The number of vehicular collisions is on a toll worldwide. Despite enforcing stringent laws and incorporating various safety features, the causalities are still on the rise. Existing techniques such as vision zero strategy and safe system approach provides only postcrash aid. Although numerous works have been carried out on Intelligent Transportation Systems (ITS), a well-coordinated vehicular collision avoidance system is still missing. In this paper, we utilize the tremendous opportunity provided by ITS, Light Detection and Ranging (LIDAR), Wireless Sensor Networks (WSN), 5G, and propose an effective system using drones with swarm intelligence that can automatically control the vehicles to prevent the collision. The proposed method, Bidirectional Multi- Tier IoT drone with Swarm optimization (BMTD-IoT-S) uses intelligent coordination of the drone swarms with the vehicular networks and always ensures a safe distance between the vehicles using the principle of magnetic levitation. The system is further investigated for optimizing the power, altitude, and angular frequency allocation for static and dynamic BMTD-IoT-S'. The results from simulation confirm the excellent performance of the system in ensuring collision avoidance. © 2020 Association for Computing Machinery.