DTT HGV Motorway Driving and CPC Requirements

Question 1

What is the maximum speed limit for trucks over 3.5 tonnes on an Irish motorway?

Accepted Answer

90 km/h — enforced by the mandatory speed limiter

Answer

Trucks over 3.5 tonnes are limited to 90 km/h on Irish motorways by mandatory speed limiters. This limit applies regardless of the posted motorway limit of 120 km/h for cars.

Question 2

What lanes are trucks permitted to use on a three-lane motorway in Ireland?

Accepted Answer

Lane 1 (nearside/left) and lane 2 (middle) — lane 3 (offside/right) is restricted to cars and certain vehicles only

Answer

On a three-lane motorway, trucks over 7.5 tonnes are generally restricted from using the outer (right-hand) lane unless it is necessary to do so in exceptional circumstances. They should use lanes 1 and 2 only.

Question 3

What must a truck or bus driver do before joining a motorway from a slip road?

Accepted Answer

Accelerate to match motorway traffic speed on the slip road, check mirrors and blind spots, and merge safely into a gap in the left lane

Answer

Use the full length of the slip road to reach motorway speed, carry out MSM routine (mirrors, signal, manoeuvre), check the blind spot, and merge smoothly into a gap. Merging slowly disrupts motorway traffic and is dangerous.

Question 4

What is the procedure when a truck's load shifts during motorway driving?

Accepted Answer

Move to the hard shoulder safely, stop, switch on hazard lights, and secure the load before continuing — do not continue with an unstable load

Answer

A shifted load changes the vehicle's handling, weight distribution, and may be in imminent danger of falling. Stop on the hard shoulder immediately, use hazard lights and warning triangles, and secure the load before proceeding.

Question 5

What is the correct response when a tyre blows out on a truck travelling on a motorway?

Accepted Answer

Grip the steering firmly, ease off the throttle gradually, do not brake sharply, steer to the hard shoulder, and stop safely

Answer

A tyre blowout on a heavy vehicle at speed causes a sudden pull toward the affected side. Resist braking immediately — firm wheel grip and gradual deceleration gives the best chance of maintaining control while pulling over.

Irish DTT Truck/Bus Practice Test

Irish DTT Truck/Bus Practice Test

DTT HGV Motorway Driving and CPC Requirements