int led_red1=4;
int led_yellow1 =5;
int led_green1=6;
int led_red2=7;
int led_yellow2 =8;
int led_green2=9;
void setup()
{ 
 pinMode(led_red1, OUTPUT);
 pinMode(led_yellow1, OUTPUT);
 pinMode(led_green1, OUTPUT);
 pinMode(led_red2, OUTPUT);
 pinMode(led_yellow2, OUTPUT);
 pinMode(led_green2, OUTPUT);
 }
void loop()
{ 
digitalWrite(led_red1, HIGH);// signal1 red is on
digitalWrite(led_green2, HIGH);//signa2 green is on
digitalWrite(led_red2, LOW);
digitalWrite(led_green1, LOW);
digitalWrite(led_yellow2, LOW);
digitalWrite(led_yellow1, LOW);
delay (2000);
digitalWrite(led_yellow2, HIGH);
delay (500);
digitalWrite(led_yellow2, LOW);
delay (500);
digitalWrite(led_green1, HIGH);//signa1 green is on
digitalWrite(led_red2, HIGH);// signal2 red is on
digitalWrite(led_red1, LOW);
digitalWrite(led_green2, LOW);
digitalWrite(led_yellow2, LOW);
digitalWrite(led_yellow1, LOW);
delay (2000);
digitalWrite(led_yellow1, HIGH);
  delay (500);
digitalWrite(led_yellow1, LOW);
delay (500);

}