PLC based traffic control system with emergency vehicle detection and management

This paper depicts the design of an automated traffic control system with a distinctive attribute of emergency vehicle control. Upon being interrupted by an emergency signal, the system automatically retains the state of the normal sequence and gives the corresponding road a green light signal as long as the emergency signal is high. As soon as the emergency signal becomes low, the system instantly jumps back to the retained state of the normal sequence. Emergency Signal detection is RFID based. The system is designed using Programmable Logic Controller (PLC) ladder logic program. The system was implemented in a PLC simulated environment. Later, it was tested in a hardware prototype. The test results indicated that it can be implemented in the real world without altering the original code. This PLC based system can be used to replace the conventional traffic control system. By including additional input and output modules into the PLC system, this system can be easily extended to dynamically manage the traffic system of an entire city.