The conventional approach to designing flexible pavements relies heavily on practical experience and simplified two-dimensional computer analysis. However, there is a growing trend in the transition towards more advanced mechanistic design methods, which aim to overcome the limitations associated with stress, strain, and displacement predictions in pavement analysis. This study examines the critical implications of departing from a circular contact area assumption in pavement design, as the Layered Elastic Theory proposed. Accurate tire-pavement interaction is essential to evaluate the pavement damage caused by various tire configurations. Actual tire measurements in this study revealed substantial deviations between the assumed circular contact area and actual contact areas for dual axle with reductions of 3.4% and three-axle trucks with reductions of 5.6%, leading to concentrated loads on smaller surface areas. This concentration results in elevated stress levels on the pavement surface, increasing the risk of damage and fatigue failure. The study revealed that. The study also identifies increased strain values, indicating a greater likelihood of rutting. Finite Element Analysis (FEA) using Abaqus FEA software was used to analyze the pavement responses. The study recommends considering actual contact areas, highlighting the importance of precision in engineering calculations and paving the way for more resilient and sustainable transportation infrastructure.