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

Selling tickets and managing the timetable

Answer

Checking luggage for prohibited items

Answer

Keeping to the timetable — passenger safety is a conductor's responsibility

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

10 standing passengers for any urban bus

Answer

Equal to the seated capacity — standing and seated numbers are always equal

Answer

Standing is prohibited on all service buses in Ireland

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

Whenever the driver considers the passenger unsuitable

Answer

When the passenger lacks the correct fare and no alternative payment is available

Answer

Boarding refusal is only at the discretion of the transport company

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

A brake system that uses air cooling to prevent brake fade

Answer

An electrically operated braking system for large vehicles

Answer

A braking system that vents brake heat through air ducts

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

A soft application brake for gentle deceleration in traffic

Answer

A brake applied only to the front axle for directional stability

Answer

An emergency brake operated by a separate foot pedal

Question 6

What is the minimum air pressure required before driving an air-braked vehicle?

Accepted Answer

The pressure must reach the cut-in pressure shown in the vehicle manual — typically around 5-6 bar — and brake warning lights must extinguish

Answer

Any reading above 0 bar — the system builds pressure while driving

Answer

3 bar minimum — this is the emergency brake activation threshold

Answer

7 bar — the maximum operating pressure before a safety valve opens