A Review of the Alabama Department of Transportation’s Policies and Procedures for Life-Cycle Cost Analysis for Pavement Type Selection

Abstract

This thesis examines the process of life-cycle cost analysis for pavement type selection and gives specific consideration to the policies and procedures used by the Alabama Department of Transportation as of June 2013. Life-cycle cost analysis is a structured approach to determine the economic benefit of an investment alternative over a lengthy time horizon. Life-cycle cost analysis is a common tool used to determine which pavement surface type, asphalt or concrete, should be used to best allocate transportation agencies limited resources. In order to accurately calculate the life-cycle cost of a pavement, the costs and timing of construction, maintenance, and rehabilitation activities must be known. Data collected from federal and nearby state agencies was used to best determine these parameters for use in Alabama. Other paramount factors, such as the analysis period and discount rate, were examined and recommendations were made based upon state-of-practice policies and sensitivity analysis. Five projects recently constructed in Alabama were examined based upon these recommendations. The recommendations were originally made by the National Center for Asphalt Technology to the Alabama Department of Transportation; these include an analysis period of 35 years, a discount rate equivalent to the rolling 10-year average of the OMB’s 30-year discount rates, a performance period of 19 years for new asphalt pavements and a rehabilitation period of 13.5 years for asphalt overlays.