Abstract: A crash barrier including a post secured to a base at its lower end, the post having a front face to which one or more rails are secured, the post also having two side faces and a rear face. The rear face of the post is formed with a horizontally extending notch having upper and lower surfaces. When an impact load is transmitted to the front face of the post, the post is caused to distort in a region including the notch so that the upper and lower surfaces of the notch close towards one another prior to any fracture at or adjacent the front face of the post or at or adjacent its lower end.