Drivers are being reminded to follow Highway Code rules on using headlights and fog lights in low-visibility conditions.

It comes after new warnings from the Driver and Vehicle Standards Agency (DVSA) highlighted widespread confusion about the law.

The agency highlighted potentially dangerous driving habits in bad weather.

Weather forecasts

Posting on social media, the DVSA drew attention to Rule 226 of the Highway Code, which states that drivers must use headlights when visibility is “seriously reduced” – generally when they cannot see for more than 100 metres (328 feet).

Front and rear fog lights may also be used in these conditions, but motorists are legally required to switch them off as soon as visibility improves, to avoid dazzling other road users.

The reminder comes as winter weather and seasonal fog increase the risk of collisions on UK roads.

According to Department for Transport (DfT) data, adverse weather and poor visibility are contributing factors in thousands of collisions each year, with fog, rain and snow significantly increasing stopping distances and reducing drivers’ ability to detect hazards.

Attitudes and responsibilities

Road safety charities have long warned that even experienced drivers tend to underestimate how much poor weather affects reaction times and judgement.

Research by insurer Aviva last year underlined the scale of the problem.

A survey of 1,600 drivers found that one in seven (14%) admitted they do not use headlights in low-visibility conditions, making it harder for others to see them.

Furthermore, 10% said they were unaware of the rules around headlight use when visibility is severely reduced.

The findings suggest that confusion about lighting rules remains common, despite repeated public information campaigns.

Martin Smith, Motor Claims Manager at Aviva, said the results were concerning, particularly given that many drivers choose to get behind the wheel even for short journeys in poor conditions.

“It’s worrying to see drivers incorrectly using their lights and misunderstanding the rules of the road,” he said.

“Not only does this make it harder for other road users to see you, it can also impact your own vision and increase your chances of having a collision. Lights can dazzle other drivers, especially when roads are wet, or there is snow around, so it’s important to pay particular attention when the weather is bad.”

What are you thinking

Driver attitudes to adverse weather are a growing concern for road safety groups.

Studies by organisations such as the RAC Foundation have found that many motorists feel confident in their own abilities in rain or fog, even while acknowledging that other drivers may be less capable.

This “optimism bias” can lead to riskier behaviour, including driving too fast for the conditions, following too closely, or failing to adjust driving style when visibility deteriorates.

In heavy rain, for example, stopping distances can double, while fog can reduce forward visibility to just a few car lengths, making sudden hazards difficult to spot in time.

The Highway Code contains specific guidance for driving in fog and other low-visibility conditions.

Rules 234 to 236 urge drivers to check mirrors before slowing down, use brake lights to warn vehicles behind, and maintain a safe following distance, as rear lights can give a false sense of security in thick fog.

Drivers are also advised to be able to stop well within the distance they can see clearly, particularly on motorways and dual carriageways where speeds are higher, and to use windscreen wipers and demisters to maintain clear vision.

Rule 234 warns that fog can appear suddenly, even when conditions seem clear, while Rule 236 makes clear that fog lights must not be used unless visibility is seriously reduced, as they can dazzle other road users and obscure brake lights.

Drivers who misuse fog lights or fail to use headlights when required risk not only causing danger but also facing penalties.

Understanding the basic

Road safety experts say simple checks can make a significant difference.

Ensuring that headlights, tail lights and fog lights are clean and functioning properly, reducing speed in poor weather, and allowing extra time for journeys are all basic steps that reduce risk.

With climate change linked to more frequent extreme weather events, motoring organisations warn that drivers may need to adapt increasingly to common challenging conditions.

The DVSA and insurers are urging motorists to refresh their knowledge of the Highway Code and think carefully before setting off in fog, heavy rain or snow.

For new drivers, understanding these issues, knowing the regulations and advice contained in The Highway Code, defensive driving techniques and driving responsibly according to the conditions, are essential foundational skills for safe driving for life.