Vehicle loading is one of the smaller theory test topics, but it is easy to lose marks on because the questions are specific. It covers how the weight you carry, including passengers, luggage, roof loads and trailers, changes the way a car handles, and the rules you must follow when you load up or tow. Even if you never tow a caravan, you will one day pack a car for a holiday or a house move, and this is the topic that tells you how to do it safely.
Last reviewed: September 2026. Checked against the Highway Code and GOV.UK.
What this topic covers in the theory test
Questions typically ask about:
- how extra weight affects steering, braking and stopping distances
- securing loads so they cannot move or fall off
- tyre pressures when a car is heavily loaded
- towing: what your licence allows, speed limits, motorway lanes and what to do if a trailer snakes
- carrying children and passengers safely, including child restraints
The main sources are Highway Code rules 98 to 102, the speed limit table in rule 124, Annex 6 on vehicle maintenance, and GOV.UK’s towing with a car guidance.
How weight changes the way a car behaves
A car is designed and tested with a certain load in mind. When you add heavy luggage, a full set of passengers, a roof box or a trailer, three things change.
- Braking. More weight means more energy to get rid of, so stopping distances increase. Rule 98 specifically warns that stopping distances increase when towing.
- Steering and stability. Weight high up (on a roof) or at the very back of the car makes it less stable, particularly in bends and crosswinds.
- Acceleration. A loaded car takes longer to pick up speed. Allow more time when overtaking, joining a main road or rejoining a motorway.
Because of this, the practical advice is to drive more gently when loaded: brake earlier, take bends more slowly and leave a bigger gap to the vehicle in front. Rule 126 already asks for at least a two-second gap on high-speed roads; with a heavy load or trailer, a larger gap makes sense.
Securing a load
Rule 98 says you MUST NOT overload your vehicle or trailer, and you MUST secure your load so that it does not stick out dangerously. Annex 6 adds that luggage should be securely stowed.
Why it matters: in a sudden stop, loose items keep moving at the speed the car was travelling. A bag on the parcel shelf or an unsecured box in the boot can be thrown forward into the people in the car. An insecure load on a roof rack or trailer can fall into the path of other traffic. The Highway Code even lists “an insecure load” as an example of something a traffic officer might stop you for (rule 108).
Practical points for the test and for real life:
- put heavy items low down and as far forward in the boot as possible
- use straps, nets or ties designed for the job, and check them after the first few miles
- do not block your view through the rear window or mirrors
- keep the load within the size and weight limits for your vehicle and any roof rack
Roof racks and roof boxes
A roof load raises the car’s centre of gravity and increases wind resistance. That makes the car more affected by crosswinds, less stable in bends and more expensive to run, because it uses more fuel. Only carry what you need on the roof, secure it well, and remove an empty rack or box when you no longer need it.
Tyre pressures and a heavy load
Annex 6 says tyres MUST be correctly inflated to the vehicle manufacturer’s specification for the load being carried. Many cars have two sets of pressures: one for normal use and a higher one for a full load. You will find them in the handbook and often on a sticker inside the driver’s door or fuel filler flap.
Check pressures when the tyres are cold, before a journey. Annex 6 notes that warm tyres give a misleading reading. The same annex sets the legal minimum tread depth for cars at 1.6 mm across the central three-quarters of the tread, around the entire circumference.
Heavy loads can also make the back of the car sit lower, which tilts the headlights upward. Rule 98 mentions adjusting headlights so they do not dazzle other road users, and many cars have a headlight-levelling control for this.
Towing a trailer or caravan
What your licence allows
GOV.UK says that if you passed your car test on or after 1 January 1997, you can tow a trailer weighing up to 3,500 kg MAM (maximum authorised mass). You must also stay within your car’s own towing limit, which you can find in the handbook or on the manufacturer’s plate. Rule 98 says you MUST NOT tow more than your licence permits.
GOV.UK also sets size limits: the maximum trailer width for any towing vehicle is 2.55 metres, and a vehicle with a MAM of 3,500 kg or less cannot tow a trailer longer than 7 metres.
