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1 A vital aspect of cost-effective highway asset management is the estimation of asset life expectancies. With reliable estimates of asset life, agencies can, with greater confidence, establish schedules for rehabilitation and replacement; carry out planning, programming, and budgeting; and identify designs best suited to a specific situation or location. This report presents, for purposes of asset life expectancy estimation, a review of the various approaches and methods and a framework that can be implemented using empirical data. The frame- work includes identification of the influential factors of asset life expectancy and an assess- ment of the magnitude and direction of these factors. Further, the framework for assessing the sensitivity of asset life expectancy to maintenance is demonstrated. The framework can help agencies predict life expectancy corresponding to different levels of maintenance and preservation activities performed during the asset life or for the utilization of materials or designs that require very little or no maintenance. Also, recognizing that uncertainties surrounding asset life estimates can jeopardize the reliability of planning, the report de- velops and demonstrates a methodology for incorporating asset life uncertainty into long- term planning tasks such as capital needs assessments. Thus, the overall framework uses sensitivity and risk concepts to demonstrate how the uncertainties in asset life factors could affect the reliability of the estimated life and how, in turn, the uncertainty in the estimated life could affect planning outcomes. The report is accompanied by a Guidebook intended to facilitate the framework implementation by highway agencies. The Guidebook demon- strates how agencies may not only establish the life expectancies of their physical highway assets, but also investigate the sensitivity of these life expectancies to the relevant influential factors of asset life and assess the effects of asset life uncertainty on their asset management processes. S u m m a r y Estimating Life Expectancies of Highway Assets; Volume 2: Final Report
