This paper examines, the relationship between the frequency of single vehicle roadside accidents and the lateral placement of the most common roadside hazards and shows how this relationship could be used as a basis for the development of a roadside safety improvement programme. Data were collected from 195 sites in the Tyne and Wear area, in order to identify objects involved in collisions and measure their lateral distance from the edge of the pavement. The roadside hazard concept and system safety technology are then combined in a unified methodology to the quantitative evaluation of roadside safety. All relevant roadside safety knowledge has been encapsulated in a computer system called ROSDIS ROadside Safety called ROSDIS ROadside Safety Design and Improvement System. This system enables the user to experiment with different configurations of fixed roadside objects and select the configuration which minimises the probability of collision using fault tree analysis. The structure of the fault tree allows the incorporation of other factors such as the severity associated with each roadside hazards. Costs for different alternatives can also be included to determine the most economical one. It is intended to extend the system in the future using severity and cost.
Samenvatting