Motorists are being warned that failing to turn on a certain switch in the car could land them a costly fine and even points on their licence. As the weather continues to stay wet this autumn you could be caught out by this legal requirement.

Staff at Select Car Leasing explained that drivers must use their headlights when driving in heavy rain - even if it’s broad daylight outside. 

It’s a legal requirement, according to The Road Vehicles Lighting Regulations 1989, to use dipped headlights when visibility is "seriously reduced". 

And the Highway Code says you must use headlights when you can’t see for more than 100 metres (328 feet) ahead - which is roughly the length of a football pitch. 

Graham Conway, managing director at Select Car Leasing, clarified that the guidance applies to heavy rain, not just fog or the onset of night.

Failure to comply can result in an on-the-spot £50 fine. However, drivers could also be hit with a charge of careless or inconsiderate driving under the Road Traffic Act 1988 - in which driving ‘falls below what would be expected of a competent and careful driver’. 

In those cases, not using headlights on wet roads could result in a possible £5,000 fine and nine points on a licence. 

Graham said: “Headlights aren’t just there to be used at night, they’re designed to keep everyone safe during daylight hours, too, and especially when it’s raining heavily. 

“We’re not just talking about using headlights when you’re unable to see a couple of cars ahead during the most extreme downpour, the law states that you should use headlights when you can’t see for more than 100 metres ahead. 

“That’s a relatively long distance, about the same length as a UK football pitch, so it’s important that you err on the side of caution and use your headlights as soon as the weather conditions deteriorate.”

The Highway Code says that you can also use your front or rear fog lights during heavy rain, but you must switch them off when visibility improves to avoid dazzling other road users. 

Select Car Leasing cautions that glare from lights can be a serious issue during inclement weather, when windscreens are drenched and visibility reduced. 

And there’s another little known vehicle lighting law that might come as a surprise to motorists. 

Rule 114 of the Highway Code says you should never sit with your foot on the brakes when you’re waiting at the lights or moving in stop-start traffic. 

Instead you should always use your handbrake - because doing so doesn’t cause your rear brake lights to illuminate, and therefore reduces the risk of dazzling a driver behind you. 

The Highway Code states: “In stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again.”

This particular section of the Highway Code is also backed-up by law in the form of ‘The Road Vehicles Lighting Regulations 1989’ and motorists face a £100 fixed penalty fine as well as three points on their licence if they’re caught by a police officer.