Statistical methods for evaluating the effectiveness of treatment at black spots are important for two reasons. First, they allow the engineer to determine how successful his efforts have been, and hence to estimate the costs and benefits of different types of treatment applied to different types of site. Second, they enable the researcher to test new treatment measures objectively. However, the methods which are currently used both in research and in local authority practice are not very suitable as a basis for making decisions. Bayesian methods, on the other hand, are ideally suited to this type of work. In this paper, a Bayesian approach to evaluation is briefly outlined. Some further developments in the Bayesian model, including an analysis based on a bivariate negative binomial distribution are discussed, and suggestions made for future research. For the covering abstract of the conference see IRRD abstract no 264967.
Samenvatting