This paper proposes a novel cluster-based VANET oriented evolving graph (CVoEG) model to improve the reliability of vehicular communications. The CVoEG model divides vehicles into an optimal number of clusters based on link reliability and selects cluster heads and members based on their Eigen-centrality scores. A reliable routing scheme called CEG-RAODV is also proposed to find the most reliable path from source to destination using the CVoEG model. Simulation results show the proposed scheme significantly outperforms existing schemes in terms of reliability, packet delivery ratio, end-to-end delay, and throughput.