ABSTRACT
International Roughness Index (IRI) is a widely accepted measure for pavement smoothness and is considered as one of the most important factors affecting the functional performance of pavement structures. As such, may researchers in the past have developed empirical IRI models to forecast future IRI as well as the remaining life of existing pavements. In this paper, a methodology for mechanistic-empirical IRI prediction is introduced. The methodology utilizes the pavement structure and the initial surface profile (rather than initial IRI) to predict the spatially varying dynamic load and rut depth values. The nonhomogeneous rut depth is then used to update the pavement surface profile from which the IRI is evaluated again. Following the description of the methodology, the paper provides a simple example comparing the mechanistic-empirical IRI results against those from an empirical model.
