Some implications from the in-depth study and simulation modelling of road departure crashes on bends on rural roads

Abstract

Previous work by the authors has questioned the philosophy of reliance on clearzones, rather than barriers, for rural road safety. In-depth investigation and simulation modelling of a sample of real world crashes has highlighted that even if clearzones of 10 metres could be achieved throughout the rural road network, there are certain vehicle control mechanisms that are not adequately accommodated when a vehicle departs the road. This paper extends this work based on 64 investigated crashes on rural roads at bends and nine computer simulations of these crashes. Bends are over-represented in rural crashes yet the provision of clearzones tends to mimic that of straight sections of road in practice. The study summarizes the characteristics of the investigated crashes in the context of departures and vehicle control mechanisms and discusses the implications of the findings on the provision of safety features on rural roads. The provision of roadside barriers is also discussed including location relative to the bend and offset from the edge of the traffic lane.