South Australias New Concrete Median Barrier (Mar 1981)

Safety on the public road is a matter of concern to the whole community. Fast moving opposing streams of traffic are often separated only by air and paint and the potential for collisions is high. Many campaigns are conducted to improve driver education and performance; regulations require an increasing number of built-in safety devices within vehicles. There is also considerable scope for building safety into the road itself. Throughout Australia concrete safety barriers are being used to improve the safety of both new and existing roads. When used as median barriers, their most common role, they minimise the risk of head-on collisions which represent a high proportion of accidents. The rigid concrete barrier does not deflect under impact, its profile is such that at the normal angle of impact a vehicle is redirected back into the adjacent traffic lane. The impact energy of low angle collisions is principally dissipated by the compression of the vehicle’s suspension system. The vehicle is redirected by its wheels, not its body, with little or no damage to the vehicle and seldom more than tyre marks on the barrier. Even on the rare occasions when a vehicle hits a barrier at a greater impact angle, there is little likelihood of the vehicle breaking through; some vehicle damage may, however, occur.