My dad was a firefighter and he spend many long nights studying for promotion tests. I liked to read some of the question books as a kid, especially the stuff about mass cuasilties.
But I only remember one question: “a fire truck, ambulance, police car and mail truck get to an intersection at the same time. All are indicating they are responding to an emergency. Who has the right of way?”
The answer was the postal truck… it’s federal.