DTT HGV Passenger Safety and Air Brakes 2

Question 1

What happens to an air-braked vehicle if it runs out of compressed air pressure while driving?

Accepted Answer

The spring brakes apply automatically — bringing the vehicle to an emergency stop

Answer

When air pressure drops to a critical level, the spring brakes apply automatically. This is a safety feature — the vehicle stops automatically rather than losing braking capability. The driver will experience a sudden stop.

Question 2

How should a bus driver manage standing passengers when braking?

Accepted Answer

Brake smoothly and progressively to allow standing passengers to brace — avoid sudden stops that could cause them to fall

Answer

Standing passengers are vulnerable to sudden braking. A professional bus driver uses smooth, progressive braking to minimise sudden forces on passengers who cannot brace as effectively as seated occupants.

Question 3

What is the purpose of a 'brake test' when taking over an air-braked vehicle?

Accepted Answer

To confirm that the service brakes, spring brakes, and warning systems all function correctly before driving on public roads

Answer

A static brake test checks that air pressure builds correctly, warning lights extinguish at correct pressure, and that both service and spring brakes function. It must be done before every journey in an air-braked vehicle.

Question 4

What should a bus driver do if a passenger becomes seriously ill during a journey?

Accepted Answer

Stop the vehicle safely, call emergency services, administer first aid if trained, and keep passengers calm until help arrives

Answer

A driver has a duty of care to all passengers. In a medical emergency, stop safely, call 999, administer basic first aid if trained, and protect the patient and other passengers while awaiting emergency services.

Question 5

What are the brake fade risks specific to heavily loaded trucks descending steep hills?

Accepted Answer

Continuous heavy braking overheats brake drums — brake fade reduces stopping power, potentially causing loss of control

Answer

Even air brakes can fade if brake drums overheat through continuous heavy use on long descents. Experienced truck drivers use engine braking (low gears) on long descents to protect the brakes.

Irish DTT Truck/Bus Practice Test

Irish DTT Truck/Bus Practice Test

DTT HGV Passenger Safety and Air Brakes 2