Q: Why would someone in a gray car drive without their headlights on when it’s a foggy day?
A: How about I answer a rhetorical question with a non-rhetorical answer? And yes, I just started a non-rhetorical answer with a rhetorical question. Also, is a non-rhetorical answer even a thing? Probably not, but this isn’t an English lesson, so let’s talk about headlights and fog.
This time of year, morning drives can feel like swimming through soup, or at least a stout broth. On a foggy day turning on your headlights can help, but are they required?
At a glance, the law makes it seem like the purpose of headlights is so that you can see better. And that’s not wrong. It’s just incomplete. You know you’re required to turn on your headlights when it’s dark, but Washington law also requires headlights “when, due to insufficient light or atmospheric conditions, persons and vehicles on the highway are not clearly discernible at a distance of one thousand feet.”
As long as you can see a person or car one thousand feet away without your lights on, you don’t need to turn on your headlights, right? I don’t think so. Maybe I’m making the law work too hard, but I think the law also applies if you’re not visible to others. If you’re “not clearly discernable” from one thousand feet you need to turn on your headlights.
I’ve mentioned one thousand feet several times now, but how good are we at actually estimating distances while we’re driving? Apparently, pretty bad. In one study the participants were off in their distance estimates by as much as, well, let’s just say the researchers called them “extreme errors.”
Since we’re bad at estimating the distance we need to know to comply with the law, allow me to suggest a different approach. It’s not law, but it is good practice: If your driving visibility is less than what you experience on a clear and sunny day, turn on your headlights. Actually, I’d go as far as to suggest that if you really want to be seen (and you should want that when you’re driving) turn on your headlights no matter the weather.
And what about car color? The top four car colors as reported by CarMax are (and they say they’ve sold nine million cars so they should probably know), in order of popularity, black, white, gray and silver. Side note: How boring are we as humans that we mostly buy cars somewhere on the gray scale? And according to researchers at Monash University, the vehicle colors with the highest crash risk (presumably because they’re hardest to see) are black, gray and silver.
You might like the understated elegance of a gray car, but on a foggy day it’s like your car is dressed in camouflage. However, there is some good news. Those same researchers found that as soon as you turn on your headlights, you eliminate any color-based increase in driving risk. So turn on your headlights.
Beyond headlights and car color, I have a few more suggestions for driving in fog:
- Use low beams – high beams can reflect off the fog and create glare, reducing visibility.
- Increase your following distance – instead of leaving three seconds between you and the car ahead of you, leave at least six seconds.
- Slow down – don’t outdrive your vision.
- Turn on wipers and defrost – The humidity that creates fog also collects moisture on both sides of your window. You might not even realize that part of your visibility problem in the fog is the windshield itself.
The simple answer to the original question is, “no good reason,” so let’s use our headlights and be seen.