Comparisons of accident frequencies are often done with a view to identifying how individual countries are performing relative to others in road safety experience. While such comparisons can be quite useful from a public health management perspective, they can be misleading to those who want a sense of how specific road safety initiatives are performing compared to similar ones in other countries. In particular, these comparisons will not allow engineers in one country to assess how well their designs for individual roadway elements are performing relative to the experience in other countries, or to the earlier experience in the same country. This paper has been prepared with three fundamental objectives in mind. Comparisons of selected accident prediction models (APMs) from New Zealand, North America, Sweden and Australia are made to (1) illustrate how such comparisons might be used to learn lessons from differences in crash experience for similar roadway elements; (2) investigate and discuss the factors that could account for differences in accident experience observed from the model comparisons; and (3) illustrate how to assess the transferability of these models among countries. The results suggest that it does appear possible to transfer models from one country to the next, but there are a number of differences between countries that need to be accounted for. (A). For the covering abstract of the conference see E216632.
Abstract