Modern cars have a bewildering array of lights and it is easy to become confused about what to use and when, especially when so many models now have automated headlamps which take care of most of the decision making for us.
However, even the most sophisticated car can’t yet decide when to switch on your lamps to drive in fog.
Vehicles are fitted with rear fog light buttons to enhance visibility and improve safety in adverse weather conditions, such as heavy rain, fog, or snow. Rear fog lights emit a bright, low-mounted red light that is designed to cut through dense fog and make the vehicle more visible to drivers approaching from behind. This helps to reduce the risk of rear-end collisions as other drivers can more easily see the vehicle ahead in low-visibility conditions. Rear fog lights are typically used in combination with front fog lights to create a more prominent lighting pattern that increases overall visibility for the vehicle in foggy conditions. It's important to note that rear fog lights should be used only when necessary and should be turned off once visibility improves to avoid dazzling or confusing other drivers.
Fog lights are brighter and have a different beam spread than conventional head and tail lamps and are designed to help you see and be seen in poor visibility. That doesn’t just mean fog; it can also relate to snow and heavy rain.
At the front, the lamps are mounted low and the beam is wider to try and illuminate as much as possible without the beam bouncing from the fog and dazzling the driver.
If it was built after 1st April 1980, your car will have at least one fog lamp button on the dashboard as it is a legal requirement. This law was brought in to prevent accidents where following drivers have not been able to see other vehicles in poor conditions. Many vehicles will also have front fog lights fitted, although these are not compulsory and are primarily designed to help the driver see more of the road.
They are different to the daytime running lights which are fitted to modern cars and can only be used when the sidelights or headlamps are turned on.
You will be able to find the switch (or switches, if you have front fog lights too) either in a prominent place on the dashboard or on the same stalk behind the steering wheel as the other lighting controls – usually on the left side. When they are illuminated, there will be a warning light on the instrument panel.
It’s best to know where they are before you set off on a journey so you’re not distracted while driving, especially as the poor conditions will require all of your attention. The experts at Eden will be happy to show you how to use the controls when you pick up your new car.
According to the Highway Code (rule 226), fog lights should only be used when visibility drops below 100 metres (328 feet) which is roughly the length of 20 cars or a football pitch. You should turn them off as soon as the conditions improve, as they can be distracting and dazzling to other road users and will make your brake lights less discernible.
Besides being inconsiderate to other drivers, you can also be fined £30 for misusing your fog lights.
Yes, the rear fog lamp or lamps fitted to any car used after 1st April 1980 must work, and show a warning light on the dashboard when in use. If front fog lights are fitted to vehicles first used after March 2018, they must work too. Fog lamps must be white at the front and red at the rear.
Some modern headlights use sophisticated LED beams which can adapt to different conditions, including fog and poor visibility. These make conventional front foglights obsolete.