What is the highest priority alarm on a bus?

The highest priority alarm on a bus is the emergency alarm. This alarm is used to signal a critical situation that requires immediate attention and response, either from the driver, passengers, or emergency services. When the emergency alarm is activated, it indicates a potentially dangerous situation, such as an accident or medical emergency, and helps ensure the safety of everyone on board.

In contrast, the silent alarm is typically used for discreet reporting of incidents. While it serves an important function, its purpose does not carry the same level of urgency as an emergency alarm. The mechanical alarm informs the driver of technical issues that may affect the bus's operational integrity but does not signal an immediate threat to safety. Lastly, a service alarm relates to general operational issues, which, while important, do not pertain to emergencies that necessitate immediate action.