Concrete safety barriers: conditions of utilisation

The theme of safety for the vehicles on the road is very important and involves problems of several kinds. A system to limit the damages produced by the road accidents consists in placing at the edges of the road fixed and continuous obstacles which are called "safety barriers". In Italy, technical and technological evolution has substantially caused the utilisation of two kinds of barriers only: metallic barriers with "w" section and concrete barriers derived from the New Jersey model. This study is born from the evidence of the present increased spreading of the concrete barriers: its objective is to try to characterize, through a rational research, the conditions of utilisation that assure the advantage of this system. After a short examination of the different kinds of concrete barriers the study continues with the question of the theoretical analysis of the contact phase between vehicle and barrier, drawing some interesting considerations. The next step is represented by a careful examination of the different possible cases, the valuation of costs and benefits of each, with the intent to obtain a table of the utilisations and in view of a necessary imminent norm.