The report identifies aggregations of crashes by location (black spot), or by other common characteristics. Further work involved correlating crash occurrence with road parameters such as alignment, roughness etc, on a selected sample of road and the feasibility of automating the procedures nationwide was examined. It was concluded that (I) roughness and road width did not appear to have any effect upon crash frequency; and (II) horizontal alignment and road grade appeared to have an effect upon crash frequency, in so far as certain road sections experience higher than average crash frequencies. These road sections are those for which some proportion of the horizontal alignment is curved or consists of grades greater than 2 per cent. Attempts to further quantify the relationship between crash frequency and road environment proved inconclusive.
Samenvatting