In this paper, we investigate network performance for vehicle-to-everything (V2X) communications in 5G vehicular networks. The V2X communications enable various services included in the latest standard released by the Third Generation Partnership Project (3GPP). In V2X communications, resource allocation plays a crucial role to exchange information between vehicles and other equipment. To evaluate its influence on network performance, we firstly develop a network model for V2X communications in urban areas, and then various services are considered in the model. Simulation results reveal that the dynamic resource allocation specified in the current standard, while able to avoid transmission collisions, cannot provide guaranteed services needed by intelligent transportation systems (ITS), especially for the enhanced V2X services in urban areas. Consequently, a location-aware resource allocation (LARA) strategy is proposed to tackle the discovered issues. Compared with its standard counterpart, the proposed approach can effectively improve the resource utilization and boost the network performance.