decreases on the outside of the curves whereas it increases on the inside. The greater barrier displacement on the inside of the curves causes an increase in the passing over the barrier risk. As far as the vehicle roll over risk is concerned it strongly increases on the outside of the curves, where the run off the road accidents are significantly greater.