The Intelligent Transportation System protocol stack (ITS-G5/802.11p) has revolutionized traffic efficiency and road safety applications in vehicular environments. This study presents a novel architecture for communications, utilizing IPv4 multicast over 802.11p/ETSI ITS-G5, which addresses the challenges of a specific urban use case involving a Level Crossing (LC) in Bordeaux. Our proposed architecture focuses on the broadcast of Cooperative Awareness Message (CAM) and Decentralized Environmental Notification Message (DENM) to enhance road user safety. To prevent accidents, an algorithm for CAM and DENM dissemination has been devised, ensuring timely alerts for sudden vehicle blockage emergencies. Moreover, a comprehensive and optimized train braking strategy is introduced to further minimize accident risks. This strategy aims to provide efficient and timely train deceleration, allowing sufficient time for road users to clear the level crossing and mitigating the potential for collisions. To evaluate the system's performance, we analyze key metrics, including End-to-End (E2E) delay and Packet Reception Ratio (PRR). Furthermore, our work includes a comparative analysis between our proposed edge-server-based architecture and a cloud-based architecture. This analysis provides valuable insights into the strengths and weaknesses of each approach. Through comprehensive experimentation and evaluation, our proposed approach demonstrates its efficiency and effectiveness in mitigating accidents and enhancing road safety. By leveraging the capabilities of ITS-G5, our research contributes to the advancement of communication systems for intelligent transportation. The findings of this study provide a foundation for future deployments and improvements in urban environments, fostering safer and more reliable transportation systems.