It's doesn't matter, it is not acceptable. They should refund everyone if the train is more than 15 seconds late. This is something a train can do with computer control, and good maintenance. A bus is harder to be on schedule for.
>refund everyone if the train is more than 15 seconds late
lol, it seems you have -100 knowledge how complicated rail systems could be
That complexity must be tamed in the office. It is hard for sure. But if the schedule isn't carefully planned with the right margins you can't run a system people trust.