Traffic Light Sequence

int LED1 = 5;
int LED2 = 6;
int LED3 = 7;
int LED4 = 8;
int LED5 = 9;
int LED6 = 10;
int speed1 = 7500;
int speed2 = 1500;
int speed3 = 1000;


void setup(){
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  pinMode(LED5, OUTPUT);
  pinMode(LED6, OUTPUT);
}

void loop(){
  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, HIGH);
  digitalWrite(LED5, LOW);
  digitalWrite(LED6, LOW);
  delay(speed1);


  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  digitalWrite(LED5, HIGH);
  digitalWrite(LED6, LOW);
  delay(speed2);


  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  digitalWrite(LED5, LOW);
  digitalWrite(LED6, HIGH);
  delay(speed3);


  digitalWrite(LED1, LOW);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, HIGH);
  digitalWrite(LED4, LOW);
  digitalWrite(LED5, LOW);
  digitalWrite(LED6, HIGH);
  delay(speed1);


  digitalWrite(LED1, LOW);
  digitalWrite(LED2, HIGH);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  digitalWrite(LED5, LOW);
  digitalWrite(LED6, HIGH);
  delay(speed2);


  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  digitalWrite(LED5, LOW);
  digitalWrite(LED6, HIGH);
  delay(speed3);
}