Device-to-device (D2D) communications provide a promising technique for the fifth-generation (5G) wireless networks. It has been considered to support intelligent vehicular communications, such as in LTE-Vehicle (LTE-V). Particularly, it is very challenging to manage simultaneous handover of a massive number of fast-moving devices on the cell edge. In this paper, we propose a joint handover approach that effectively exploits D2D multicast and D2D clusters to address the severe resource contention caused by the high density and high mobility of mobile devices. The handover decision takes into account the received signal strength (RSS) from each candidate base station (BS) and the moving speed toward each BS. The simulation results show that the proposed solution can significantly reduce the communication interruption probability and handover latency of mobile devices in high-density and high-speed scenarios.