Before you set off
Rule 98’s pre-towing checklist includes:
- the vehicle and trailer must be roadworthy, with legal tyres and working lights
- do not overload, and follow the manufacturer’s recommendations
- distribute the weight so heavy items are mainly over the axle(s), with a downward load on the tow ball
- secure the load so it does not stick out dangerously
- towing mirrors MUST be used if your car is narrower than the trailer or load, or if the trailer or load blocks your view to the rear
- the trailer MUST be fitted with a secondary coupling device, such as a safety chain
Speed limits when towing
Lower national speed limits apply when a car is towing a caravan or trailer (rule 124):
| Road type | Car or motorcycle | Car towing a caravan or trailer |
|---|---|---|
| Built-up area | 30 mph | 30 mph |
| Single carriageway | 60 mph | 50 mph |
| Dual carriageway | 70 mph | 60 mph |
| Motorway | 70 mph | 60 mph |
These are national limits. A lower limit shown on signs always applies.
Motorway lanes
On a motorway with three or more lanes, a vehicle towing a trailer MUST NOT use the right-hand lane, except in prescribed circumstances such as lane closures (rule 265).
Snaking and swerving
A caravan or trailer can start to swing from side to side, often called snaking, especially at higher speeds, downhill or in crosswinds. Rule 98 says if the trailer starts to swerve or snake, or you lose control, ease off the accelerator and reduce speed gently to regain control. Harsh braking or sharp steering can make it worse. Loading the trailer correctly, with the weight over the axle and a downward load on the tow ball, helps prevent snaking in the first place.
Carrying passengers and children
Passengers are part of your load, and the rules about them are tested here.
- Rule 99: drivers and passengers MUST wear a seat belt if one is fitted, unless they are exempt.
- Rule 100: the driver MUST make sure children under 14 wear a seat belt or sit in an approved child restraint. Children under 1.35 metres (about 4 feet 5 inches) tall generally need a child seat, booster seat or booster cushion suitable for their weight and height, until they reach 12 years old or that height, whichever comes first.
- Rule 101: you MUST NOT put a rear-facing baby seat in a seat protected by an active frontal airbag.
- Rule 102: make sure child restraints are fitted properly, let children get in and out on the kerb side, and use child safety locks where fitted.
Passengers aged 14 and over are responsible for wearing their own seat belt. The driver’s legal responsibility covers children under 14.
Common mistakes learners make
- Thinking the towing speed limit on a motorway is 70 mph. It is 60 mph.
- Choosing “brake firmly” when a trailer snakes. The Highway Code says ease off the accelerator and slow down gently.
- Forgetting that tyre pressures should be adjusted for the load, following the manufacturer’s figures.
- Loading heavy items high up or at the back. Heavy items belong low down and, on a trailer, over the axle.
- Using the right-hand lane of a three-lane motorway while towing.
- Assuming adult passengers are the driver’s legal responsibility for seat belts. The driver’s duty is for children under 14.
- Putting a rear-facing baby seat in front of an active airbag.
Quick-reference table
| Rule or limit | Figure or requirement | Source |
|---|---|---|
| Towing speed limit, single carriageway | 50 mph | Rule 124 |
| Towing speed limit, dual carriageway and motorway | 60 mph | Rule 124 |
| Right-hand lane, 3+ lane motorway | Must not be used when towing (except prescribed circumstances) | Rule 265 |
| Towing on a post-1997 car licence | Trailer up to 3,500 kg MAM | GOV.UK |
| Maximum trailer width | 2.55 metres | GOV.UK |
| Maximum trailer length (towing vehicle MAM up to 3,500 kg) | 7 metres | GOV.UK |
| Tyre pressure | To manufacturer’s spec for the load carried | Annex 6 |
| Minimum tread depth, cars | 1.6 mm | Annex 6 |
| Child restraint | Needed until 12 years old or 1.35 metres tall, whichever first | Rule 100 |
| Rear-facing baby seat | Never in front of an active airbag | Rule 101 |
Practice questions
These practice questions are written by Get Driving Test Ready to help you revise. They are not official DVSA questions.
Q1. You are towing a small trailer on a single carriageway where the national speed limit applies. What is your maximum speed?
A) 40 mph
B) 50 mph
C) 60 mph
D) 70 mph
Answer: B. Cars towing caravans or trailers have a limit of 50 mph on single carriageways and 60 mph on dual carriageways and motorways. (Highway Code rule 124)
Practise this on the road: On national speed limit roads, practise naming the limit for a car, and for a car towing, on that road.
Q2. The caravan you are towing starts to snake from side to side on a downhill stretch. What should you do?
A) Brake hard to stop quickly.
B) Accelerate to pull the caravan straight.
C) Steer sharply in the opposite direction.
D) Ease off the accelerator and reduce speed gently.
