Probabilistic vs. Deterministic LCCA for Perpetual Pavements

The Lifecycle Cost Analysis (LCCA) is an essential tool highway officials use to evaluate the merits of different pavement design alternatives and make suitable transportation investment decisions. However, the LCCA uses inputs that are inevitably highly uncertain. The deterministic LCCA approach is easy, uses average input values, and is straightforward to determine the low-cost pavement alternative. However, it cannot consider the uncertainty of inputs and can result in ill-informed investment decisions. Further, deterministic LCCA for perpetual pavements designed to serve 50+ years makes the decision-making challenging. The LCCA results presented in this paper illustrate the advantages of the probabilistic approach. Considering the uncertainties in the LCCA inputs due to data shortages or estimation errors, using probabilistic LCCA in pavement design is vital, especially for alternative comparisons involving perpetual pavements. The ability of the probabilistic approach to enable the user to choose the desired level of risk in decision-making and the scarcity of data for the perpetual pavements makes the use of probabilistic LCCA more attractive. In addition, the ability of probabilistic analysis to investigate what-if scenarios can determine suitable and optimum situations where perpetual pavement construction would result in cost savings.