Headlights and sidelights: choosing the right lights

Sidelights help indicate a vehicle's presence; dipped headlights also help you see the road. Daytime running lights are a different system and should not be treated as a substitute for headlights in darkness or seriously reduced visibility. Knowing which setting is active matters more than assuming that a lit dashboard means the car is correctly lit outside.

Start by learning the controls in the car you actually drive. A handbook, a stationary demonstration and a supervised lighting check are more useful than memorising where a switch was positioned in someone else's vehicle.

The basic Great Britain lighting rules

Highway Code rules 113–115 distinguish legal requirements from recommended practice:

• Sidelights and rear registration-plate lights must be lit between sunset and sunrise.
• Headlights must be used at night, apart from the stated exception for roads with lit street lighting; the Code nevertheless recommends dipped headlights in built-up areas at night.
• Headlights are required when visibility is seriously reduced.
• Lights must not be used in a way that dazzles other road users.

For these rules, night means the period from half an hour after sunset until half an hour before sunrise. Do not turn that definition into a reason to postpone using suitable lights when conditions already call for them.

Northern Ireland publishes its own lighting rules within its Highway Code. Consult those when driving there rather than treating this GB legal summary as a substitute.

Dipped beam and main beam have different jobs

Dipped beam is the normal headlight setting you should recognise first. Main beam provides a different beam pattern for suitable circumstances, but you must manage it so that it does not dazzle others. The car's handbook explains the control and dashboard indication.

Do not learn the control merely as “push the stalk”. Depending on the vehicle, a stalk movement may select main beam, flash the headlights or interact with an automatic system. Ask your instructor to show you the actual result and how to return to dipped beam.

Practise this while safely parked. Name the selected setting, identify the indicator and check that you can reverse the action without searching. That small exercise removes an unnecessary source of distraction when a change is needed on the road.

Daytime running lights are not your night-driving setup

The DfT's daytime-running-light guidance explains that these lamps are designed to make the vehicle more conspicuous during the day, not to illuminate the road at night. Their operation is not the same as switching on the vehicle's full night-time lighting arrangement.

Do not assume the rear lamps are on just because you can see bright lamps at the front. Confirm what your particular car does using its handbook and a safe external check. Different vehicles and settings can produce different results.

Imagine collecting a different car on a bright afternoon and returning after dusk. The correct preparation is to find the lighting controls before leaving, not discover on the return journey that the setting you recognised was only the daytime system.

Treat automatic lighting as a feature to understand

An automatic setting is not a reason to stop assessing visibility yourself. Find out how the system operates, how to select headlights manually and what the dashboard tells you. Do this before a journey in an unfamiliar car.

Use three separate questions:

• Which setting have I selected?
• Which lamps does that setting actually operate in this car?
• Are those lamps suitable for the conditions now?

These questions also help when learning with one car and practising privately in another. A familiar-looking symbol does not guarantee that every surrounding control behaves identically.

If a warning appears or a lamp does not work, investigate safely before relying on it. Do not cover up a fault by choosing a brighter but inappropriate setting. Obtain suitable repair advice rather than improvising an electrical modification.

Poor visibility is not only a night-time problem

Highway Code rule 226 requires headlights when visibility is seriously reduced, generally when you cannot see beyond about 100 metres. Daylight alone therefore does not answer the lighting question.

For a learner, it helps to separate brightness from visibility. Ask what road information you can actually identify ahead and whether other road users can see your car. Avoid deciding solely from how bright the sky looks through the top of the windscreen.

Fog lights are separate controls with separate conditions for use, not an upgrade to leave on routinely. Learn where they are and how to switch them off again. A control that is easy to activate but difficult to identify afterwards is a practice task worth solving while stationary.

Check the result, not just the switch

The DVSA vehicle-safety questions include explaining how to check headlights and tail lights, operating rear fog lights, and changing from dipped to main beam. These are practical skills, not just answers to recite for an examiner.

With the car secured in an appropriate place, identify the switch and then confirm the exterior lamps work. Keep clear of moving traffic during any walk-around. Ask someone to help where appropriate rather than putting yourself behind or in front of a vehicle that is not safely secured.

Make lighting part of your normal preparation

After setting the driving position and adjusting your mirrors, include a quick check of the conditions and lighting setup. Before an evening lesson, discuss what will change between the start and finish rather than assuming the outward and return journeys need the same preparation.

Our Swansea learning guide uses an evening visit to Copr Bay as an example of planning the return as well as the arrival. Wherever your destination is, include the expected lighting conditions in that return plan; the fact that you arrived in daylight does not prepare the car for the journey home.

Use our driving courses to plan tuition around your experience, or contact Learn and Drive if you want help with night-driving preparation or unfamiliar controls. A useful goal is to explain which lights you need, select them without distraction and confirm that the car is both visible and giving you the view you need.