You are driving a truck and trailer with a common compressed air-braking system. What is the function of the handbrake valve control setting here?

The handbrake valve control setting is essential when driving a truck with a trailer. The correct combination of options indicates that the handbrake system uses the spring-loaded brakes on the towing vehicle to ensure safety while allowing the trailer's service brake to be released.

1. The towing vehicle is braked via the spring-loaded brakes: This is crucial for stopping the entire unit in a controlled manner, especially when parked or in emergency situations.

2. The service brake of the trailer is released: This shows that when the handbrake is engaged, it allows the trailer to roll freely if necessary.

Selecting both options emphasizes the importance of understanding how the braking system works for safety compliance according to German traffic laws, which are designed to ensure safe and effective vehicle operation in various conditions. Not recognizing or applying the correct settings can lead to safety hazards on the road.