22nd December 2017

Should rear daytime running lights be made mandatory if drivers and pedestrians face increased risks during winter months and in the dark?

As with everything in life, darker nights have their pros and cons. To many, it can feel irresistibly alluring to be able to close the curtains much earlier than at other times of the year and snuggle up by the fire in their PJs to watch one of the myriad streamed box sets. Large numbers love wowing passers-by with sometimes quite incredible Christmas decorations, while Halloween, Bonfire Night and Christmas carol concerts are the highlight of the year for others.

For road users, cyclists and pedestrians, though, the advent of dark nights heralds added dangers. Last year, according to government figures, pedestrian deaths trebled in December compared to September1 while the road user casualty rate rose by 56 from October to November. RoSPA, meanwhile, refers in its Driving at Night Factsheet to statistics highlighting that 40% of vehicle collisions happen when it’s dark2.

It’s now commonplace to see cars, vans and even HGVs adorned with a wide variety of eye catching ‘eyebrows’, ultra-bright but non-dazzling LED lights positioned somewhere near their headlights. They’re called ‘daytime running lights’ – DRLs for short – and originally started out as a safety move to make vehicles more visible in any conditions, day or night3. On cars fitted with them, DRLs automatically switch on when the ignition is started and they remain lit until its dipped beam or full headlights are turned on either manually or automatically. Where a manufacturer has combined a model’s DRLs with its sidelights, the former will dim when the latter are activated.

Illustrating just how beneficial European laws can be, twelve countries had made it mandatory by 2006 for headlights to be used all year round, even during the daytime. Sweden was the first to adopt this ethos all the way back in 1977, followed by Denmark, Iceland, Latvia, Macedonia and Norway by 1990 and Romania, Slovenia and regions of Portugal by the late nineties4.

At the end of the first year of DRLs’ introduction in Sweden, a reported 3% accident reduction resulted5, while the figure for Finland was given as an impressive 25%. A European Commission report extolled that the use of DRLs should place countries on the path to a 15% reduction in fatal road accidents, while the DfT here in the UK later concluded that universal DRL adoption would likely see a more realistic drop of upto 6% based on frank analysis by TRL6.

In February 2011, European Commission Directive 2008/89/EC made the fitting of DRLs a legal requirement7 for all new cars and light commercial vehicles (LCVs) or ‘vans’, a law which was then applied to HGVs from August 2012. Responding to one traditional criticism that DRLs put added strain on a vehicle’s alternator and reduce its fuel efficiency, EC Vice President Antonio Tajani commented following the law’s introduction8: “This is also good news for environment protection as the lower energy consumption rates will reduce CO2 emissions compared to normal lights.” Various automotive commentators say that DRLs generally use just 25-30% of the energy that standard driving lights require and, when LED technology is used, consumption falls by a further 10%.

Over the last few years, DRLs have resolutely turned into a fashion accessory, with the gamut of car, van and truck manufacturers proudly including in their press releases descriptions of their latest distinctive LED design signatures. From Jaguar’s ‘J-blade’ and Volvo’s “Thor’s Hammer” to Kia’s ‘ice cube’ quad-LED arrangement and the C-shaped DRLs that distinguish many of Renault’s models,  what started off as a safety feature is now an intrinsic component of car design culture and marques’ range identities. Even interactive quizzes have popped up online in recent years, car aficionados able to show off their knowledge by matching the presented DRLs with the correct models.

Returning to the fact that vehicles pose a greater risk for road users, cyclists and pedestrians when it’s dark, many have wondered why always-lit lights at the rear haven’t been made mandatory. It’s worryingly quite common to observe drivers who are apparently completely oblivious that they’re driving with neither any rear illumination whatsoever, nor their headlights activated. In most cases this is because they assume that their vehicles are suitably lit by virtue of the forward illumination provided by their DRLs. Semi-autonomous driving functionality is great but such technological features are making some drivers overly dependent on driver-assistance systems, the risk being that instinctive safety awareness can easily reduce.

