The most difficult theory test questions

Because so many people use our site to test their knowledge, we have a rich history of data on each test question (over 1,000 multiple choice questions from the DVSA revision question bank). This means we can see which questions people struggle with and which ones they find easy.

We've analysed the data from the last 100,000 quiz attempts on this site. We've then looked at the percentage of people that got each question correct. This has revealed the most difficult theory test questions.

Based on this research, we've collated two of the most difficult questions from each of the 14 practice tests in our highway code study series to produce this very difficult mock theory test.

Difficulty level
Warning - maximum difficulty!
Most people cannot score more than 69% on these questions. Can you?

Mock theory tests

Mock theory test 1

With hints

Mock theory test 2

Optional hints

Mock theory test 3

Most difficult

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Step 1 of 29

You are turning right onto a dual carriageway. What should you do before emerging?*

Stop and apply the handbrake and then select a low gear

Position your vehicle well to the left of the side road

Check that the central reservation is wide enough for your vehicle

Make sure you leave enough room for a vehicle behind

Show hint

Before emerging right onto a dual carriageway make sure that the central reserve is deep enough to protect your vehicle. If it’s not, you should treat it as one road and check that it’s clear in both directions before pulling out. Neglecting to do this could place part or all of your vehicle in the path of approaching traffic and cause a collision.

In which of these situations should you avoid overtaking?*

Just after a bend

In a one-way street

On a 30 mph road

Approaching a dip in the road

Show hint

As you begin to think about overtaking, ask yourself if it’s really necessary. If you can’t see well ahead stay back and wait for a safer place to pull out.

At a puffin crossing, which colour follows the green signal?*

Steady red

Flashing amber

Steady amber

Flashing green

Show hint

Puffin crossings have infra-red sensors which detect when pedestrians are crossing and hold the red traffic signal until the crossing is clear. The use of a sensor means there is no flashing amber phase as there is with a pelican crossing.

You are waiting in a traffic queue at night. To avoid dazzling following drivers you should*

apply the handbrake only

apply the footbrake only

switch off your headlights

use both the handbrake and footbrake

Show hint

You should consider drivers behind as brake lights can dazzle. However, if you are driving in fog it’s safer to keep your foot on the footbrake. In this case it will give the vehicle behind extra warning of your presence.

What percentage of all emissions does road transport account for?*

10%

20%

30%

40%

Show hint

Transport is an essential part of modern life but it does have environmental effects. In heavily populated areas traffic is the biggest source of air pollution. Eco-safe driving and riding will reduce emissions and can make a surprising difference to local air quality.

Unbalanced wheels on a car may cause*

the steering to pull to one side

the steering to vibrate

the brakes to fail

the tyres to deflate

Show hint

If your wheels are out of balance it will cause the steering to vibrate at certain speeds. It is not a fault that will rectify itself. You will have to take your vehicle to a garage or tyre fitting firm as this is specialist work.

You are travelling at 50 mph on a good, dry road. What is your typical overall stopping distance?*

36 metres (118 feet)

53 metres (175 feet)

75 metres (245 feet)

96 metres (315 feet)

Show hint

Even in good conditions it will usually take you further than you think to stop. Don’t just learn the figures, make sure you understand how far the distance is.

You are on a good, dry, road surface. Your brakes and tyres are good. What is the typical overall stopping distance at 40 mph?*

23 metres (75 feet)

36 metres (118 feet)

53 metres (175 feet)

96 metres (315 feet)

Show hint

Stopping distances are affected by a number of variable factors. These include the type, model and condition of your vehicle, road and weather conditions, and your reaction time. Look well ahead for hazards and leave enough space between you and the vehicle in front. This should allow you to pull up safely if you have to, without braking sharply.

You are driving towards this level crossing. What would be the first warning of an approaching train?*

Both half barriers down

A steady amber light

One half barrier down

Twin flashing red lights

Show hint

The steady amber light will be followed by twin flashing red lights that mean you must stop. An alarm will also sound to alert you to the fact that a train is approaching.

What does this signal from a police officer mean to oncoming traffic?*

Go ahead

Stop

Turn left

Turn right

Show hint

Police officers may need to direct traffic, for example, at a junction where the traffic lights have broken down. Check your copy of The Highway Code for the signals that they use.

What does this sign mean?*

Contraflow pedal cycle lane

With-flow pedal cycle lane

Pedal cycles and buses only

No pedal cycles or buses

Show hint

The picture of a cycle will also usually be painted on the road, sometimes with a different coloured surface. Leave these clear for cyclists and don’t pass too closely when you overtake.

You see a pedestrian with a dog. The dog has a yellow or burgundy coat. This especially warns you that the pedestrian is*

elderly

dog training

colour blind

deaf

Show hint

Take extra care as the pedestrian may not be aware of vehicles approaching.

You are waiting to emerge left from a minor road. A large vehicle is approaching from the right. You have time to turn, but you should wait. Why?*

The large vehicle can easily hide an overtaking vehicle

The large vehicle can turn suddenly

The large vehicle is difficult to steer in a straight line

The large vehicle can easily hide vehicles from the left

Show hint

Large vehicles can hide other vehicles that are overtaking, especially motorcycles which may be filtering past queuing traffic. You need to be aware of the possibility of hidden vehicles and not assume that it is safe to emerge.

