This paper presents the results of an evaluation of 51 'Black Spot' projects funded by the Australian Government. The evaluation was based on the record of accidents before and after approved treatments. In order to isolate treatment effects, adjustments were made to take account of the recent decline in accidents. A major part of the analysis compares how accident severity and type methodologies differ in assessing the effectiveness of the three most common treatments: installation of new traffic lights; modification of existing traffic lights (mainly installation of separate right-turn phases), and construction of roundabouts. The evaluation took the form of a benefit cost analysis. Various measures of effectiveness are presented for assumed project lifetimes of 20 and 10 years using a primary discount rate of 7 per cent. Except where a fatality occurred in the 'before' period, the accident-type approach produced much higher benefit cost ratio estimates. A number of matters are identified for examination in the full evaluation which will follow. For these reasons and because of various sample characteristics discussed in the paper, caution needs to be exercised in generalising the results of the pilot study. Nevertheless, the results suggest that the Black Spot Program has yielded substantial benefits to road users. (A).
Abstract