Density-Based Traffic Light Controller using Arduino

The Density-Based Traffic Light Controller operates by measuring real-time vehicle presence and density at an intersection using a network of HC-SR04 ultrasonic sensors. Each sensor transmits high-frequency sound waves and measures the echo return time to calculate the distance of oncoming vehicles. The Arduino Uno and Arduino Nano boards process these distance measurements simultaneously. When a sensor detects vehicles within a specific threshold distance, it registers high traffic density for that particular lane. The system's central logic evaluates the density across all monitored directions and dynamically adjusts the duration of the green light for each lane. By allocating longer green times to congested lanes and shorter intervals to empty lanes, the traffic flow is optimized. Visual output is provided by common cathode RGB LEDs, which function as the traffic signals, transitioning through standard red, yellow, and green states based on the microcontrollers' real-time timing decisions. Jumper wires and breadboards establish the necessary circuit connections and power distribution among the sensors, LEDs, and microcontroller pins.