Final answer:
When a bus or truck approaches a railroad crossing, you should stop and wait for it to cross for safety reasons. Never continue driving or use your horn in such situations.
Step-by-step explanation:
If a bus or truck is approaching a railroad crossing, the proper action to take is to stop and wait for the bus or truck to cross. This is because buses and trucks often have to stop at railroad crossings, especially if they are carrying passengers or hazardous materials, for safety reasons.
As a driver, you should never ignore the bus or truck and continue driving, nor should you honk your horn to alert the bus or truck as your horn could be mistaken for a train signal. Always prioritize safety and adhere to legal requirements and road safety rules when approaching a railroad crossing. By stopping and waiting, you ensure not only your own safety but also that of the passengers on the bus or truck and other road users.