/*
MODIFIED TRAFFIC LIGHT SYSTEM W/ A COUNTDOWN TIMER FUNCTION
BY JOHN SEONG

THIS IS A QUITE ACCURATE SIMULATION OF TORONTO'S TRAFFIC LIGHT SYSTEM
WHICH INCLUDES TWO 7-SEGMENT DISPLAYS THAT SHOW THE SECONDS LEFT
TILL THE PEDESTRIAN LIGHT SWITCHES BACK TO RED.

ENJOY!
*/

const int redLED = 4;
const int yellowLED = 5;
const int greenLED = 6;
const int pedestrianRedLED = 13;
const int pedestrianGreenLED = A5;
const int buzzer = 12;
const int button = 7;

int segmentPins[] = {11, 10, 9, 8};

int buttonHitCount = 0;

void setup() {
  
  Serial.begin(9600);
  
  // Car Traffic LEDs
  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  
  // Pedestrian Traffic LEDs
  pinMode(pedestrianRedLED, OUTPUT);
  pinMode(pedestrianGreenLED, OUTPUT);
  
  // 7-Segment Display Pins
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(8, OUTPUT);
  
  // Piezo Speaker Pin
  pinMode(buzzer, OUTPUT);
  
  // Pedestrian Push Button
  pinMode(button, INPUT_PULLUP);
  
  displayNumber(9, 2);
  displayNumber(9, 3);
}

void loop() {
  
  // Read the state of the button
  int buttonState = digitalRead(button);
  
  Serial.println(buttonState);
  
  if (buttonState == LOW) {
    buttonHitCount = 1;
  }
  
  if (buttonHitCount == 1) {
    switchToRed();
    
  } else if (buttonHitCount == 0) {
    defaultState();
  }
}

void displayNumber(int num, int displayPin) {
  
  bool binaryValue[][4] = {
    {0, 0, 0, 0}, // 0
    {0, 0, 0, 1}, // 1
    {0, 0, 1, 0}, // 2
    {0, 0, 1, 1}, // 3
    {0, 1, 0, 0}, // 4
    {0, 1, 0, 1}, // 5
    {0, 1, 1, 0}, // 6
    {0, 1, 1, 1}, // 7
    {1, 0, 0, 0}, // 8
    {1, 0, 0, 1}, // 9
  };
  
  for(int i = 0; i < 4; i++) {
    digitalWrite(segmentPins[i], binaryValue[num][i]);
  }
  
  digitalWrite(displayPin, HIGH);
  delayMicroseconds(10);
  
  digitalWrite(displayPin, LOW);
}

void switchToRed() {
  
  delay(5000);
  
  // YELLOW
  digitalWrite(yellowLED, HIGH);
  digitalWrite(redLED, LOW);
  digitalWrite(greenLED, LOW);
  delay(2000);
  
  // RED
  digitalWrite(redLED, HIGH);
  digitalWrite(greenLED, LOW);
  digitalWrite(yellowLED, LOW);
  
  // GREEN
  digitalWrite(pedestrianGreenLED, HIGH);
  digitalWrite(pedestrianRedLED, LOW);
  
  switchToGreen();
}

void switchToGreen() {
  
  // 15
  noTone(buzzer);
  displayNumber(1, 2);
  displayNumber(5, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 14
  noTone(buzzer);
  displayNumber(1, 2);
  displayNumber(4, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 13
  noTone(buzzer);
  displayNumber(1, 2);
  displayNumber(3, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 12
  noTone(buzzer);
  displayNumber(1, 2);
  displayNumber(2, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 11
  noTone(buzzer);
  displayNumber(1, 2);
  displayNumber(1, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 10
  noTone(buzzer);
  displayNumber(1, 2);
  displayNumber(0, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 9
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(9, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 8
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(8, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 7
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(7, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 6
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(6, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 5
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(5, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 4
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(4, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 3
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(3, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 2
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(2, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  // 1
  noTone(buzzer);
  displayNumber(0, 2);
  displayNumber(1, 3);
  tone(buzzer, 1000);
  delay(1000);
  
  noTone(buzzer);
  
  // YELLOW
  digitalWrite(yellowLED, HIGH);
  digitalWrite(redLED, LOW);
  digitalWrite(greenLED, LOW);
  delay(2000);
  
  // GREEN
  digitalWrite(redLED, LOW);
  digitalWrite(greenLED, HIGH);
  digitalWrite(yellowLED, LOW);
  
  // PEDESTRIAN - RED
  digitalWrite(pedestrianGreenLED, LOW);
  digitalWrite(pedestrianRedLED, HIGH);
  
  // Reset the value
  buttonHitCount = 0;
}

void defaultState() {
    
    // GREEN
    digitalWrite(greenLED, HIGH);
    digitalWrite(yellowLED, LOW);
    digitalWrite(redLED, LOW);
    
    // PEDESTRIAN - RED
    digitalWrite(pedestrianRedLED, HIGH);
    digitalWrite(pedestrianGreenLED, LOW);
}

Clearly something is wrong with my code and the 7-segment displays are off the whole time the program is running. I also posted a link below which directs to the tinkercad project I made.

https://www.tinkercad.com/things/7pnnbXoaqrG-improved-stop-light-john-seong/editel?sharecode=jR86i_srV7QgP11u1CxOFzeVwehzjIRr8wCC7vbbLaY