This document describes a proposed smart traffic signal monitoring and controlling system using IoT. The system would allow prioritized passage for emergency vehicles like ambulances by detecting them using RFID tags and cameras. When an ambulance is detected, the traffic signals on its route would automatically switch to green to allow smooth passage until the ambulance passes through. The system aims to help emergency vehicles avoid traffic and reach their destinations faster. It would also provide information to users through a mobile app about traffic conditions and the fastest routes.