Traffic jam is a serious problem in our life, it causes waste of time and energy, conventional traffic light control system works with a fixed time and fixed cycle. This paper proposes an intelligent traffic light control system with a changeable green time and cycle depending on traffic density. Traffic parameters (cars’ numbers, density, flow) are collected by Loop Detectors located at each traffic signal, this data will be transmitted to the PLC controller then, PLC processes this data to produce controlling commands, it is also connected to a SCADA system which supervises the process and provides an automatic and manual control. The proposal system applies Green Wave method to connect between two junctions based on a real car velocity and sets priority for emergency car, when Loop Detector detects this car the program will be interrupted to open the traffic light needed. This intelligent system is experimented with conventional control system s’ data the obtained result is promising, it can reduce the green time, cycle time, and delayed time of each car at traffic light to its’ minimum value.