CarTraC: A Lightweight IoT-Based System for Post-Crash Accountability in Hit-and-Run Incidents

CarTraC is a post-crash evidence-sharing proof-of-concept system for hit-and-run incidents, to cooperatively exchange crash data through direct V2V communication. The proposed architecture focuses on an overlooked aspect of V2V systems, post-crash evidence sharing, while prior research focuses on pre-crash safety. CarTraC detects collisions by monitoring motion data and upon detection automatically broadcasts encrypted and signed messages to nearby vehicles. These messages contain crash-related and vehicle-specific information retrievable by trusted authorities. The system operates without cellular networks or roadside infrastructure and supports two modes: Self-CarTraC, for direct data exchange, and Cooperative-CarTraC, where uninvolved vehicles assist in rebroadcasting. The security properties of the CarTraC protocol were formally verified using ProVerif. A proof-of-concept prototype was implemented on a custom ESP32-based embedded platform equipped with inertial sensors and a 2.4 GHz transceiver. Experimental validation was conducted using two stationary vehicles in an outdoor semi-urban environment, demonstrating reliable post-crash data exchange without external connectivity. The implementation achieved delivery rates of up to 100% at 15 m and 70% at 85 m, with end-to-end latencies below 34 ms.