Car Volume Based Traffic Light System using IR sensor (Arduino)

can someone give me advice about the code for this project

this is my sample code

int r1 = 1;// pin for the LED
int g1 = 2;
int r2 = 4;
int g2 = 5;
int r3 = 7;
int g3 = 8;
int r4 = 10;
int g4 = 11;
int y0 = 13;// all yellow LED are connected in parallel
int timer = 7000;// set initial timer for the system after first boot
int isObstaclePinA = 3;// pin for the IR sensor
int isObstaclePinB = 6;
int isObstaclePinC = 9;
int isObstaclePinD = 12;
int var = 0;

void setup () {
pinMode(r1, OUTPUT);
pinMode(g1, OUTPUT);
pinMode(r2, OUTPUT);
pinMode(g2, OUTPUT);
pinMode(r3, OUTPUT);
pinMode(g3, OUTPUT);
pinMode(r4, OUTPUT);
pinMode(g4, OUTPUT);
pinMode(y0, OUTPUT);
pinMode(isObstaclePinA, INPUT);
pinMode(isObstaclePinB, INPUT);
pinMode(isObstaclePinC, INPUT);
pinMode(isObstaclePinD, INPUT);

}



void loop () {

switch (var) { // for enabling the switch command

case 1:
if (isObstaclePinA == HIGH);
digitalWrite(isObstaclePinB, LOW);
digitalWrite(isObstaclePinC, LOW);
digitalWrite(isObstaclePinD, LOW);
digitalWrite(g1, HIGH);// LED lights on
digitalWrite(r1, LOW);
digitalWrite(r2, HIGH);
digitalWrite(r3, HIGH);
digitalWrite(r4, HIGH);
delay(timer); // time the lights will turn on

digitalWrite(y0, HIGH);
delay(3000); // time the yellow LED will light
for (isObstaclePinA == HIGH; timer < 50000; timer + 5000); // for adding seconds in the timer every time the sensor responds
break;

case 2: // next case
if (isObstaclePinB == HIGH);
digitalWrite(isObstaclePinA, LOW);
digitalWrite(isObstaclePinC, LOW);
digitalWrite(isObstaclePinD, LOW);
digitalWrite(g2, HIGH);
digitalWrite(r2, LOW);
digitalWrite(r1, HIGH);
digitalWrite(r3, HIGH);
digitalWrite(r4, HIGH);
delay(timer);

digitalWrite(y0, HIGH);
delay(3000);
for (isObstaclePinB == HIGH; timer < 50000; timer + 5000);
break;

case 3:
if (isObstaclePinC == HIGH);
digitalWrite(isObstaclePinB, LOW);
digitalWrite(isObstaclePinA, LOW);
digitalWrite(isObstaclePinD, LOW);
digitalWrite(g3, HIGH);
digitalWrite(r3, LOW);
digitalWrite(r1, HIGH);
digitalWrite(r2, HIGH);
digitalWrite(r4, HIGH);
delay(timer);

digitalWrite(y0, HIGH);
delay(3000);
for (isObstaclePinC == HIGH; timer < 50000; timer + 5000);
break;

case 4:
if (isObstaclePinD == HIGH);
digitalWrite(isObstaclePinB, LOW);
digitalWrite(isObstaclePinC, LOW);
digitalWrite(isObstaclePinA, LOW);
digitalWrite(g4, HIGH);
digitalWrite(r4, LOW);
digitalWrite(r1, HIGH);
digitalWrite(r2, HIGH);
digitalWrite(r3, HIGH);
delay(timer);

digitalWrite(y0, HIGH);
delay(3000);
for (isObstaclePinD == HIGH; timer < 50000; timer + 5000);
break;