ECHO: An Explainable Cooperative Highway Operator for Human-Centric ADAS

ECHO is a next-generation advanced driverassistance system (ADAS) that integrates multi-modal perception, cooperative V2X communication, and an agentic large language model (LLM) for explainable, human-centric support. Unlike traditional ADAS, ECHO does not directly control the vehicle but interprets real-time data from sensors, infrastructure, and driver state, producing transparent natural language guidance and standardized V2X intent messages. Extensive evaluation in both simulation and real-world settings shows that ECHO reduces reaction times to V2X events by over 40 %, decreases near-miss incidents by 60 %, and significantly enhances cooperative maneuver success compared to conventional ADAS. These results demonstrate the potential of agentic, explainable AI to advance connected mobility with improved safety, trust, and driver engagement.