Geosynthetics have been used commonly in the past three decades to stabilize and to improve the service life of pavements. Various researchers have conducted large-scale model studies, accelerated pavement testing, and numerical model simulations to evaluate the benefits of reinforcement in pavements. Conventional method for design of pavements is based on layered elastic theory and ensuring that the stresses under wheel load are within allowable stresses of each pavement layer. In order to model the critical response of pavement accurately, it is essential to consider the non-linear behavior of pavement. This study focuses on three-dimensional numerical modeling of unreinforced and reinforced flexible pavements using explicit finite difference program – FLAC3D. This study also uses various constitutive models to evaluate the mechanistic behavior of pavement section. The improvement in reinforcing base layer is presented in terms of load-settlement curves and the maximum settlements at the surface are presented. This research is relevant at places where reinforcing the aggregate base layers is essential to improve the performance of pavement system and to reduce the quantity of aggregate material needed for their construction.