In real field scenario, most of the unpaved roads in rural area rest on locally available deformable soil subgrade having generalized shear strength parameters. During the construction and vehicular loading stages, the weak subgrade undergoes deformation, thereby necessitating proper ground improvement to increase the strength of the deformable subgrade. The already established analytical formulations fail to illustrate the effect of individual deformation in the subgrade and aggregate layers. Owing to this, for such cases, finite element (FE) studies become imperative to understand the response of an unpaved road structure. This paper presents a FE based design approach of unpaved road system comprising a weak soil subgrade supporting an aggregate layer that is subjected to quasi-static vehicular load. The design is based on stress-deformation approach, wherein failure of individual layers of unpaved road structure is considered. Subsequently, upon noticing failure, the subgrade strength is suitably altered such that the unpaved road system remains safe from both deformation and stress-based failures. Alternatively, the efficacy of incorporation of geosynthetic reinforcement at the interface of aggregate-subgrade is illustrated through FE analyses conducted on the initially considered unpaved road system resting on weak subgrade. Furthermore, the benefit of using a geosynthetic layer of specific tensile strength in the reduction of aggregate thickness is also elucidated. Thus, this study successfully portrays the dual advantage of applying geosynthetic in unpaved road system, i.e., enhancement in load sustenance and reduction of aggregate thickness.