Two-way (Opposite-Facing) Traffic Light System

In this project, we are creating a Two-way Traffic Light system to control the flow of cars coming from two different directions. The primary objectives of this system are:

State 1: One side of the road will display a green light, allowing traffic to pass, while the opposing side shows a red light, indicating that traffic must stop.

State 2: The green light from the first side will change to yellow for a short period, then to red. After a short delay to allow the last cars to clear the section, the second side will switch to green, allowing traffic to flow in the opposite direction.

Components Required

Arduino UNO
6 LEDs
6 220Ω Resistors
Breadboard
Jumper Wires
Arduino UNO
LED
220Ω Resistor
Breadboard
Jumper Wires

Circuit Diagram

Arduino Program Code

Download the Arduino Program Code for the Two-way Traffic Light Signal.

// Two-Way Traffic Light System
// Road A: Red, Yellow, Green
// Road B: Red, Yellow, Green

// Define pins for Road A
int redA = 2;
int yellowA = 3;
int greenA = 4;

// Define pins for Road B
int redB = 5;
int yellowB = 6;
int greenB = 7;

void setup() {
  // Set all pins as OUTPUT
  pinMode(redA, OUTPUT);
  pinMode(yellowA, OUTPUT);
  pinMode(greenA, OUTPUT);

  pinMode(redB, OUTPUT);
  pinMode(yellowB, OUTPUT);
  pinMode(greenB, OUTPUT);
}

void loop() {
  // Step 1: Road A GREEN, Road B RED
  digitalWrite(greenA, HIGH);
  digitalWrite(redA, LOW);
  digitalWrite(yellowA, LOW);

  digitalWrite(redB, HIGH);
  digitalWrite(yellowB, LOW);
  digitalWrite(greenB, LOW);
  delay(5000); // A road green for 5 seconds

  // Step 2: Road A YELLOW, Road B RED
  digitalWrite(greenA, LOW);
  digitalWrite(yellowA, HIGH);
  digitalWrite(redA, LOW);

  digitalWrite(redB, HIGH);
  digitalWrite(yellowB, LOW);
  digitalWrite(greenB, LOW);
  delay(2000); // A yellow for 2 seconds

  // Step 3: Road A RED, Road B GREEN
  digitalWrite(redA, HIGH);
  digitalWrite(yellowA, LOW);
  digitalWrite(greenA, LOW);

  digitalWrite(greenB, HIGH);
  digitalWrite(yellowB, LOW);
  digitalWrite(redB, LOW);
  delay(5000); // B road green for 5 seconds

  // Step 4: Road A RED, Road B YELLOW
  digitalWrite(redA, HIGH);
  digitalWrite(yellowA, LOW);
  digitalWrite(greenA, LOW);

  digitalWrite(greenB, LOW);
  digitalWrite(yellowB, HIGH);
  digitalWrite(redB, LOW);
  delay(2000); // B yellow for 2 seconds

  // Repeat cycle
}

Output