Around here the protocol is apparently three short blasts of the horn, followed by three long blasts, followed by three short blasts when approaching a crossing. Every crossing.
Every. single. crossing.
There are
seven crossings within 3/4 of a mile of my house.
They blow the horn there (nine times), and there (nine times), and there (nine times), and there (nine times), and there (nine times), and there (nine times), and there...nine times.
No matter the time.