Using Your Lights on Your Driving Test in 2026: Headlights, Fog Lights and Hazards Explained

Lights are one of those parts of driving that feel trivial until an examiner is sitting beside you. Most learners can find the switch. Far fewer can explain, under pressure, when dipped beam becomes necessary, why rear fog lights are usually the wrong choice, or what hazard warning lights are actually for.

Lighting comes up on the practical test in three different ways: in the show me tell me questions, in your practical use of lights while driving, and occasionally in how you respond to another driver’s lights. This guide covers all three, in plain terms.

The Lights on a Modern Car and What Each One Does

When You Must Use Dipped Headlights

The Highway Code requires you to use headlights when visibility is seriously reduced, and at night. In practice, on a test, dipped beam is the right answer far more often than learners expect:

• From sunset to sunrise, always.
• In heavy rain, sleet, snow or spray.
• In dull, overcast daytime conditions where you would struggle to be seen.
• Through tunnels and long underpasses, even in daylight.
• At dawn and dusk, when the light is changing quickly.

A common trap involves daytime running lights. Because the front of the car is lit, drivers assume they are visible. In many cars the rear lights stay off, leaving you almost invisible from behind in heavy spray. If it is raining hard enough for wipers on continuous, put dipped headlights on.

Main Beam: The Etiquette Examiners Watch For

If your test route includes an unlit rural road after dark — more common on winter afternoon slots than you might think — main beam becomes relevant. The rules are straightforward:

• Use it on unlit roads when there is no oncoming traffic and no vehicle close in front.
• Dip as soon as you see an approaching vehicle, and dip when following another car.
• Dip for pedestrians, cyclists and horse riders too, not just cars.
• If you are dazzled by an oncoming driver, slow down and, if necessary, stop. Do not retaliate by flashing your own main beam.

Examiners are not testing your reflexes here. They are testing your judgement and your consideration for other road users, which is exactly what the DL25 marking sheet is designed to capture.

Fog Lights: The Most Commonly Misused Lights on the Road

Rear fog lights are dramatically brighter than normal rear lights. In clear conditions they dazzle the driver behind and mask your brake lights — which is genuinely dangerous, not merely annoying. The rule is simple: use them only when visibility is seriously reduced, which the Highway Code takes to mean roughly less than 100 metres, and switch them off as soon as it improves.

Two practical points for test day. First, know where the switch is and how to tell whether they are on — there is a warning light on the dashboard, usually amber for front fogs and amber or orange for rear. Second, if you switch them on because of fog, remember to switch them off when you emerge from it. Leaving them running is a fault and, on a public road, an offence.

Hazard Warning Lights: What They Are Actually For

Hazard lights have a narrow, specific purpose. You may use them:

• When your vehicle is stationary and causing a temporary obstruction — for example, if you break down.
• Briefly, while moving on a motorway or unrestricted dual carriageway, to warn drivers behind of a hazard or sudden queue ahead.

They are not for parking on double yellow lines, not for “just popping in for two minutes”, and not for saying thank you. On a test, the situation most likely to arise is if you are asked to pull up and the examiner considers you an obstruction — but even then, follow the examiner’s instruction rather than reaching for the switch on instinct.

Lights in the Show Me Tell Me Questions

Lighting appears regularly in the vehicle safety questions at the start of the test:

• Tell me how you would check the headlights and tail lights are working. Operate the switch, walk around the vehicle, or check reflections in a window or wall. You do not need to leave the car during the answer.
• Show me how you would switch on the dipped headlights. Operate the control and identify the dashboard indicator.
• Show me how you would set the rear fog lights and explain when you would use them. Switch them on and state that they are for visibility below roughly 100 metres.
• Show me how you would check the direction indicators are working. Operate the hazard switch or indicators and walk around the vehicle.

These are worth rehearsing out loud, in the car, until they are automatic. Getting a show me tell me question wrong is only a single driving fault, but fumbling one in the first two minutes rattles some candidates for the rest of the test.

The Faults That Cost Marks

1. Driving in poor visibility on sidelights or DRLs alone. The most common lighting fault by a distance.
2. Leaving rear fog lights on after the fog clears. Dazzles the driver behind and masks your brakes.
3. Failing to dip main beam for oncoming traffic. Marked as inconsiderate to other road users.
4. Not switching lights on in a tunnel. Many candidates forget entirely.
5. Using hazard lights while parked illegally. A misunderstanding that follows drivers well beyond the test.
6. Fumbling the light switch while moving. Practise finding it by touch so your eyes stay on the road.

How Exam Routes App Can Help

Lighting decisions depend on where you are: an unlit lane, a lit dual carriageway, a tunnel, a busy town centre in the rain. The Exam Routes App gives you real driving test routes with turn-by-turn navigation so you can practise those decisions on the actual roads your examiner may use.

If your test is booked for a winter afternoon, drive your local routes at the same time of day. Ten minutes of practice on a dusk route teaches more about lighting judgement than an hour of reading.

Frequently Asked Questions