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Evaluation of Long-Lasting Perpetual Asphalt Pavement with Life-Cycle Cost Analysis

In 2006, the Oklahoma Department of Transportation sponsored work at the pavement test track of the National Center for Asphalt Technology to compare the performance of two sections that had been designed to determine the necessary thickness for perpetual pavement. One section (Section N9) was designed to be a perpetual pavement at 14 in. thick. The other section (Section N8), at 10 in. thick (according to the AASHTO 1993 design guide), was used to test performance and to identify the thickness needed for perpetual pavement. This paper presents a life-cycle cost analysis for quantifying the benefits of a perpetual pavement section compared with the long-term cost of the thinner section. The life-cycle cost analysis was conducted with RealCost 2.5, which was available through FHWA, and included a determination of quantitative estimates of construction schedule, work zone user costs, and agency costs for initial construction and rehabilitation activities. The perpetual pavement section was found to have had a lower life-cycle cost than the conventional pavement section and to have provided better service to highway users. For better planning of future preservation studies, the estimated present serviceability rating as a function of the international roughness index for two designs (perpetual and nonperpetual) was evaluated. The findings of surface measurements for both sections demonstrate a clear difference between perpetual and conventional pavement serviceability for a given level of roughness and accumulated traffic. These results are also useful for assessing the improvement of conventional pavement after rehabilitation treatments.