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Ask a Mechanic.....DRLs in the Dark

Today we’re discussing nighttime drivers with no running lights.

Every week, we answer your questions about what is going on with your vehicle. Today we’re discussing nighttime drivers with no running lights.


Dear Ask a Mechanic,

I have tried to get the Star Wheels to write something about my pet peeve but I have had no success. There is a very dangerous situation that I see every night. Many cars, often new cars, driving around at night with no taillights on. It’s very simple. Some people think that if their dash lights and headlights are on then their taillights must be on too. Many new cars have a setting that does not turn on rear lights. Contact the safety authorities and the car companies to get them to change the settings. – George Kinnear (Or “Afraid of the Dark Vehicles”)


This reader’s pet peeve is a point of annoyance for me too – the sizable number of folks driving around at night with either just their Daytime Running Lights (DRLs) on (and no taillights), or their DRLs in combination with their parking lamps.

The former situation is much more dangerous as it leaves the vehicle with no surrounding illumination other than from the front, but since a large number of models use their high beam headlights (at reduced intensity) as the DRLs, their light is still blinding for oncoming vehicles at night.

Of course there’s the added concern that the driver of that car has greatly reduced forward visibility with only the output of the DRLs, particularly in models using LEDs for that function. LED DRLs are often bright, but they are not a focused light source and would provide mediocre illumination at best.

The reader has nailed the main reason why these otherwise conscientious folks could drive around seemingly oblivious: many modern cars backlight their instrument clusters even during the day, and virtually all modern vehicles use backlit screens for audio and infotainment displays. Without a sea of blackness inside the vehicle to make it evident that their main lighting is currently off, the oversight is understandable, especially in urban settings where the missing headlight illumination isn’t apparent. Worse yet, some vehicles use their low-beam headlights as DRLs, removing that key visual indicator.

Fortunately, Transport Canada is aware of the problem, and in 2018 issued an amendment to the federal vehicle standard that addresses it in vehicles manufactured after Sept. 1 2021. Automakers now have three options: instruments that are not illuminated and conventional, switched light controls (as in current practice); illuminated instruments and the automatic activation of full vehicle lighting in low-light conditions, or; full-time activation of the taillights.

This will not fix the existing vehicle fleet, but as older ones are phased out, the problem will become a rarity.


Ask a Mechanic is written by Brian Early, a longtime Wheels contributor and a Red Seal automotive technician with over 25 years’ experience. You can send your questions to These answers are for informational purposes only.


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