Fifth-generation mobile communication technology (5G) has greatly promoted the development of vehicular communication. Millimeter wave (mmWave) technology is becoming the magic key to enabling the high data rate exchange of future onboard devices. Due to the severe path loss at mmWave, the cell radius is short and causes frequent handovers for vehicle user equipment in the mobile network environment. The above problems increase the risk of communication interruptions and pose threats to driving safety. Thus, it is critical to understand the channel characteristics during handover and find a suitable handover mechanism for future vehicular communications. In this work, vehicle-to-infrastructure (V2I) measurement campaigns are first conducted in urban scenarios using the moving network (MN) system. The measurements confirmed the potential benefits of beam-switching during movement and calibrated the ray-tracing (RT) simulator. Then intensive simulations are carried out for the handover procedure in the urban scenario. Based on simulation results, channel parameters are extracted and the channel characteristics for the handover procedure are studied. Finally, it is proposed to use beam-switching to complete the handover by evaluating handover parameters in detail. Compared to the conventional single beam, the beam-switching mechanism improves the SINR by about 30%, significantly enhancing the link quality during handover in the MN system.