Motorists have been warned they could be slapped with penalties for breaching a simple driving law as misty weather hits Britain.
Incorrectly using car fog lights can backfire with strict rules around how the vital safety tool should be used.
It comes as a thin cloud of mist hovers over much of Britain with reports of conditions in areas including Scotland, Merseyside, Shropshire and Nottingham.
The weather is likely to lead to poor road visibility with motorists required to press a certain switch.
Forgetting to turn on the fog lights completely or using them when it isn’t thick enough is both against the rules and could catch out unaware road users.
Car insurance and breakdown specialists at the RAC have issued a warning with specialists revealing the exact measurements to avoid falling foul of the rule.
The RAC explained: “Fog lights should only be used in the fog, when visibility drops below 100 metres (328 feet) which is roughly the length of a football pitch, this is stated by the Highway Code (rule 226).
“Not using your fog lights when appropriate could impact upon the safety of yourself and those around you when driving.”
The RAC stresses that road users should not use full beam in poor visibility for one simple reason.
The experts admitted that the fog will often reflect the light back which will reduce visibility on the road ahead even further.
Motorists should also never attempt to navigate only using the tail lights of the car in front as this “can give a false sense of security”.
Road users are likely to be fined £50 if caught wrongly using car headlights but other consequences may also be just around the corner.
Drivers may find their car insurance policy is invalidated if they are involved in an accident and the vehicle didn’t have the fog lights turned on properly.
The RAC added: “The Road Vehicles Lighting Regulations 1989 prohibits the use of front and rear fog lights to dazzle other drivers when visibility is not reduced or when the vehicle is parked.
“Confusingly, using fog lights in drizzle and rain is therefore not allowed. You are even eligible for a fine from the police if caught.”
