Vehicle crashes into fixed objects cost the Australian community more than one billion dollars per annum. One way of reducing the above costs is to redirect errant vehicles away from a fixed road hazard using a safety crash barrier. Determining what form of barrier is placed into a road environment has to date been mainly based on cost and preceding construction history. This paper proposes a new method of designing roadside crash barriers. The method is based on simulating, via a computer model, vehicles crashing into a barrier system in the road environment being designed. Statistical data relating to the barrier's real world in-situ crash performance is then linked with the simulation results. The method should complement the present approach adopted by road authorities - that is, road safety audits and crash barrier test performance. Some examples presented in the paper illustrate how crashes can be simulated using a computer to determine impact loads, vehicle kinematics and injuries to vehicle occupants. A flow diagram shows how the injury data output from these crash simulations is coupled to real world crash frequencies and injury costs to obtain the likely harm a barrier system incurs on road users for a particular road environment. The barrier system that generates the smallest harm to society can then be chosen. (A)
Abstract