This paper presents an active replication scheme for the road-side units (RSUs) of an infrastructure-based vehicular network. This mechanism is part of a wider strategy that aims to enhance dependability and provide real-time guarantees in wireless vehicular communications. For that purpose, a fault-tolerant network architecture was proposed, which includes, besides the redundancy scheme presented in this paper, the design of fail-silent RSUs and medium guardians for the on-board units (OBUs) placed inside the vehicles. These strategies target the integration with the operation of a deterministic medium access control (MAC) protocol named Vehicular Flexible Time Triggered (V-FTT), in order to ensure the timeliness properties of this protocol. Nevertheless, the proposed mechanisms are protocol independent and can be employed in other wireless communications domains. The need for such mechanisms is explained in this paper, as well as the architecture, implementation and experimental validation of the proposed replication scheme.