DTT HGV Passenger Safety and Air Brakes

Question 1

What is the driver of a bus or coach primarily responsible for regarding passenger safety?

Accepted Answer

Ensuring passengers board and alight safely, are seated before moving, do not stand in unauthorised areas, and are not endangered by the driver's actions

Answer

The driver is ultimately responsible for passenger safety. This includes ensuring all passengers are properly seated or holding before moving, maintaining safe driving conduct, and managing emergency situations.

Question 2

What is the maximum standing capacity in a standard single-deck urban bus?

Accepted Answer

Determined by the vehicle's type approval — standing passengers must have adequate handholds and space per person

Answer

Standing passenger capacity is set by the vehicle's type approval certificate. The number is calculated based on floor space, handrail provision, and safety standards. It varies by vehicle type and is marked in the vehicle.

Question 3

When must a bus driver not allow a passenger to board?

Accepted Answer

When the vehicle is at its certified maximum capacity, or the passenger's behaviour poses a safety risk

Answer

A driver must refuse boarding when the vehicle is at maximum capacity (standing or seated, per type approval). A driver may also refuse a passenger who is intoxicated, threatening, or whose presence endangers other passengers.

Question 4

What is an air brake system and why is it used on heavy vehicles?

Accepted Answer

A braking system powered by compressed air — used on heavy vehicles because air provides the force needed to apply large drum or disc brakes on multiple axles

Answer

Air brakes use compressed air to apply braking force to all axles simultaneously. The air pressure provides the power needed to brake very heavy vehicles — hydraulic systems do not generate sufficient force for multi-axle trucks and buses.

Question 5

What is the 'spring brake' (parking brake) on an air brake system?

Accepted Answer

A spring-loaded device that applies the brakes automatically when air pressure is lost — it holds the vehicle when parked

Answer

The spring brake (parking or emergency brake) on an air brake system is spring-loaded. When air pressure is released or lost, the spring force automatically applies the brakes — providing both parking and emergency brake functions.

Irish DTT Truck/Bus Practice Test

Irish DTT Truck/Bus Practice Test

DTT HGV Passenger Safety and Air Brakes