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Determining Life Expectancy of Preventive Maintenance Fixes for Asphalt-Surfaced Pavements

A large performance data set from in-service pavements was used in conducting a reliability-based analysis to determine the life expectancy (performance) of several preventive maintenance (PM) fixes. The distress index (DI)—the main pavement performance indicator used by the Michigan Department of Transportation—was used in the analysis. Probability distributions of DI values were developed at successive years after the PM application for five fixes: nonstructural bituminous overlay, surface milling with a nonstructural bituminous overlay, single chip seal, multiple-course microsurfacing, and bituminous crack seal. Reliability tables were then developed to express the probability that a given PM treatment would reach the performance threshold after n years; these tables therefore provide the pavement life expectancy for a given PM treatment at various reliability levels. A highway agency can use these tables to select PM strategies on the basis of expected life extensions.