Determination of a Dedicated Concrete Pavement Network Using Probabilistic Life-Cycle Cost Analysis

In 2001, the Québec Ministry of Transportation (MTQ), in Canada, adopted a policy subdividing the existing pavement network into dedicated concrete and asphalt networks. This paper presents the methodology used for determining these respective dedicated networks using probabilistic Life Cycle Cost Analysis (LCCA). Sixteen (16) different combinations of Average Annual Daily Traffic (AADT), number of lanes, truck percentage, and truck factor yielded 32 pavement designs in asphalt and concrete that were compared in pairs over an analysis period of 50 years using a probabilistic LCCA software. LCCA results from these standard cases were then analyzed to find regression equations correlating the Net Present Value (NPV) of each alternative (average and standard deviation) to the most significant parameters. The network allocation criteria were determined by applying dominance tests to these probabilistic results; in the areas without clear dominance further analyses would be necessary using project-specific data. Work zone user costs were first computed but they were not taken into account because of their “softer” nature and their larger inherent uncertainty compared to construction and rehabilitation costs, but mostly because it was found that the lack of a remaining serviceable life value for these costs caused problems that cast doubt on the results. The final selection criteria were applied to the Province’s pavement network and the result was mapped. After minor adjustments to ensure continuity as much as possible, the respective networks (“white” for concrete, “black” for asphalt and “gray” for further analysis) were established officially. The policy making this network allocation official is scheduled for review every 5 years.