The current study aims at developing well-predicting regression equations for evaluating the fatigue and rutting strains at critical locations within the flexible pavement layers. With an objective to develop unified regression models, the practical on-field ranges for thickness and layer moduli of various pavement layers are used in the analysis. These design input combinations are fed into a multilayer elastic analysis program using an automation technique to reduce a lot of human effort and evaluation time. The output obtained from the program is used to develop equations for fatigue and rutting strains by nonlinear regression analysis. The outcomes of this study will aid the design engineers as well as researchers in multiple ways. In addition to the advantages in pavement design, the automation procedure combined with regression would also aid the researchers in simulation studies, reliability analysis, etc. © 2019, Springer Nature Singapore Pte Ltd.