An accident information system as aid to safer roads

Fundamental to any consideration for improvements to a road system or its traffic operations is the establishment of a data base giving details of road traffic accidents, their numbers, causes, types and locations. The Highways Department of South Australia is responsible for processing accident data contained on police accident report forms for its own purposes as well as for other authorities that need accident information. Details of the types of data collected, the methods used for location coding and editing data for computer processing, and the filing of accident report forms are given. Methods for identifying hazardous locations involve accident numbers given by spot maps, types and severity of accidents shown by collision diagrams and tabulations, and accident rates with tests for statistical significance for road sections. The determination and use of an accident severity index for road sections and an accident cost rate for intersections is described. (A)