Since 7th February 2011, all new EU cars and small vans must have dedicated daytime running lights (DRLs), to improve road safety but a survey by the RAC shows these lights cause unintended confusion for some drivers.

While all new vehicles must have daytime running lights at the front, they aren’t mandatory at the rear and this issue is what appears to be causing confusion and annoyance for road users.

Illuminating facts

Daytime running lights are lights fitted into a car’s existing headlights and taillights. The lights shine white at the front and red at the rear. These lights began in Nordic countries with low light levels during winter and, in 1977, Sweden was the first country to make them mandatory. Seven years later, the Volvo 240 became the first vehicle on UK roads with DRLs.

Studies show that DRLs can reduce the risk of road accidents; a 2008 American study on the effectiveness of DRLs on road safety reported only a 0.3% reduction in collisions while a 2003 EU investigation suggested a reduction in multi-party collisions of between 5% and 15%.

Research by the RAC now shows that many drivers don’t turn on their dipped lights or sidelights in dull driving conditions, perhaps assuming, because they have DRLs on at the front, the same applies to the rear lights.

In a RAC Opinion Panel survey of 2,061 motorists, 62% said they saw cars and vans driving around in dull overcast conditions with lights on at the front of their vehicles, but with unlit rear lights.

When asked whether the car they drive most often had DRLs, and if so, were they fitted to the front and/or back of the vehicle, survey respondents answered in the following ways:

Vehicle has no DRLs: 47%
Vehicle has front DRLs only: 29%
Vehicle has both front and rear DRLs: 14%
Vehicle has front DRLs, but driver uncertain if the car had rear DRLs: 8%

‘A very worrying finding’

Head of PR and External Affairs at RAC, Pete Williams said of the Opinion Panel survey results:

“This is potentially a very worrying finding as it implies that many drivers are driving without any rear lights believing that because they have running lights that switch on automatically at the front, they are also on at the rear.

“Alternatively, and arguably just as concerning, these drivers could simply have decided the light conditions were not bad enough to merit turning on their dipped lights or sidelights.

“While daytime running lights are clearly bringing a very valuable safety benefit to the UK’s roads, it would be good for every driver to take just a few minutes to make sure they know whether the vehicles they drive have them or not. And if they do, then check to see if they have them at the rear as well as the front. That way those that don’t have them at the back will be far more likely in poor daylight visibility to switch on their dipped lights to make their vehicle more easily seen from behind.

“We strongly urge everyone to carry out this check as those few minutes could make an important road safety difference.”

Dazzled by science

Fitting DRLs isn’t essential—vehicles produced before February 2011 do not need retrofitting—but fitting them may prevent an accident. If you want to fit DRLs in your car, you can choose from various aftermarket kits—look for an embossed approval mark on the lamp containing the letters ‘RL’. If you’re fitting DRLs, install them, so they come on with the engine and go off when you switch on the headlights. The lamps should come with fitting instructions but contact a qualified auto electrician if you’re in any doubt about fitting them. You might, instead, use your car’s existing sidelights during the daytime although they won’t be as bright as DRLs.

It is becoming more common for DRLs to contain light-emitting diodes (LEDs). LED lights consume little energy, which helps keep fuel consumption as low as possible. Using DRLs instead of driving with headlights or sidelights also means that rear lights and instrument lights aren’t on during the day.

LED DRLs are brighter, making them easier to spot in daylight. Manufacturers designed DRLs to make cars more obvious to other road users in daylight conditions, not to illuminate the road ahead.

Daytime running lights switch on when the engine is running. They should usually switch off when you turn off the main headlights but if yours don’t, make sure you turn your DRLs off when it’s dark, or they will dazzle other road users.

Although the UK has never brought in a rule requiring daytime use of headlights, your lights are an important part of your visibility on the road. By checking your car’s bulbs often you protect yourself and other road users.

Does your car have daytime running lights? Are you aware if your vehicle has them fitted at the rear, too? Are DRLs a problem? Share your opinion in the comments.