TheoryHGV Theory UK Study Guide
Study for the HGV Theory UK with exam topics, practice questions, a free PDF, video walkthrough and timed mock exam links.
How to study for HGV Theory UK
- Read the topic list so you know what the exam is likely to cover.
- Answer the free practice questions and read every explanation.
- Download the PDF for offline review.
- Use timed mock exams when your untimed practice feels comfortable.
Topics to review
- Road signs, signals and markings
- Right-of-way and intersection rules
- Speed, stopping distances and safe following
- Hazard perception and defensive driving
Try HGV Theory UK questions now
Q1You are driving a fully laden articulated lorry down a long, steep gradient. The retarder has been active for several minutes and you notice it is becoming less effective. What is the most likely cause?
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✓ Correct answer: The retarder oil has become overheated and lost viscosity
Retarders (hydraulic or electromagnetic) generate heat when absorbing kinetic energy; prolonged use causes the fluid or components to overheat, reducing braking effectiveness — the driver should use lower gears and allow cooling rather than relying solely on the retarder.
Q2An articulated vehicle with a 13.6 m semi-trailer is negotiating a tight left-hand roundabout. The driver positions the cab close to the right-hand kerb before turning. Why?
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✓ Correct answer: To allow the trailer's rear overhang to clear the left-hand kerb during the turn
The swept path of a long semi-trailer means the rear wheels cut significantly inward on a left turn; by swinging the cab rightward first, the driver increases the radius the trailer tyres follow, preventing the rear corner from mounting or striking the left-hand kerb.
Q3You are about to drive under a railway bridge. Your loaded vehicle is 4.1 metres high and the posted clearance is 4.2 metres. What should you do?
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✓ Correct answer: Find an alternative route, because posted clearances include no tolerance and your load measurement may not be exact
DVSA guidance warns that posted bridge heights are nominal minimums and load heights measured at rest can increase due to road camber, suspension sag changes, or measurement error — a margin of only 100 mm is unsafe and an alternative route should be used.
Q4You are descending a steep hill in a 44-tonne vehicle. You selected the correct gear at the top, but your speed is now creeping above the safe limit. What is the FIRST corrective action you should take?
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✓ Correct answer: Apply steady progressive pressure to the service brake and, once speed is controlled, change to a lower gear if necessary
The DVSA advises using progressive service braking to control speed on descents and only changing to a lower gear once speed is already controlled — attempting to downshift while accelerating risks transmission damage and loss of control.
Q5When driving a long vehicle, you notice that the nearside rear wheels are tracking over a raised kerb during a left turn at a junction. What does this indicate about your line choice?
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✓ Correct answer: You turned too early, causing the trailer to cut in
Turning the steering too early on a left bend reduces the arc available to the trailer wheels, causing the rear to cut inward and mount the kerb — the correct technique is to delay the turn and take a wider initial line.
Q6You are driving a PCV with a high centre of gravity on a cambered rural road. The nearside wheels begin to follow a dip in the road surface. What specific risk does this create for this vehicle type?
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✓ Correct answer: The camber reduces effective tyre contact area, increasing rollover risk
A high-sided PCV has a high centre of gravity; when nearside wheels drop into a road dip, the vehicle's effective lean angle increases and the stability margin against rollover is significantly reduced — drivers must maintain appropriate speed and smooth steering.
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