Recently, vehicle-to-vehicle (V2V) communications for future cellular systems have attracted considerable attention due to their potential benefits such as improved system capacity, spectral efficiency or delay reduction, and they enable new services related to intelligent transportation systems. V2V communications can be performed using two communication modes, namely cellular mode, based on uplink/downlink communications, and sidelink mode, which enables vehicles to communicate directly with other vehicles. However, selecting the appropriate operating mode according to the requirements of V2V services and allocating the radio resources to V2V communications becomes a challenging issue. In this respect, we propose a novel mode selection and resource reuse strategy to select the appropriate mode of operation and decide the amount of resource blocks (RBs) for V2V in cellular and sidelink modes, where multiple V2V links may share the same radio resources. A simulation-based analysis is presented to assess the performance of the proposed solution. The simulation results have shown that the proposed strategy improves network performance in terms of achievable throughput, outage probability, latency, and resource utilization.