Vehicle routing problem (VRP) is a hard combinatorial problem. In practice, specificities of concepts (vehicles and networks transportation) related to VRP must be explicitly considered in modeling to obtain accurate cost and feasible solutions. Each of these concepts is represented in literature for a specific purpose. In this study, we present an ontology for modeling VRP as a unified representation based on road and vehicle classification. The approach proposed aims at providing decision-makers in transport companies a consistent understanding of the field based on ontology. Moreover, it aims at generating parameters of classification of VRPs, and at facilitating later on solving these problems, in the academic or industrial context.