Tips, Tricks & Trends

Why Don’t Cars Warn You When a Headlight or Taillight Is Out?

Headlights are so important for safe driving that, if you decide to go night driving without them, you’re sure to be quickly greeted with a very different set of lights — namely, blue and red flashing ones. Forgetting to turn your lights on and getting pulled over by law enforcement is one thing, but all too often drivers are surprised to hear from police officers that their headlights or taillights aren’t functioning.

Despite their great importance, these exterior bulbs can burn out without having too noticeable a difference on the average driving experience. So why don’t our cars tell us we need a replacement, before the cops do? 

Headlights and taillights are key components of safe driving

If your vehicle blew a tire, you’d feel the effects immediately. Because the loss of a light can go undetected, it’s easy to forget how essential they are for safe driving.

Whether you notice it or not, the brightness lost by the death of a single bulb can reduce visibility and thus reaction time. Although these milliseconds may be imperceptible when you’re behind the wheel, the Insurance Institute for Highway Safety (IIHS) points out that in 1.5 seconds, a car traveling at 55 mph will progress 120 feet. If an unexpected disturbance appears in the road, every second counts for braking. 

The same logic applies for taillights. Although they won’t guide your way, these rear bulbs help the drivers around you make smart navigation decisions. Taillights help to showcase the size and shape of your vehicle, as well as inform safe driving distances, during dark or stormy conditions. 

It’s easy to see how non-functioning exterior lighting could increase the odds of collisions. Their tremendous safety value begs the question — why don’t our cars let us know when these lights have problems? 

Many drivers lament the fact that their vehicles don’t alert them to an outage

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If you’ve ever been upset about your car quite literally leaving you in the dark, you’re far from alone. The Reddit group r/Cars hosted a discussion about the very topic, when u/RGregoryClark asked, “Why don’t cars have a burned out brake light indicator?”

He shared that his previous two vehicles were “heavy on the electronics” but still lacked any warning lights in regards to his rear bulbs.

Though no one could offer a true explanation for the absence of a simple dashboard alert, many echoed the original poster’s complaint. Some extended the woe to headlight bulbs, as well.

It wasn’t just Reddit that was hearing the frustrations — Consumer Reports‘ podcast received a fan question: “Why don’t automakers put a warning light on the dash to warn drivers that their headlight or taillight has burned out? I have accidentally discovered these outages on several occasions….” 

While Jennifer Stockburger, CR’s autotest operations director, validated these complaints, she couldn’t offer much of an explanation. “I really don’t know,” she began, in response. “With such a critical safety feature, you’d think it would.” 

Some cars already include the feature

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Stockburger also made one important clarification, which was echoed in the discussion on the Reddit forum: some vehicles do include these warnings.

One user, u/D1a1s1, wrote, “Some cars do. I know some BMW, MB, and VW cars have it from personal experience. I’m sure there are others.” The replies to his comment quickly proved that there really are others, and owners of these tech-savvy vehicles were quick to praise the feature. 

With any luck, the safety feature will soon come standard. After all, if dashboards can make room for a light telling you which side your gas cap is on, they can provide this simple protection.