CI-VAP V2X communication architecture integrates four layers—cloud, edge, vehicle, and pedestrian—to enable real-time cooperative awareness and safety messaging across connected and autonomous vehicles. The Cloud Layer hosts a Traffic Management Centre (TMC) with HD Maps and OTA Updates, while the Edge Layer deploys Roadside Units (RSU-1, RSU-2) using DSRC and C-V2X protocols, connected via a Network Gateway. Vehicle Layer implements V2V communication between Vehicle A (DSRC), Vehicle B (C-V2X), and Vehicle C (C-V2X), broadcasting Basic Safety Messages (BSMs) at 10 Hz with GPS position, velocity, heading, acceleration, and brake status. The Pedestrian Layer adds Vulnerable Road User (VRU) awareness through ETSI ITS VRU standards, integrating Smartphone VRU Apps and BLE/C-V2X Wearable Devices for enhanced safety. This multi-protocol, multi-layer design demonstrates best practices for heterogeneous V2X deployments, balancing DSRC legacy support with modern C-V2X cellular connectivity while protecting vulnerable road users. Fork this diagram on Diagrams.so to customize RSU placement, add additional vehicle types, or model alternative communication protocols for your regional ITS deployment.