This report provides a summary of the findings of two evaluations, with different methodologies, to determine the impact of a random breath testing (RBT) initiative in Victoria on severe crashes in high alcohol times of the week during 1990 and 1991. Bus-based RBT stations largely replaced car-based stations and a publicity campaign through all mass media was lanched. It was found that the initiative reduced fatal high alcohol hour crashes in Melbourne during 1990. Serious high alcohol hour casualty crashes in the rural areas around Melbourne were reduced. It was also estimated that there was a reduction in serious high alcohol hour casualty crashes in rural Victoria. The effect on Melbourne serious high alcohol hour casualty crashes was harder to estimate. The choice of the appropriate model to represent the expected post-intervention trends, and hence estimated change, differed between the two studies. The first study, using an estimate which emphasised the new road safety trend prior to the intervention, found no statistically significant evidence that the RBT program had an effect. In contrast, the second study, using a model which basically place equal weight on the trend for the twelve month pre-intervention period, suggested that RBT reduced crashes. (A)
Abstract