<p>This research work focused on an attempt to quickly detect the vehicle crash on a road and eventually alarming the vehicles approaching towards the crash site. The purpose is to stop the subsequent collision of the fast-approaching vehicle in a challenging situation of poor visibility due to fog. The solution proposed to the problem is an integration of embedded system and sensor network encapsulated into a road stud. Each road stud are designed to sense the crash and signal the event to other studs to alert the vehicles coming on both direction of road. This research work considered factors such as the coverage area for sensing, power efficient methods and a reliable communication protocol. The coverage area is addressed for straight road and curvatures. The Power management is attained through adopting a proper Sleep/idle/Active switching mechanism and along with a low-power-long-term use strategy. A modified Sensor-Medium Access Control (S-MAC) is implemented in this proposed work. The system is tested for sensing and attained an accuracy of 97% for 0.5 m of crash occurrence distance. The value further reduced to 75% as it approached to 3.9 m. The number of nodes activated for same crash with various curvatures of road is investigated. Packet delivery ratio, average latency, collision rate, queue drop and scalability test have been performed upon the proposed system. Furthermore, the system is tested for its intended operation under various environmental conditions. The proposed system can be implemented in any road condition where sensing of crash and alerting is the top priority.</p>