THIS forgotten rule could land you in a spot of trouble when you're parking your car at night.
Motorists could be slapped with a fixed charge fine of up to £75 if they don't do this one thing.
When parking on a road or in a lay-by with a speed limit of more than 30mph, drivers must park with their sidelights on to avoid breaking the law.
Keeping these parking lights on all night ensures other vehicles can see where your car is parked on poorly lit roads.
The much-ignored rule from the Road Vehicles Lighting Regulations 1989 could land you a non-endorsable Fixed Charge notice from the police.
This could set you back between £35 and £75, according to the RAC.
Stretches of road leading into towns and cities are the most likely to catch you out, where the speed limit is 40 or 50mph and there are no street lamps.
The road law also dictates that drivers leave these little sidelights on when parking anywhere in fog.
The parking lights are usually next to the headlamps in the front corners of a car, and in most motors have their own switch position on the dashboard.
Running on a much lower wattage than your normal headlights, you should be able to leave sidelights on all night without running down your battery.
An RAC spokesman said: “For many drivers their knowledge of the law and rules relating to parking and the use of sidelights is at best sketchy if not non-existent.
“The law states you should use your side or parking lights when parking in the hours of darkness on any road with a speed limit over 30mph.
"Failure to do so could result in a non-endorseable offence and a fine of up to £75.
“There is minimal enforcement of the law on the use of parking lights.
"We would encourage drivers to use their common sense when parking in unfamiliar locations or areas and to use their parking lights where they think it will warn other drivers particularly in foggy conditions – or alternatively park elsewhere.
"Many drivers fear that they will quickly run down their battery if they leave these light on and some modern vehicles do not permit you to leave them on at all when the vehicle is locked.”
And this isn't the only bizarre rule that could land you in hot water.
Drivers could be fined up to £2,500 or even face up to three months in jail for leaving a vehicle for too long on a private residential street.
Under Section 2 of the Refuse Disposal Act 1978 that anyone who abandons a vehicle, or parts of a vehicle on roads or land in the open air, can be issued a fixed penalty notice or prosecuted by authorities.
And this applies to private land and private roads too.
Similarly, angry drivers who honk their horn in traffic when they see red with road rage could be slapped with a steep £1,000 fine.
A car’s horn is designed to alert or warn another driver of your presence, not for aggressive purposes.
Under the Highway Code, rule 112 states: “The horn. Use only while your vehicle is moving and you need to warn other road users of your presence.
"Never sound your horn aggressively. You MUST NOT use your horn while stationary on the road when driving in a built-up area between the hours of 11.30pm and 7.00am, except when another road user poses a danger.”
Police can issue drivers with a fine for illegal use of a car’s horn which in most cases means a fixed penalty notice of £30.
