LINEAR SHRINKAGE IN TRAFFIC ACCIDENTS MODELS

In traffic accident models for estimating the expected number of accidents at a road junction, the estimate is obtained as a weighted average of the observed number of accidents at the junction and some normal value. This normal value can be the mean value for a group of similar junctions or anotherwise predicted value. The estimate of the expected number of accidents can be regarded as a linear shrinkage of the observed value towards the normal value. In this study, general formulas for the shrinkage parameter are given. The formulas are obtained by applying the method of least squares to linear models. (A)