Without much evidence to show they significantly reduce crashes in most driving conditions, rear Daytime Running Lights weren’t included when front DRLs became mandatory on all new vehicles sold in Canada in 1989.Kenneth Sponsler
With all the safety features today, why don’t cars have back running lights like motorcycles? I’m still amazed to see cars driving around at night with no taillights on. – Sue
While Ottawa takes a dim view of cars that let you drive at night without their lights on, it hasn’t made rear daytime running lights mandatory.
Daytime running lights (DRLs) are lights that turn on automatically when your car is started, even if your headlights are off.
Because DRLs are not as bright as headlights, they’re not meant for driving at night. Plus, because taillights only come on with headlights on most cars, when your DRLs are on, taillights are off. That leaves you invisible from behind when it’s dark or if it’s rainy, snowy or foggy.
Instead, since September 2021, there have been three options car makers must choose to make new cars visible from behind, and only one calls for rear daytime running lights.
While Transport Canada didn’t say why it didn’t require rear DRLs on all vehicles when it implemented the new rules, a safety expert said there’s still not much evidence to show that they significantly reduce crashes in most driving conditions.
That’s the same reason rear DRLs weren’t included when front DRLs became mandatory on all new vehicles sold in Canada in 1989.
“There’s not quite the evidence to suggest that rear [DRLs] would have the same safety impact as forward [DRLs],” said Lewis Smith, manager of national projects with the Canada Safety Council (CSC), an Ottawa-based not-for-profit.
The point of front DRLs is to make vehicles coming from the opposite direction or from the side visible to other drivers from a greater distance during the day. That gives drivers more time to react. Headlights, which are considerably brighter than DRLs, are designed to improve the driver’s ability to see the road at night or during poor weather conditions.
One 1997 study showed DRLs had reduced front collisions by about 15 per cent.
“Front [DRLs] give drivers a clearer perception of how quickly that car is coming,” Smith said. “That benefit isn’t necessarily seen from the rear, when cars are approaching from the rear.”
DRLs are not required in the United States.
Phantom menace?
Years ago, a dark dashboard was a clue that it was time to turn on your headlights. But when more cars started to use speedometers that are backlit all the time, drivers lost a key reminder that they were driving with their lights off. Drivers might think their headlights were on, especially in well-lit cities, but they weren’t lit at all from behind unless they hit the brakes and the brake lights lit up.
Enter the new rules. Now, car makers have to equip all new cars with one or more of three options. The first is always-on rear DRLs. The second is automatic headlights that sense light and automatically come on at dusk or, say, during a heavy daytime rainstorm. The third is a dashboard that only lights up when the headlights are on.
It’s up to the car makers to decide which options to use, Transport Canada said. It didn’t say which companies chose rear DRLs. It varies by car maker and even by model.
Volkswagen, for instance, said none of its cars sold in Canada have rear DRLs, but Volvo said its cars have rear lights that stay on all the time.
CSC’s Smith thinks automatic lights are a good option for many drivers so they won’t have to worry about remembering to turn on their lights – as long as they keep them set to automatic.
“There’s definitely a massive safety advantage to automating this kind of thing so that there’s less user input required,” Smith said. “We know that we can’t necessarily count on drivers to always make a smart decision.”
If your car doesn’t have rear DRLs, should you just drive with your headlights on all the time?
Smith said that’s a good idea when there’s poor visibility because of fog or a snowstorm but it’s probably not necessary for safety in sunny weather. Unfortunately, he said, there’s a risk of leaving them on when you park and draining your battery.
“Leaving them on all time is a bit tricky because a lot of cars do turn them off automatically when the vehicle turns off, but some still don’t,” Smith said. “What we recommend is keeping your headlights set on auto as much as you can. For the more heightened visibility needed during darker hours, you can’t beat automatic headlights.”
Have a driving question? Send it to globedrive@globeandmail.com and put ‘Driving Concerns’ in your subject line. Emails without the correct subject line may not be answered. Canada’s a big place, so let us know where you are so we can find the answer for your city and province.