Driving in fog: base your speed on what you can see

When driving in fog, reduce speed to suit the view, use appropriate lights and leave enough room to stop within the distance you can see clearly. Do not follow another vehicle's rear lights as though they guarantee a safe route. The Highway Code's fog guidance makes visibility and space central to the decision.

For learners, there is no benefit in treating dense fog as a confidence challenge. Preparation includes deciding whether to travel at all, discussing conditions with your instructor and knowing how to manage the controls before the view deteriorates.

Consider postponing before committing to the journey

National Highways advises checking the forecast and considering delaying a journey if fog is expected. Plan the route and suitable stopping opportunities, and make sure the car and its lighting controls are familiar.

If you have a lesson booked, contact the instructor rather than assuming it must go ahead unchanged. The decision should reflect the conditions and your stage of learning. Rescheduling or changing the lesson plan can be more useful than placing you in a situation where all your attention is consumed by anxiety.

For private practice, agree the destination and an alternative before leaving. Make sure the supervisor is comfortable with the plan. Do not begin with the assumption that you must complete the original route simply because time has been set aside for practice.

Check route-specific information as well as the forecast. Our Inverness guide uses the A9 Kessock Bridge to explain why current travel advice matters even on a familiar journey. A general weather report does not establish the present condition of every part of your route.

Know your dipped-headlight and fog-light controls

National Highways recommends dipped headlights rather than full beam, which can reflect back from the fog and worsen your view. Wipers and demisters help keep the glass clear. Find these controls while parked, including how to cancel the fog lights afterwards. Official fog-driving advice.

In Great Britain, headlights are required when visibility is seriously reduced, generally below about 100 metres. Fog lights may be used in those conditions but must be switched off when visibility improves. They are not for routine use merely because the weather is grey. Highway Code rules 226 and 236.

Do not use an illuminated dashboard as your only evidence that the exterior lights are correct. The useful check is the actual lighting mode and its indication in your car. If you are unsure, resolve that before driving rather than searching through controls in poor visibility.

Avoid anchoring your judgement to the car ahead

A pair of tail lights can become a tempting visual target when the rest of the scene is indistinct. Following them closely does not tell you whether the driver has seen a queue, a bend or an obstruction.

Imagine the vehicle ahead disappears into a denser patch. Accelerating to regain sight of it would make your decision depend on keeping contact with that vehicle, not on the road you can assess. Let it go rather than chasing a reference point.

Equally, do not speed up because someone behind wants to travel faster. The Highway Code specifically warns against accelerating away from a vehicle following too closely in fog. Your safe view has not increased just because another driver is impatient.

Expect the view to change along the route

National Highways explains that fog can be localised. A warning sign may refer to fog ahead even when the immediate road appears clear. Do not dismiss it on the basis of the few metres currently visible around your car. National Highways fog guidance.

A useful way to discuss this with an instructor is to compare two moments: the point where visibility first begins to deteriorate and the point where it is severely restricted. Preparation should begin at the first clue, not after the scene has already vanished.

When conditions improve, reassess rather than immediately returning to the speed you used earlier. Ask what you can see now, whether the improvement appears sustained and what the traffic is doing. Avoid treating every clear patch as permission to make up lost time.

Separate fog outside from mist on the windows

If the view is poor, identify whether the problem is outside, on the glass or both. A dirty or misted screen adds a separate obstacle to the weather itself. The Highway Code's vehicle-maintenance guidance requires a clear view and proper maintenance of windows, lights and mirrors.

Practise the demister controls before the journey. You should not need a long glance away from the road to remember which button directs air towards the windscreen. If you cannot maintain an adequate view, do not continue on the hope that it will clear later.

At junctions, uncertainty is information

A familiar junction can be unfamiliar in fog because the view has changed. Knowing where vehicles normally appear does not establish that the approach is clear now.

For Northern Ireland, nidirect's fog guidance advises stopping in the correct position at a restricted-view junction and listening for traffic, then emerging only when satisfied it is safe. Silence alone is not an all-clear signal: it is one piece of information, not a replacement for observation.

If the conditions make a junction or route unsuitable for your current ability, discuss the decision with your instructor or supervisor. Do not improvise an abrupt stop in a live lane merely to reconsider the journey; identify a safe stopping opportunity and follow the rules for that road.

Review the decisions after the drive

Once safely parked, record which task was difficult: identifying the light controls, judging the visible road, resisting pressure from another driver or spotting a change in conditions. That gives the next lesson a clear purpose.

Our theory-study plan can help organise the rules alongside practical learning. Explore driving courses or contact Learn and Drive to discuss an appropriate plan. Good fog driving is not about proving you can continue regardless; it is about making a safe decision with the limited information available, including choosing not to start.