Incorporating User Costs into Pavement Management Decisions

Despite clearly established federal guidelines, few State Department of Transportation's (DOT’s) include user costs, other than pavement works related travel delays, in pavement life cycle cost analysis (LCCA). Omitting the variety of other user cost components, particularly those related to vehicle operating costs, can potentially skew the results. The international literature abounds in studies that relate user cost components (e.g., fuel consumption, repair/maintenance and so on) to pavement roughness. Recent evidence has shown that pavement roughness has a significant effect on certain user cost components of trucks and passenger cars for the conditions encountered in European and US conditions. This paper demonstrates how these user cost relationships, along with agency costs, can be incorporated into the process of making pavement investment decisions at both the network and project levels. The process is implemented into a software package named Pavement Investment Decisions (PID). This software is generic and specially designed to be adaptable to the practices of various State DOT’s. At the network level, sections are flagged in order of decreasing ratio of user benefit divided by agency cost. User benefit is calculated as the reduction in user costs from its current roughness to the roughness of a new pavement. The agency cost is considered to be that that corresponds to the most capital intensive pavement 4-R treatment. At the project level, the available budget is allocated amongst the sections identified in a away that maximizes the user benefits over the analysis period. The pavement management database of the Washington State DOT was used to implement this methodology and pilot test PID.