ONE-IN-EIGHT motorists is risking the lives of other road users by using their fog lights in clear weather.
And many are failing to maintain the headlights on their cars, trucks and tractors, according to a report published today by the Road Safety Authority (RSA).
Motorists are driving on just one headlight at night-time, and are being mistaken for motorcycles by oncoming drivers.
Drivers in Cavan are the worst offenders for blinding other motorists with illegal fog lights, with almost a quarter of car drivers in the county guilty of the illegal practice.
Some 23pc of Cavan drivers incorrectly use their fog lights, followed closely by motorists in Cork (22pc) and Offaly (19pc). Using fog lights in clear weather is a motoring offence as they can dazzle other drivers, which could result in a crash.
The study examined the behaviour of 53,881 drivers and found an average of 13pc of them have their fog lights switched on even when there is no fog present. The penalties for misuse of fog lights are €1,000 for a first offence and €2,000 for second or subsequent breaches.
The drivers best behaved over the use of fog lights were in Limerick, where just 5pc had them on in fog-free conditions.
The authority claims there "is a major problem on our roads with poorly lit vehicles.
"In fact, a number of vehicles on the roads are travelling with only one working headlight and are often mistaken for a motorcyclist, which could lead to a serious collision.
"Badly adjusted headlights are also a danger on the road as they can limit the driver's vision on the road, and can also dazzle oncoming traffic which can cause a collision."
The RSA is advising all motorists to use dipped headlights, known as daytime running lights, during the day.
Noel Brett, RSA chief executive, said: "I would urge every road-user to make sure all of your lights are in proper working order before you start your journey. Think about it -- how can you be safe if you can't be seen?
"Just take a couple of minutes to turn on your lights and check them before you start your journey as this simple check could be the difference in you coming home safely tonight."
Mr Brett warned that drivers caught with broken lights face a fine of €1,000 on conviction.
"Never use rear fog lights in normal driving conditions as they tend to blind traffic coming behind you," he said.