We’re therefore always pleased to see organisations like GEM Motoring Assist periodically issue reminders in the media over the importance of drivers of vehicles fitted with DRLs also ensuring that they switch their headlights (and hence taillights) on9. Motoring expert Honest John has expressed similar concerns and wishes over rear DRLs10.

“By relying exclusively on your car’s automatic DRL setting, you will find yourself in the hazardous situation of having no rear lights on when it’s dark, or visibility is reduced because of poor weather”, commented GEM’s chief executive, David Williams, adding: “Not only is this illegal, it is also very dangerous and the risk of a collision is increased significantly. Someone could go into the back of you, it would be your fault, and they could claim off your insurance.”

One primary reason behind opposition to their introduction is the belief that they would result in driver desensitisation in relation to braking, motorists who are perhaps tired or generally not as acutely aware as others potentially failing to observe that a vehicle in front of them is braking because they’re used to seeing its relatively bright LEDs which may clash or blend in with the glow of the brake lights11.

Countering this assertion, Angelo DiCicco from a driving school in the States reckons that “if you’re driving during the day with your low beams on and your taillights on, you’ll get a better following distance from the people behind.” He believes that always-on taillights desensitising drivers is a misnomer and recommends that drivers activate their dipped beam headlights (and hence rear lights) at all times, to make them more visible to others. We certainly can’t argue with his recommendation and agree that it will reduce the number of what he calls “ghost cars” on the road, with unlit rears.

A small number of models do now come equipped with rear DRLs but they tend to be premium models, examples including the Evoque, F-Pace12 and XC90, plus certain Hondas and Toyotas in specific markets. Permanently-lit rear lights that illuminate when a vehicle’s ignition is activated are not mandatory and hence not commonplace on all new models, but perhaps they should be.

It’s certainly positive when manufacturers do configure new models so that their rear lights are activated automatically in one form or another along with the front DRLs when the ignition is switched on. It seems, though, that implementation has been quite erratic, with firms adding such functionality to their sixth generation model, for example, before dropping it13 from the seventh.

Canada appears poised to make always-lit rear lights mandatory for new models by 2020 and it would surely be something to be embraced if the UK government makes the same move, albeit Brexit is muddying imminent legal updates somewhat. In the meantime, then, all motorists can just try and remember that DRLs shining brightly doesn’t always mean that their vehicles are also lit up at the rear – which is perhaps a little suggestion that can be shared with elderly, newly-qualified or less confident drivers over the festive period.


1. https://www.rospa.com/rospaweb/docs/advice-services/road-safety/british-summertime-factsheet.pdf
2. https://www.rospa.com/rospaweb/docs/advice-services/road-safety/drivers/driving-at-night.pdf
3. https://fleetworld.co.uk/daytime-running-lights-become-mandatory-on-eu-new-cars/
4. https://www.theaa.com/driving-advice/safety/daytime-running-lights
5, 6. https://trl.co.uk/sites/default/files/PPR170.pdf
7. http://www.autoexpress.co.uk/car-news/100725/what-are-led-daytime-running-lights-and-what-do-they-do
8. https://fleetworld.co.uk/daytime-running-lights-become-mandatory-on-eu-new-cars/
9. http://home.bt.com/lifestyle/motoring/motoring-news/drivers-with-daytime-running-lights-reminded-to-switch-on-rear-lights-at-dusk-11363997309097
10. https://www.honestjohn.co.uk/askhj/answer/40846/why-no-rear-daytime-running-lights-
11. https://www.theglobeandmail.com/globe-drive/culture/commuting/do-rear-daytime-running-lights-cause-accidents/article26077653/
12. https://www.fpaceforums.co.uk/viewtopic.php?t=2860
13. https://www.pistonheads.com/gassing/topic.asp?t=1560582
14. http://driving.ca/auto-news/news/government-finally-shining-a-light-on-dimmed-tail-lights