Photo: Abdulvahap Demir / Pexels. Illustrative photograph.
Driver assistance systems (ADAS) such as automatic emergency braking, lane assist and parking sensors can warn you or step in, but they do not drive the car and they do not see everything. In Great Britain the Highway Code is clear: you must have proper control of your vehicle at all times and you are still responsible when a system is in use. This guide explains the common systems, their limits, which ones you can use on the GB driving test, and how to learn a new car’s technology safely.
Key facts
- Highway Code rule 150: do not rely on driver assistance systems such as motorway assist, lane departure warnings or remote control parking. They are there to assist, but you should not reduce your concentration.
- You are responsible: rule 150 says you are still responsible for the vehicle if you use a driver assistance system, and you must have full control over these systems at all times.
- GB test, allowed: electronic parking brake, hill-start assist, cruise control, speed limiters, parking sensors and cameras, lane assist, blind spot monitoring and traffic sign recognition.
- GB test, not allowed to use: self-parking, Tesla autopilot and your own sat nav.
- DVSA’s Ready to Pass skills list includes understanding any driver assistance technology fitted to your vehicle.
Common systems and what they cannot do
Names differ between manufacturers, and two systems with similar names can behave differently. Your car’s handbook is the authority on yours.
| System | What it generally does | Limits to remember |
|---|---|---|
| Automatic emergency braking (AEB) | Warns and may brake if it detects a likely collision ahead | May not detect every vehicle, pedestrian or cyclist, or work in all weather and speeds. It is a last resort, not a following-distance tool. |
| Lane departure warning and lane keeping assist | Warns or steers gently if you drift out of your lane | Needs visible lane markings; faded lines, road works and snow can confuse it. It does not check whether a lane change is safe. |
| Blind spot monitoring | Lights a warning if a vehicle is beside or behind you | Does not replace a look over your shoulder. Fast-approaching or small road users may be missed. |
| Parking sensors and cameras | Beep or show a picture near obstacles | Low kerbs, thin posts and small children can be missed. Dirt on a camera hides things. |
| Cruise control and adaptive cruise | Holds a set speed; adaptive versions also keep a gap to the vehicle ahead | You still choose a safe speed for the conditions. Adaptive systems may react late to stopped traffic or vehicles cutting in. |
| Speed limiters and traffic sign recognition | Shows the speed limit or stops you exceeding a set speed | Can misread signs or miss temporary limits. The sign on the road is what counts. |
| Hill-start assist and auto hold | Holds the brakes briefly or while stopped | May only hold for a short time. See hill starts explained. |
| Self-parking and remote parking | Steers (and sometimes drives) into a space | Not allowed during the GB test. Rule 150 says you are still responsible if you use a remote parking app or device. |
Driver assistance and the GB driving test
GOV.UK lists what you can and cannot use in your own car on the test.
| You can use a car with | You cannot use during the test |
|---|---|
| Electronic parking brake, hill-start assist, cruise control, speed limiters, parking sensors and cameras, lane assist, blind spot monitoring, traffic sign recognition | Self-parking, Tesla autopilot, your own sat nav (the examiner sets up a sat nav for you) |
Being allowed is not the same as being enough. Sensors and cameras can help during a parking manoeuvre, but you still need full observation all around the car. A blind spot light is not a blind spot check. If you rely on technology instead of looking, you can still pick up faults for observation. See driving test manoeuvres and driving test faults.
The test car must also not have any warning lights showing safety issues. A driver assistance fault light can be one of them. See dashboard warning lights.
How to learn a car’s systems safely
- Read the handbook first. Find out what each system does, when it switches on, and its dashboard symbols.
- Learn the states while parked. Many displays show a system as off, available, active or unavailable using different colours or symbols.
- Try it somewhere quiet with your instructor, such as cruise control on a quiet main road, not for the first time in heavy traffic.
- Know how to switch it off and how to override it, for example by braking or steering.
- Keep your normal routines. Mirrors, blind spot checks and planning stay exactly the same.
- In a different car, start again. Ready to Pass asks learners to adapt quickly when driving a different vehicle. Do not assume a feature you used before is fitted or switched on.
When the system steps in
If the car beeps, brakes or steers during a lesson, treat it as feedback. Ask what you could have spotted earlier:
- A forward collision warning usually means the gap was too small or you saw the hazard late. Highway Code rule 126 says allow at least a two-second gap on high-speed roads, at least double on wet roads.
- A lane departure warning may mean distraction or tiredness.
- A parking sensor alarm may mean your observations were not good enough.
The system stepping in does not mean your original plan was safe. It means the plan needed help.
Distraction from screens
Rule 150 also warns about distraction from in-car systems such as sat navs, multimedia and screens. Do not be distracted by maps or screen information while driving; if necessary, find a safe place to stop. Set up the sat nav, music and driving modes before you move off. Rule 149 says you must not use a hand-held phone or similar device while driving. See mobile phones, sat navs and in-car technology.
Safety ratings and assistance technology
Euro NCAP includes active safety technology in its ratings for new cars, and sometimes publishes a second rating for cars fitted with an optional safety pack. If you are buying, check that the exact car has the equipment the rating assumed. See choosing your first car.
Ireland
The same principle applies: the driver is in control and responsible. Check the RSA’s current test vehicle requirements before your Irish test, rather than assuming the GB list applies. See your car for the Irish driving test.
Common questions
Can I use parking sensors on my driving test?
In GB, yes. GOV.UK lists parking sensors and cameras as allowed. You still need to look all around the car during manoeuvres.
Can I use cruise control on the test?
GOV.UK lists cruise control among the features a test car can have. Using it is not required, and you must still choose a safe speed.
If the car brakes automatically and avoids a crash, is it my fault?
In law you are still responsible for the vehicle. Treat any intervention as a sign to leave more space and look further ahead.
Why does my car keep steering me back in the lane?
That is lane keeping assist. It reacts to lane markings, not to hazards, and it can usually be switched off. Ask your instructor whether to use it while learning.
Does adaptive cruise or lane assist make the car self-driving?
No. They are driver assistance systems: they help, but you are driving. The Highway Code says the driver remains responsible when a driver assistance system such as motorway assist is in use.
Does traffic sign recognition mean I can ignore speed limit signs?
No. The system can be wrong. You must obey the limit shown on the road. See UK speed limits.
Related: learning to drive an automatic, safety and your vehicle. Guides: learning to drive in Great Britain and learning to drive in Ireland.
Sources
- Department for Transport, “The Highway Code: General rules, techniques and advice for all drivers and riders (103 to 158)” (gov.uk)
- GOV.UK, “Driving test: cars, using your own car” (gov.uk)
- GOV.UK, “Driving test: cars, what happens during the test” (gov.uk)
- DVSA, “Control and positioning” (readytopass.campaign.gov.uk)
- Euro NCAP, “The ratings explained” (euroncap.com)