One of my least favorite parts of school was being told 'Why didn't you go the restroom or locker between classes'?
The school is huge. I can't even get to my classes on time if I walk without a detour. Then you'll write me up anyways. We have about 2 minutes and 30 seconds. It doesn't help if my locker is on another side of the building.
It was infuriating and I don't miss that at all.
I had a teacher who would stand near the door and lock it the moment the bell rang. She said we weren't allowed in so we had to explain why we were late to the principal and get a form signed to enter back into her class. Sometimes I was simply late because kids were blocking the hallway and chatting. I physically could do nothing about that.
Sometimes it's not the kids who are problematic. It's unfortunately adults too.