Evaulation and Review of the Western Australian Black Spot Program
The purpose of this paper was twofold. First, it compared the criteria used by the different authorities in Australia to fund black spot treatments in their jurisdictions. Second, it presented the results of an evaluation of the effectiveness and cost-effectiveness of the Black Spot Program in WA. The findings presented in the paper form part of a wider review of the Black Spot Program in WA, which includes also a review of international black spot programs and a qualitative study of the views of stakeholders of the WA State Black Spot Program. The paper reports that different black spot programs within Australia have different eligibility criteria for funding and distribute varied proportions of funding to projects located on metropolitan, non-metropolitan, state and local roads. The WA Black Spot Program was found to be effective and cost-effective, with an overall crash reduction of 20% pre- and post-treatment and a BCR of 4.0. Factors that might have affected the evaluation of the effectiveness of the program were the lack of control sites and no account being taken of crash migration. It is difficult to identify what the best criteria for funding are in order to achieve an optimal reduction in crashes, with different stakeholders disagreeing on how funding should be distributed across road types and between metropolitan and non- metropolitan regions. A recent international investigation on state-of-the-art black spot approaches suggested an alternative approach, the empirical Bayesian method, as best practice for identifying black spots. Empirical Bayesian methods, however, require comprehensive and connected crash, road and traffic data and may be currently unrealistic for Australian black spot programs. It also stated that reactive crash analysis was still considered the best indicator of black spots rather than proactive methods based on road safety audits. However, proactive identification of black spots through road safety audits is still likely to be highly relevant to several Australian states due to their large area and long stretches of remote roads where crashes are more dispersed.