Answer: D. Rule 98 says to ease off the accelerator and reduce speed gently to regain control. (Highway Code rule 98)
Practise this on the road: Discuss with your supervisor why smooth, gentle use of the accelerator and brakes matters when a car is heavily loaded.
Q3. You are loading your car for a long holiday with four passengers. What should you check about the tyres?
A) That they are slightly under-inflated for extra grip.
B) That the tread is at least 1 mm deep.
C) Nothing, tyre pressures do not depend on load.
D) That they are inflated to the manufacturer's pressure for the load being carried.
Answer: D. Tyres must be correctly inflated to the manufacturer's specification for the load being carried. The legal minimum tread depth for cars is 1.6 mm, not 1 mm. (Highway Code Annex 6)
Practise this on the road: Find the tyre pressure label in your practice car and check what pressures it gives for a full load.
Q4. You are towing a trailer on a three-lane motorway with no lane closures. Which lane must you not use?
A) None, towing vehicles may use any lane.
B) The middle lane.
C) The right-hand lane.
D) The left-hand lane.
Answer: C. Vehicles towing trailers must not use the right-hand lane of a motorway with three or more lanes, except in prescribed circumstances. (Highway Code rule 265)
Practise this on the road: On a motorway lesson, point out which vehicles are not allowed in the right-hand lane of a three-lane motorway.
Q5. Where should heavy items be placed when loading a trailer?
A) On top of lighter items, so they are easy to reach.
B) Mainly over the axle, with a downward load on the tow ball.
C) It makes no difference to stability.
D) At the very back, to lift the tow ball.
Answer: B. Rule 98 says to distribute the weight so heavy items are mainly over the axle(s), with a downward load on the tow ball. (Highway Code rule 98)
Practise this on the road: Before a trip with luggage, practise packing heavy items low and secure so nothing can move when you brake.
Q6. You are carrying a 10-year-old passenger who is 1.30 metres tall. Who is legally responsible for making sure they use a suitable child restraint?
A) The driver.
B) The child.
C) The child's parent, even if they are not in the car.
D) Nobody, it is advisory only.
Answer: A. The driver must make sure children under 14 are wearing a seat belt or using an approved child restraint, and a child under 12 and under 1.35 metres generally needs a child restraint. (Highway Code rule 100)
Practise this on the road: Before driving with young passengers, check each child is using the right seat belt or child restraint.
Q7. Where must you never fit a rear-facing baby seat?
A) In the rear seat behind the driver.
B) In a seat protected by an active frontal airbag.
C) In a car with child locks.
D) In the rear middle seat.
Answer: B. You must not put a rear-facing baby seat in a seat protected by an active frontal airbag. (Highway Code rule 101)
Practise this on the road: Find out whether your practice car's front passenger airbag can be switched off and where the switch is.
Q8. You have loaded bags onto a roof rack for a trip. What MUST you make sure of before you drive?
A) That the load is covered with a sheet so it is dry.
B) That the load is secure and does not stick out dangerously.
C) That the heaviest bags are placed at the front of the rack.
D) That you drive no faster than 40 mph.
Answer: B. Rule 98 says you MUST secure your load and it MUST NOT stick out dangerously. A load that shifts or falls off can cause a crash. (Highway Code rule 98)
Practise this on the road: Before a drive with luggage, check every item is secure and nothing blocks your mirrors or view.
Q9. The trailer you want to tow is wider than your car and blocks your view behind. What should you fit?
A) Extra rear lights.
B) A reversing sensor only.
C) Suitable towing mirrors.
D) A larger number plate.
Answer: C. Rule 98 says towing mirrors must be used if your vehicle is narrower than the trailer or load, or the trailer or load obstructs your view to the rear. (Highway Code rule 98)
Practise this on the road: Adjust your mirrors before every drive and check you can see clearly behind and to both sides.
Q10. What is the purpose of a breakaway cable or safety chain when towing?
A) To stop the trailer bouncing on bumps.
B) To act as a secondary coupling if the main coupling fails.
C) To lock the trailer to the car when parked.
D) To power the trailer's lights.
Answer: B. Rule 98 says a trailer must be fitted with a secondary coupling device, such as a safety chain. It is there as a back-up if the main coupling fails. (Highway Code rule 98)
Practise this on the road: Discuss with your supervisor the checks you would need to make before towing, using rule 98 as a list.
Next steps
Head back to the theory test hub for every topic. Safety margins goes deeper on stopping distances, and vehicle handling covers how road surfaces and weather affect control. If you want to see how the motorway lane and speed signs look, visit our motorway signs guide.