What should you know about using the emergency operation of bus doors?

The combination of options 1 and 2 you've selected is correct because it reflects the functionality and risks associated with the emergency operation of bus doors as per German traffic regulations.

1. The emergency operation is designed to allow anyone inside the bus to exit in case of accidents or breakdowns, ensuring safety and quick evacuation. This is essential in emergencies where staying inside could be dangerous.

2. However, there is a significant risk if this feature is misused; it can lead to the doors being opened while the bus is in motion, which poses a serious safety hazard for passengers and others on the road.

It's crucial to understand that while the emergency door operation is vital for safety, its misuse can have dangerous consequences, hence the need for strict regulations governing its use. Options 3, about door release only by the driver, is not included in the correct answer as it's not applicable in emergencies where quick evacuation is necessary. Thus, recognizing the balance between access and safety is key in German traffic law regarding public transportation.