Unpaved roads constitutes a significant portion of road networks in developing countries. These roads are constructed by a succession of layers of unbound granular materials having different characteristics. From the geotechnical point of view, unpaved roads involve numerous complexities in their behavior such as: repetitive loads producing accumulation of plastic strains, stress rotation, abrasion and crushing; and all that occurs in unsaturated soils having strong interaction with the environmental conditions. The principles of current applied to unpaved roads are based on the results of the California Bearing Ratio tests (CBR). However this test is more related with the strength characteristics of the material (friction angle and apparent cohesion) than its stiffness (young modulus and Poisson ratio). This paper presents the influence of the intrinsic variability of soil parameters in the California Bearing Ratio tests by means of numerical simulations. These simulations were performed to penetrate a soil sample with a plunger of standard area using a random finite element method, in terms of soil parameters. The results of the CBR test are discussed.