Arduino Simple Traffic Light

Using the same development environment (Kali Linux 2.0 + Arduino IDE), we can build a simple traffic light. The setup can be referenced here, just the three LEDs wired with resistors to three separate input pins, and all connected to the ground.  (http://www.makeuseof.com/tag/arduino-traffic-light-controller/)

The sample sequence as following:
Red (5s)
Red + Yellow (2s)
Green  (5s)
Yellow (2s)
Red (5s)... loop back again

The sample code:

 int red = 13; int yellow = 12; int green = 11;  
 void setup(){   
  pinMode(red,OUTPUT);   
  pinMode(yellow,OUTPUT);   
  pinMode(green,OUTPUT);   
 }  
 void loop(){   
  changeLights();   
 }    
 void changeLights(){   
  //red first  
  digitalWrite(red,HIGH);   
  digitalWrite(green,LOW);   
  digitalWrite(yellow,LOW);   
  delay(5000);    
  //red + yellow   
  digitalWrite(red,HIGH);   
  digitalWrite(yellow,HIGH);   
  digitalWrite(green,LOW);   
  delay(2000);  
  //green  
  digitalWrite(red,LOW);   
  digitalWrite(yellow,LOW);   
  digitalWrite(green,HIGH);   
  delay(5000);  
  //yellow  
  digitalWrite(red,LOW);   
  digitalWrite(yellow,HIGH);   
  digitalWrite(green,LOW);   
  delay(2000);  
 }