ATM

It was a Monday morning, so he was expecting a large queue in front of the ATM. But he had to take out money for his personal use urgently. He drove aimlessly for a while, expecting to find an empty ATM but he knew that he wouldn’t be able to find one on a busy morning. So he gave up and stood in the long queue of the ATM in his neighborhood after parking his car aside. How long would he have to wait before his turn comes up?