COMPUTER MODEL FOR LIFE-CYCLE COST ANALYSIS OF ROADWAY PAVEMENTS

This paper describes the development of a computer model that performs life-cycle cost analysis (LCCA) of roadway pavements, analyzing the cost of both the agency and the user. Agency costs are a function of the type of rehabilitation, restoration, resurfacing, or reconstruction (i.e., 4R) treatment applicable to each pavement type, given its surface distress and structural condition. The cost of each treatment is calculated from the unit prices specified for the activities involved and the roadway geometry. User costs include vehicle operating and nonvehicle operating costs, which are a function of pavement roughness, as well as user delay costs, which are a function of lane closure practice. User benefits are calculated as savings in user costs due to reduction in pavement roughness from its current state to that of a new pavement. At the roadway network level, sections are flagged for analysis in decreasing benefit-cost order, whereby the cost of the most capital-intensive 4R treatment is considered. Sections flagged at the network level are carried forward to the project level analysis. The project level analysis allocates the available budget among the sections selected to maximize user benefits over the analysis period. The software package implementing this methodology, called pavement investment decisions (PID), is generic; that is, it allows customizing through a series of input screens to fit the pavement management database and practices of any state Department of Transportation (DOT).