Lights – Driver intervention needed

Posted on September 29th, 2017 by Rob Marshall


As we are now well into the season of mists, I wish that some drivers could be told not to rely on automatic lights. I think that this is one reason why I am starting to see drivers on the early morning/school run commute, particularly, not realising that they are putting their lives (and those of others) at risk by not having their correct lights working. One reason, I think, is down to a belief that the car will select the most appropriate light setting for them for every condition. This is not the case. Alternatively, some modern instrument panels are illuminated, even when the exterior lighting is extinguished, a factor that also needs realising.

Daytime running lights

GEM has voiced this issue before but it is pertinent to repeat the advice. Daytime running lights (DRLs) became mandatory on all new car models from 2011. They are designed to help other road users see the car in daytime conditions. In low light, or foggy conditions, they are inadequate. Additionally, most cars have DRLs fitted to the front only, leaving the rear of the car unlit, which is most unwise in poor visibility. The only solution is to use dipped headlamps.

Dipped headlights

Many modern cars select dipped beam automatically, when a sensor (mounted on either the fascia, or behind the door mirror) detects low light conditions. Unfortunately, most drivers seem to rely completely on this feature, which is not as smart as they may think. For example, they will not switch-on the dipped beam lamps in bright but foggy conditions. Therefore, it is worth consulting your handbook’s advice on overriding the ‘auto’ setting, when confronted with these conditions. On some models, however, the light sensitivity can be altered.

Fog lights

The auto-light sensors do not control the fog lamps. Therefore, you will have to switch these on yourself, when you think that other motorists might not spot you. Yet, do not forget to switch them off again, when visibility improves, so you neither dazzle other road users, nor break the law. The front fog lights tend to be indicated as active by a green dashboard symbol. Active rear fog lamp(s) feature an orange symbol – see picture.