Smart Traffic Signal System - Electronic Engineering Guide
1. Introduction
The Smart Traffic Signal System aims to intelligently control traffic lights based on real-time traffic conditions. It utilizes sensors and microcontrollers to minimize congestion and waiting time at intersections, offering an efficient and adaptive traffic management solution.
2. Objectives
• To dynamically control traffic signals based on traffic
density.
• To reduce unnecessary waiting time and traffic congestion.
• To improve fuel efficiency and road safety.
3. Components Required
• Arduino Uno or any suitable microcontroller
• IR sensors or Ultrasonic sensors (for vehicle detection)
• LEDs (Red, Yellow, Green) for traffic lights
• Resistors and breadboard
• Power supply or USB cable
• Optional: GSM or Wi-Fi module for remote monitoring
• Real-Time Clock (RTC) module for time-based scheduling
4. System Overview
The system detects the presence and number of vehicles using IR or ultrasonic sensors and adjusts the signal timings accordingly. It cycles through signals based on queue length or predefined priorities, enhancing overall traffic flow efficiency.
5. Sensor and Microcontroller Integration
IR sensors are installed at each lane to detect vehicle presence. These are connected to digital input pins of the microcontroller. The microcontroller reads the data and controls LEDs representing traffic signals based on the traffic density.
6. Circuit Design and Operation
Each IR sensor is connected to a digital pin on the Arduino,
and the traffic lights are connected to output pins. When a sensor detects
vehicles, the controller prioritizes that lane.
Example:
• IR Sensor 1 → D2
• IR Sensor 2 → D3
• Red LED → D8
• Yellow LED → D9
• Green LED → D10
7. Software and Code Explanation
The Arduino IDE is used for programming. Based on sensor
inputs, the program determines which signal stays green the longest.
Example Code Snippet:
int ir1 = 2, ir2 = 3;
int red = 8, yellow = 9, green = 10;
void setup() {
pinMode(ir1, INPUT);
pinMode(ir2, INPUT);
pinMode(red, OUTPUT);
pinMode(yellow, OUTPUT);
pinMode(green, OUTPUT);
Serial.begin(9600);
}
void loop() {
int t1 = digitalRead(ir1);
int t2 = digitalRead(ir2);
if (t1 == HIGH) {
digitalWrite(green, HIGH);
digitalWrite(red, LOW);
} else if (t2 == HIGH) {
digitalWrite(red, HIGH);
digitalWrite(green, LOW);
} else {
digitalWrite(yellow, HIGH);
delay(1000);
digitalWrite(yellow, LOW);
}
delay(1000);
}
8. Applications
• Urban and metropolitan traffic management
• Emergency vehicle priority systems
• Smart city development initiatives
• Event traffic and temporary signal deployment
9. Challenges and Future Enhancements
• Sensor misreads in harsh weather conditions.
• Requires calibration and maintenance.
• Can be enhanced with camera-based AI vehicle detection.
• Add V2X communication for connected vehicles.
• Integrate with central traffic control systems.
10. Conclusion
The Smart Traffic Signal System provides an adaptive approach to managing urban traffic efficiently. By automating signal timing based on real-time conditions, it reduces congestion, saves fuel, and improves traffic flow.