Mandatory lights
Every car carries, among others, dipped and main beam, reversing, brake, position and number-plate lights, and indicators.
- Vehicles wider than 2.10 m add outline marker lights.
Source: RGV art. 16
Tema 18: vehicle lighting in the DGT exam
Four rules separate correct light use: what lights to carry, when to switch them on, how not to dazzle, and what to do if you stop at night.
Reviewed on 11 October 2026 · sources: BOE and DGT
This tema asks which lights you must carry, when to switch them on, how not to dazzle, and what to do if you stop at night.
- Every car carries, among others, dipped and main beam (luz de cruce), reversing, brake, front and rear position lights, indicators and a number-plate light. Above 2.10 m wide, outline marker lights are added.
- Use lights between sunset and sunrise, and by day if fog, heavy rain, snow or smoke significantly reduce visibility.
- Switch to dipped beam as soon as you might dazzle another road user, and do not go back to main beam until you have passed them.
- A vehicle immobilised on the carriageway (calzada) or shoulder (arcén) between sunset and sunrise must have its position lights on.
Watch out: leaving the rear fog light on in good visibility dazzles the driver behind.
In DrivingLingo: review the traffic signs, tema 35 on night driving and poor visibility, tema 36 on rain, fog, snow and tunnels and the .
Source: RGV art. 16; RGC arts. 102, 105, 106.
Key rules of topic 18
When to switch lights on
You use lights between sunset and sunrise, and by day when fog, heavy rain, snow or smoke significantly reduce visibility.
- Driving without lights in these conditions counts as a serious offence.
Source: RGC art. 106, apdos. 1 y 3
Front and rear fog lights
The rear fog light is switched on only when conditions are especially unfavourable, such as thick fog or very heavy rain.
- The front fog light is less strict: it may be used alone or with dipped beam in any reduced visibility, or on narrow, winding roads up to 6.5 m wide.
Source: RGC art. 106, apdo. 2
Avoiding dazzle
You must switch to dipped beam as soon as you might dazzle another road user, and not go back to main beam until you have passed them.
- The same care applies if you might dazzle, via their mirror, someone ahead of you going the same way.
- If you are dazzled, reduce speed, even to a full stop, so you do not hit anyone.
Source: RGC art. 102
Stopped at night
A vehicle immobilised on the carriageway or shoulder between sunset and sunrise must have its position lights on.
- On a poorly-lit travesía, parked in line, you may replace them with the two position lights on the roadway side.
- On an ordinary urban street they are not needed if the lighting lets others see you from far enough away.
Source: RGC art. 105
Learn the rule, then practise it
Study topic 18 step by step: the rule, its citation and exam-style questions.
Start in the app