If you’ve never driven in Seattle-area traffic during an actual thick blanket of vapor, it feels like your car has suddenly taken off into a low-budget David Lynch film: everything is silent except for the muffled whirring of your engine; everything is hazy and distorted; there’s an unsettling bright glow coming from everywhere around you; nothing seems familiar—and all you can do is hope that somehow this will clear up soon without ending in tragedy.
If at any point during your journey you notice that your view through the windshield looks like a sad panda grilling some grey tomatoes, you may want to turn on your car’s yellow or white safety beacon: your fog lights.
Visibility is key while driving, especially when you’re traveling over 60 miles per hour around unfamiliar corners. The problem with visibility, though, is that it isn’t always clear (pun intended). One of the most common foggy conditions is known as a “fog bank,” in which the density and coverage of the fog vary greatly between 1/4 mile and far beyond a mile.
While it would be easy to just drive straight through this weather phenomenon, fog banks can lead to dangerous situations where visibility is sharply reduced or even nonexistent. That’s where fog lights come in!
These extra fog lights are added to your car for a very simple purpose: to illuminate the road ahead at short distances so that you can safely coast along without plowing into anything or anyone on either side of your vehicle. Nowadays, most cars have these lights installed near the bottom center of their front end and angled away from traffic back towards oncoming drivers (or, if you’re in the country and not driving on roads, wildlife).
How does our perception work, and why is our sight affected by fog?
Light is essential for our perception of objects in our environment. Human brains can process images received by our eyes in multiple ways, but each person’s brain operates differently based on how it perceives light.
Light patterns are used to identify moving objects and even determine emotion based on facial expressions. Without light, there would be no sight at all; we wouldn’t be able to see anything around us.
In such dark cases, where there is no light – we can make some!
Fog lights help improve visibility for this very reason—they make objects that are too far away or obscured by heavy weather conditions more visible for drivers who might otherwise struggle to notice them.
How do fog lights work?
These shiny beacons of light can indeed be a bit of a mystery to drivers, especially if you’re not used to driving on mountain roads in the fog. What are those odd fog lights?
A fog light is a special type of auxiliary front lighting that’s mounted low on the vehicle. Its placement is intended to provide increased visibility during inclement weather such as fog, snow, or rain. Because the main source of illumination for driving is still the headlights mounted high above, fog lights are intended to supplement them and provide illumination where it’s most needed: just above the road surface.
Since fog is typically close to the ground and reflects less light than clear air, it can be hard for drivers to see where they’re going. To address this issue, fog lights are angled down and aimed away from traffic (so as not to blind other drivers).
You might also notice that a fog light has a tighter “beam angle” than many other types of light fixtures (which may produce an oval-shaped beam). The tightness of this angle allows for greater intensity at lower distances but less brightness over long distances; it also reduces unwanted reflection off objects further away from your vehicle.
Another important aspect to consider about these lights is their brightness level. Due to their low angle relative to their surroundings (usually between 7-12 degrees), they don’t produce quite as much light as your car’s headlamps do—but they make up for it with increased proximity lighting. This means that you will have no trouble illuminating obstacles directly within close proximity of your vehicle (namely animals or pedestrians).
You’ll also see that fog lights are much smaller than standard headlights because they produce less light overall—and since all vehicles come from a factory equipped with them anyway, there’s no need for them to be any bigger!
But… are they like high beams that just illuminate further?
Fog lights are designed to illuminate areas that headlights miss—they’re aimed lower than headlamps to better light up road signs and curbs. They don’t cause glare that can happen with high beams because they aren’t meant to be used in high-traffic situations.
In addition, the lower beam of the fog light helps drivers see further down the road because there is less glare from cars behind them—this can help them avoid rear-end collisions when looking out for stopped vehicles up ahead.
You may also have noticed that some cars’ headlights are yellow, while others are white. The color of a bulb doesn’t matter as much since white light contains all colors of light anyway; plus: both colors provide optimal contrast against foggy conditions, but there are specific benefits for each color, depending on the context.
If you’re unsure whether you want white or yellow headlights, check out our article on Yellow vs. White vs. Amber Fog Lights.
Are fog lights still important?
While fog lights may seem like an unnecessary luxury, they make your life easier when driving in the fog. They’re designed to enable you to see where the road is and reduce glare from other headlights.
Fog lamps can also be helpful when driving at night since they don’t reflect as much light back into your mirrors and into your own eyes, which could catch sight of them and lead to a potential car crash. And if you’re ever in a situation where you need to get down to mere inches of visibility, fog lights are one of the last safety features to consider while still maintaining visibility through the thick mist that is quickly engulfing much of North America.
They’re designed to work in a particular set of weather conditions by making light bounce around and reflect off of water droplets suspended in the air and amplify them so you can actually see something.
When should you use your fog lights?
So when is it useful to use them? Well…fog lights cut through the fog by using a horizontal slash of light to illuminate signs or reflectors placed down low before the curve of the road, eliminating some blind spots caused by fog, rain, or snow.
Consequently, fog lights are the forgotten heroes of bad weather driving. Too often, they’re left in the dark and forgotten about, but when needed, they are invaluable. Fog lights are designed to be used in conditions where visibility is less than 100 meters or roughly three football fields. Such conditions include:
- Dust/ Sandstorm;
Consequently, if you live where there’s a lot of rain and especially snow, fog lights are an important piece of your vehicle. Fog lights help you see better in bad weather, but be aware that they’re not for driving around town at all times. Only turn them on when visibility is low due to rain, snow, dust, or fog (or other conditions in which visibility drops below 100 meters)
Even though fog technology has improved much since it was introduced in the 1950s, the underlying purpose remains: safety first. So keep your fog lights on while driving through heavy fog (or any other weather conditions where visibility is limited), and be sure to turn them off when there’s nothing to aid you in your vision as you drive.