Evaluating the Cost Effectiveness of Flexible Rehabilitation Treatments Using Different Performance Criteria

Abstract

At a certain point in the life of a flexible pavement, rehabilitation is required to improve pavement condition and to defer reconstruction. Pavement managers seek the best rehabilitation treatment on the basis of cost effectiveness. Using 1994–2002 data from a wet-freeze mid-Western state in the United States, this paper analyzes the cost effectiveness of four flexible pavement rehabilitation treatments: functional hot-mix asphalt (HMA) overlay, structural HMA overlay, resurfacing (partial 3R standards), and mill full-depth and asphaltic concrete overlay. The performance indicator used is the international roughness index and treatment effectiveness is measured in terms of performance jump (short-term), and service life and increase in pavement performance (long-term). The treatment cost is the equivalent uniform annual cost per lane-km incurred by the agency and user; and cost effectiveness is the ratio of effectiveness to cost. The study estimated treatment effectiveness under various combinations of traffic loading and climatic condition, and initial pavement condition. The results suggest that in the short-term, HMA structural overlay is the most effective treatment. For the long-term, the results are equivocal: HMA structural overlay is most effective from the perspective of average performance over the treatment life; resurfacing (partial 3R standards) is the most effective from the perspective of treatment service life. With regard to cost effectiveness, however, the results were consistent: for all three measures of treatment effectiveness, mill full-depth and asphaltic concrete overlay unequivocally appears to be the most cost effective treatment. Finally, the paper recommends that cost effectiveness analysis should be accompanied by a candid deliberation of project constraints, the local environment, and agency practices.