Needing to use the washroom while at work

Marsha

So I work on the school buses and oh my lord, always around 2-230ish is the time when I really gotta pee, problem is I have students on board which I can’t just pulled over run into the gas station and let my bladder free, problem is I do not drink anything during the day only first in the morning when I wake up

How in the world can I train my bladder to hold off til 430-5ish.... May seem werid but is there any tricks to this without peeing myself