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BRoad safety ·4 / 12· ~8 min

Vehicle operation and maintenance

Prefer to practise the DGT theory test in English? Our English hub covers every topic and permit in one place.

Step 1. The big picture

A person holds an oil dipstick and a cloth beside a green car parked off the road with its bonnet open.
Checking the engine oil level

In one sentence…

Road safety combines prevention, occupant protection and the correct reaction to an emergency. The theory exam usually mixes active safety, passive safety and the PAS response within the same question, so always study cause, consequence and safe conduct together.

Step 2. The syllabus

2.1Active safety

Active safety helps to avoid the accident: brakes, steering, tyres, suspension, lighting and electronic aids all work before the impact.

  • These elements only work well if the driver maintains the vehicle and adapts their driving. A poor tyre or badly used light reduces your margin before danger strikes.
  • In the exam, a question may mention rain, a bend or braking to check whether you know active safety also depends on grip and anticipation.
  • Don't confuse electronic aids with permission to take risks. Their role is to support, not to compensate for inadequate speed or insufficient distance.

2.2Passive safety

Passive safety reduces injuries once the accident can no longer be avoided: seatbelt, headrest, airbags, the vehicle's structure and child restraint systems.

  • A badly adjusted headrest or a loose seatbelt can turn an apparently minor rear-end collision into a serious injury for any occupant.
  • The airbag does not replace the seatbelt. In questions about occupants, the correct answer usually requires both systems to work together.
  • Passive protection starts before you set off: seat, backrest, headrest, seatbelts and loose objects must all be under control so as not to increase harm.

2.3Seatbelt and posture

The seatbelt must be used whenever the vehicle is fitted with one, and it must be well adjusted, without slack or twists.

  • Correct posture lets you control the pedals, steering wheel, mirrors and controls without stretching. It also helps the seatbelt, headrest and airbag protect you as they should.
  • Don't fit clips, cushions or thick clothing that leave dangerous slack. In an impact, these details change how effective the system really is.
  • In tests, be wary of answers that accept wearing the seatbelt any old way for short trips, low speed or rear seats.

2.4Child restraint systems

Minors must travel in the child restraint system suited to their height, weight and type approval, following the seating positions and conditions set out in law.

  • The driver must make sure the system is installed and used correctly. It's not enough for the minor to be sitting in just any device.
  • The question may not ask for a figure: it may ask for the principle. A minor travels protected when the system matches their characteristics and is fitted correctly.
  • If in doubt between comfort and safety, choose safety. The rule aims to reduce injuries even if the trip is short or the minor complains.

2.5The PAS response

The safe sequence follows the PAS principle: protect the area, alert the emergency services and assist without worsening injuries or creating another danger.

  • Protecting means preventing further collisions before helping. Park safely, make yourself visible and assess the traffic so you don't become another victim.
  • Alerting requires clearly conveying where you are and what has happened. Don't improvise rescue manoeuvres that could worsen injuries unless they are essential.
  • Assisting doesn't always mean moving the injured person. In the exam, the cautious answer is usually to stay with them, avoid additional risks and wait for qualified help when appropriate.

2.6Breakdown and immobilisation

Since 1 January 2026, the connected V16 light is the official reference for pre-signalling an immobilised vehicle for those vehicles required to carry the device.

  • Before helping, avoid becoming a new victim: park safely, use visibility items and don't step onto the carriageway without controlling the risk.
  • In a breakdown, the priority is not to get the vehicle moving quickly again, but to reduce your own exposure and that of other road users.
  • Questions often pit haste against safety. Always choose the orderly response: protect first, alert next, and only assist if you don't worsen the danger.

2.7Exam preparation

Classify each element as active or passive and say what risk it reduces. This method stops you learning lists without understanding why they appear together in a question.

  • Practise cases: rear-end collision, rollover, rain, a night-time breakdown and a child occupant. In each one, decide which system prevents and which protects.
  • The B theory test is 30 questions with a maximum of 3 errors in 30 minutes. It pays to master these topics because they tend to appear with very everyday scenarios.
  • When an answer plays down a measure because the trip is short, it's usually suspect. Road safety applies whenever you're driving.

Step 3. Key points

If you only have a minute before the exam, revise this.

  1. 1.Tell active and passive safety apart with real examples.
  2. 2.Adjust the seat, seatbelt and headrest before setting off.
  3. 3.Use the seatbelt, airbag and child restraint systems correctly.
  4. 4.Apply PAS without putting yourself in danger or worsening injuries.
  5. 5.Know the official reference for the connected V16 light in 2026.
  6. 6.Link basic maintenance to the effectiveness of brakes, lights and tyres.
  7. 7.Be wary of answers that justify skipping measures on short trips.

Step 4. Exam traps

Mistakes the DGT uses again and again on this topic.

  • Thinking that wearing the seatbelt any old way is enough.
  • Confusing an active safety element with a passive one.
  • Getting out of the vehicle without assessing the road's risk during a breakdown or accident.
  • Believing the airbag replaces the seatbelt.
  • Moving an injured person unnecessarily and without assessing whether you might worsen their injuries.
  • Forgetting that the connected V16 is the official reference from 1 January 2026.

Step 5. Quick check

Four real exam questions on what you have just read.

Question 1/4

Can a driver reduce the probability of accidents caused by the "vehicle factor"?

Practise more vehicle operation and maintenance questions

Step 6. Frequently asked questions about vehicle operation and maintenance

What is the engine oil dipstick used for?
To check the oil level. To check oil level, not its pressure or temperature. On engines with a dipstick, follow the manual’s procedure: it is normally read between its marks after wiping and fully reinserting it. Use a level surface and observe the manufacturer’s engine-stop, temperature and waiting-time conditions. Do not assume a universal waiting time or temperature, or add oil above maximum.See full question
Your car is immobilised by a breakdown inside a tunnel. Of these actions, which should you take immediately to warn vehicles approaching from behind?
Switch on the hazard warning lights. Switch on the hazard lights and keep the position lights on. Switch off the engine once immobilised. If it can continue safely, leave the tunnel or reach an emergency area; otherwise use that area if possible or stop close to the right edge. Request help through an SOS post if available and follow instructions. If leaving the vehicle, use the area excluded from traffic, where available, to reach a refuge or exit. Do not confuse this breakdown with stopping in congestion.See full question
Why is it advisable to change the lubricating oil periodically?
Because oil in good condition helps protect the engine and reduce wear. Oil deteriorates and accumulates contaminants with use and time, reducing its ability to protect the engine. Replacing it with the manufacturer’s specified oil and at the specified intervals helps reduce wear. Checking and topping up the level does not replace periodic changes; changing it does not guarantee prevention of every breakdown.See full question
To achieve efficient driving, you must drive...
At a steady speed when safe, avoiding unnecessary acceleration and braking. When conditions permit, maintain a steady speed adapted to the limits, anticipate changes in traffic and avoid unnecessary acceleration and braking. Use a gear suitable for the engine and situation. Safety takes precedence over economy: brake or stop, including decisively in an emergency, whenever necessary.See full question
What is the function of an engine's cooling system?
Remove some of the heat produced in an engine. The main function of the cooling system is to remove the heat produced during combustion until a level is reached at which the engine achieves maximum performance without impairing the mechanical strength of the components or the lubricating properties of the oils.See full question
See all vehicle operation and maintenance questions

Official sources