Q: I have noticed a high number of cars and trucks without their lights on in bad weather. But here’s the thing – about 75 percent of them are black, dark blue, dark gray – the color of wet asphalt. I’m clueless about why people with dark-to-black cars see no need to turn their headlights on, especially close to sunset on rainy days. I often don’t see them coming from behind. Any ideas?
A: I just stepped out of my office and took a look at the cars parked along my street. Of the 25 cars I can see, 16 are black, gray or silver. That’s higher than national studies showing that these colors make up around 52-55 percent of vehicles on the road. If our choice of car color is correlated with the clothing color choices for the typical Washingtonian, that makes sense.
As a traffic safety advocate, I was about to propose that we only allow lemon yellow and lime green cars on the road, but then I realized that I’d feel like I’m perpetually in a Sprite commercial. There’s a simpler solution: turn on your headlights whenever you drive, if your car doesn’t already do it for you. Yes, gray cars are harder to see on a rainy day than yellow cars, but good lighting has a much greater impact on visibility than the color of your car.
In Canada and most of Europe Daytime Running Lights (DRLs) have been required on new vehicles for years. (They’re lights that come on automatically whenever the car is driving). Here in the US, it’s permitted but not required. While DRLs aren’t exactly headlights, during the day they achieve the same function as turning on your headlights – making you more visible to others.
I suspect that the reason more of us don’t use our headlights during the day is because we have an incomplete understanding of their purpose. The law requires drivers to turn on their headlights from a half hour after sunset to a half hour before sunrise and whenever visibility is poor. That language kind of implies that headlights exist to illuminate the road for drivers. That’s true, but it leaves out an important function of vehicle lighting – allowing other road users to see you.
There have been numerous studies evaluating the safety of using headlights during the day. The most quoted one, from the National Highway Traffic Safety Administration, found a five percent reduction in crashes. More importantly, daytime headlight use had a bigger positive impact for vulnerable road users. Crashes involving pedestrians and cyclists dropped by 12 percent, and head-on crashes involving motorcycles decreased by 23 percent.
One of the problems with turning on your headlights once it’s dark is that there’s a period during dusk when you feel like you can still see okay, but you actually have a reduced level of perception and you’re not very visible to others. If you don’t think to turn on your headlights until you need them to see where you’re going, you’ll have been driving during a time when it’s hard for others to see you and harder for you to see them.
Waiting until it’s dark to turn on your headlights is like the kid in school that only does just enough work to get a C+. I’ll admit that I’m still working on this. I’m getting more consistent at turning on my headlights when I start my car, but sometimes I’m still a C+ driver. We can help each other out here; seeing your headlights on is a great reminder to turn mine on too.
I’m not sure if the original question was addressed by your reply. I’ve seen several articles about drivers thinking their headlights and taillights are ON in poor weather because the daytime running lights are providing some forward illumination, and the normal digital dash display is illuminated. Their taillights are still OFF leaving the rear of a dark colored car nearly invisible to following drivers.
Yep, you’re right, and that’s a problem. Some daytime running lights don’t illuminate the tail lights, giving drivers a false sense of visibility. Here’s a bit more on that from a previous article: https://www.thewisedrive.com/headlights-taillights-turn-em-on/
An article on carkeys.co.uk dated 14 Nov 2016 said this about the photoelectric sensors used in automatic headlights:
“These sensors tend to rely on ambient light level rather than on visibility perceived by the driver. Therefore, automatic headlights may possibly decide to come on at times when the driver doesn’t think they are necessary. Alternatively, they may not come on instantly when conditions become darker or visibly poor in other ways, so drivers should be prepared to manually activate their headlights if there is a delay.”
Most people don’t understand the symbols on their lights to know which way to turn them. They can read the word “Auto” so that is where they stay.