Which of these is LEAST likely to be affected by crosswinds?*

Cyclists

Motorcyclists

High-sided vehicles

Cars

Show hint

Although cars are the least likely to be affected, crosswinds can take anyone by surprise. This is most likely to happen, after overtaking a large vehicle, when passing gaps between hedges or buildings, and on exposed sections of road.

When may you overtake another vehicle on the left?*

When you’re in a one-way street

When approaching a motorway slip road where you’ll be turning off

When the vehicle in front is signalling to turn left

When a slower vehicle is travelling in the right-hand lane of a dual carriageway

Show hint

You may pass slower traffic on their left while driving along a one-way street. Be aware of drivers who may need to change lanes and not expect faster traffic passing on their left.

You are braking on a wet road. Your vehicle begins to skid. It does not have anti-lock brakes. What is the FIRST thing you should do?*

Quickly pull up the handbrake

Release the footbrake

Push harder on the brake pedal

Gently use the accelerator

Show hint

If the skid has been caused by braking too hard for the conditions, release the brake. You may then need to reapply and release the brake again. You may need to do this a number of times. This will allow the wheels to turn and so limit the skid. Skids are much easier to get into than they are to get out of. Prevention is better than cure. Stay alert to the road and weather conditions. Drive so that you can stop within the distance you can see to be clear.

On a motorway what is used to reduce traffic bunching?*

Variable speed limits

Contraflow systems

National speed limits

Lane closures

Show hint

Congestion can be reduced by keeping traffic at a constant speed. At busy times maximum speed limits are displayed on overhead gantries. These can be varied quickly depending on the amount of traffic. By keeping to a constant speed on busy sections of motorway overall journey times are normally improved.

You are on a motorway. There are red flashing lights above every lane. You must*

pull onto the hard shoulder

slow down and watch for further signals

leave at the next exit

stop and wait

Show hint

Red flashing lights above every lane mean you must not go on any further. You’ll also see a red cross illuminated. Stop and wait. Don’t
• change lanes
• continue
• pull onto the hard shoulder (unless in an emergency).

You are driving at night with full beam headlights on. A vehicle is overtaking you. You should dip your lights*

some time after the vehicle has passed you

before the vehicle starts to pass you

only if the other driver dips their headlights

as soon as the vehicle passes you

Show hint

On full beam your lights could dazzle the driver in front. Make sure that your light beam falls short of the vehicle in front.

You can park on the right-hand side of a road at night*

in a one-way street

with your sidelights on

more than 10 metres (32 feet) from a junction

under a lamp-post

Show hint

Red rear reflectors show up when headlights shine on them. These are useful when you are parked at night but will only reflect if you park in the same direction as the traffic flow. Normally you should park on the left, but if you’re in a one-way street you may also park on the right-hand side.

What does this sign mean?*

Waiting restrictions apply

Waiting permitted

National speed limit applies

Clearway (no stopping)

Show hint

There will be a plate or additional sign to tell you when the restrictions apply.

What does this sign mean?*

End of restricted speed area

End of restricted parking area

End of clearway

End of cycle route

Show hint

Even though you have left the restricted area, make sure that you park where you won’t endanger other road users or cause an obstruction.

For how long is a Statutory Off Road Notification (SORN) valid?*

Until the vehicle is taxed, sold or scrapped.

Until the vehicle is insured and MOT’d.

Until the vehicle is repaired or modified.

Until the vehicle is used on the road

Show hint

A SORN declaration allows you to keep a vehicle off road and untaxed. SORN will end when the vehicle is taxed, sold or scrapped.

Your vehicle needs a current MOT certificate. Until you have one you will NOT be able to*

Renew your driving licence

Change your insurance company

Renew your vehicle excise licence

Notify a change of address

Show hint

If your vehicle is required to have an MOT certificate you will need to make sure this is current before you are able to renew your vehicle excise licence (road tax). You can renew online, by phone or at certain post offices.

You arrive at an incident. There has been an engine fire and someone’s hands and arms have been burnt. You should NOT*

douse the burn thoroughly with clean cool non-toxic liquid

lay the casualty down on the ground

remove anything sticking to the burn

reassure them confidently and repeatedly

Show hint

This could cause further damage and infection to the wound. Your first priority is to cool the burn with a clean, cool, non- toxic liquid, preferably water. Don’t forget the casualty may be in shock.

At an incident it is important to look after any casualties. When the area is safe, you should*

get them out of the vehicle

give them a drink

give them something to eat

keep them in the vehicle

Show hint

When the area is safe and there’s no danger from other traffic or fire it’s better not to move casualties. Moving them may cause further injury.

You're towing a small trailer on a busy three-lane motorway. All the lanes are open. You must*

not exceed 50 mph

not overtake

have a stabiliser fitted

use only the left and centre lanes

Show hint

The motorway regulations for towing a trailer state that you MUST NOT
• use the right-hand lane of a three-lane motorway, unless directed to do so (for example at roadworks or due to a lane closure)
• exceed 60 mph.

A trailer must stay securely hitched up to the towing vehicle. What additional safety device can be fitted to the trailer braking system?*

Stabiliser

Jockey wheel

Corner steadies

Breakaway cable

Show hint

In the event of a towbar failure the cable activates the trailer brakes, then snaps. This allows the towing vehicle to get free of the trailer and out of danger.

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If you can handle this then well done. If you struggled then don't despair, try a more general mock theory test.