Lights are one of the densest topics on the Gibraltar paper. Around a dozen questions turn on when to switch something on and, more often, when to switch it off. The examiner is testing one idea throughout: you must be seen without blinding anyone else.
Front fog lights
They may be used only if visibility is seriously reduced, which in practice means less than 100 metres. That is the only condition. Not dusk, not drizzle, not because they look good.
The paper asks twice about turning them off, which tells you how much it matters. Once the fog clears you switch them off as long as visibility remains good, and while driving in fog you should remember to switch them off as visibility improves. Fog lifts and falls; keep checking.
Rear fog lights are the trap
Rear fog lights are as bright as brake lights, which is exactly the problem. Left on when they are not needed they:
- Dazzle the driver behind you
- Make your brake lights less clear, because yours are already lit
- Are breaking the law
That last one surprises people. Using fog lights in good visibility is an offence, not just bad manners. Coming out of fog, you must switch off all your fog lights.
On a clear dry night, leaving them on will make other drivers think you are braking and dazzle following drivers.
Rain and spray
Rain is treated differently from fog, and the distinction earns marks.
On a wet motorway with surface spray, use dipped headlights. In heavy traffic on a wet road where spray makes it hard to be seen, use dipped headlights, and rear fog lights only if visibility is less than 100 metres.
So dipped headlights are almost always the answer. Rear fog lights are for that one specific threshold.
Before you set off into fog
The paper asks what two things matter most before a journey in fog. The answer is to have a warning triangle in the vehicle and to check that your lights are working.
The rule underneath all of it
Every one of these questions comes back to the same thing. Lights exist so you can see and be seen. The moment a light stops helping you be seen and starts stopping someone else seeing, it goes off.