A new report suggests misused fog lights caused as many as 300,000 crashes in 2011, with many drivers leaving the bright beams on in non-foggy conditions for vanity reasons.
Research found that 14% of drivers left their fog lights on because it looks good, while a further 21% did so because their standard lights were not bright enough.
Younger drivers were more likely to leave their fog lights on for cosmetic reasons when conditions were clear, with 22% of 18 to 34-year-olds confessing to the offence. Just 3% of those aged 35-54 said they did so for the same reason.
The biggest reason given for fog lights being left on was simply forgetting to turn them off, cited by 40% of those asked. A further 27% said they did it by mistake. The final 11% were either not sure, or claimed it was for another reason.
Insurance company Swiftcover,com found that 8% of all drivers confessed to the misdemeanour, having surveyed 1600 adult motorists.
It is an offence to use fog lights unless visibility is reduced to 100m or less, and leaving them on inappropriately can bring a 30 fixed penalty notice.
Robin Reames, chief claims officer at Swiftcover.com, said: Fog lights are designed for a very specific purpose helping drivers to see and be seen when visibility is severely reduced.
Misusing these lights has the effect of dazzling and distracting other motorists and causes a staggering number of crashes.