Car Headlights Explained: The Best Tips to Know Now

This article explains how car headlights work, common maintenance issues to watch for and practical car headlight safety tips you can use year-round.

Quick tip: If you want to keep headlights performing well, add them to your regular maintenance routine instead of waiting for a bulb to fail. Clean lenses, check for fogginess and ask about alignment during routine service.

Add headlights to your car maintenance checklist

You change your oil and rotate and fix flat tires. But how often do you check your car headlights? According to Robb Waldner, Managing Vice President at Amica, most annual vehicle inspections don’t check your headlight brightness. “It’s up to you, as a driver, to stay on top of their performance.”

And it’s critical to do so. Recent research from the Insurance Institute for Highway Safety (IIHS) shows that 73% of pedestrian fatal crashes happen between 6 p.m. and 6 a.m. It makes sense — the farther ahead you can see, the safer you’ll be. According to data published by IIHS, if a vehicle is driving 55 mph, it can take more than 144 feet for it to stop once a driver brakes.

“You want car headlights that illuminate the road well enough to give you ample time to brake and avoid a dangerous situation ahead,” says Waldner.

Here’s a tip: Don’t wait until a bulb goes out before maintaining your car headlights.

Instead, check them whenever you get an oil change, perform regular auto maintenance or clean your windshields. Here are a few key ways you can keep your headlights working stronger – for longer:

• Wipe them clean.

Is your windshield dirty? Your headlights probably are, too. This can leave them dimmer and you at risk. The next time you clean off your windshield at the gas station, wipe down your headlights, too. It takes just a few minutes to remove snow, mud and other debris.

If you’re wondering how to keep car headlights from getting foggy, regular cleaning is one of the simplest places to start. It won’t stop every cause of haze, but it can keep buildup from making lenses look worse than they are.

• Make sure they’re aligned.

Potholes and bumps in the road can knock your headlights out of alignment. This means they’re not pointing in the right direction and can cause dangerous headlight glare. The next time you get an oil change, ask your auto technician to check your headlight alignment. They can let you know if there’s a problem and easily fix issues.

• Look for foggy or yellow lenses.

Over time, headlight lenses break down. UV rays from the sun can cause oxidation, and scratches happen with normal wear and tear. Even if your headlight bulb shines bright, lenses can become yellow or foggy. Check your lenses whenever you change your oil or get an inspection. If you buy a used car, take time to inspect the headlights. If they look worn, pick up a headlight cleaning kit at a local auto store.

You may come across DIY suggestions online, including advice about how to clean headlights with WD40. However, it’s best to use products intended for headlight lens care. Or ask a technician what’s appropriate for your vehicle’s lenses and finish.

• Check for bulb dimness.

Waldner says, “Car headlights, over time, will dim, as well as the reflective finishes within the headlight housing.” Ask your auto technician if you need a full headlight replacement, or if a general cleaning kit will do the trick.

Waldner recommends upgrading bulbs to LEDs, if possible. “If you have an older car with incandescent bulbs, consider whether your vehicle can accommodate LED bulbs, which last longer and shine brighter. Many LED replacement bulbs are now manufactured with connections that allow them to replace incandescent bulbs.”

These tips are especially important if you buy a used car, something more and more Americans are doing now. According to data from Research and Markets, the used car market is forecasted to be $885 billion by the end of 2026. The bottom line: Whenever you purchase a used vehicle, add headlight maintenance to your to-do list early on.

Troubleshoot common car headlight issues

Let’s say you notice a problem – either glaring, dimness or even a headlight that’s out. Here’s some good news. According to Waldner, most drivers can fix headlight issues on their own at a low cost. We’ve identified some common issues and how you can troubleshoot them.

First, pull your car up to a garage door or the side of a building to see the lights in action. Then, execute these common fixes:

• Issue: One or both of your car headlights doesn’t work.
  What to do: Change out the bulb(s). If the light still doesn’t work, ask a technician about a wiring or fuse issue.
• Issue: Your headlights appear dim.
  What to do: As mentioned earlier, pick up a cleaning kit or simply wipe off your headlights. Everyday dirt and grime can build up and cause the lights to appear dull.
• Issue: Your high beams, low beams or hazard lights don’t work.
  What to do: Check to make sure your bulbs aren’t out. If this doesn’t fix the issue, then ask a technician if there are wiring problems.

As you can see, most car headlight issues can be fixed with a quick cleaning or bulb replacement. This is good news for busy drivers looking for quick fixes. Waldner believes the tried-and-true solutions, like regular cleaning and replacing bulbs, make the biggest difference. Plus, these fixes have the potential to be relatively low-cost. “Depending on the make and model of your vehicle, these can be $10 to $15 decisions. Sometimes the simplest solutions have the biggest impact.”

Concerned about low-visibility situations? Try “How to Stay Safe on the Road While Driving in Fog” and “Safety Tips to Conquer Driving in Rain”.

Car headlights use laws in your state, explained

Now that your headlights are working, it’s time to learn when to use them. Take a few minutes to review the headlight use laws in your state and then make a commitment to abide by them. Remember, laws are there for a reason – to keep you and your passengers safe on the road.

For example, you’ll want to know:

• When to turn on your headlights.

Find out what times of day your headlights must be on. For example, many states require headlight use from sunset to sunrise. You may also want to use them on narrow or country roads with limited visibility.

• How to use your high beams.

Learn when you can use them and at what distance you should dim them for oncoming traffic.

• How to use your low beams.

Your low beams are ideal when driving in fog, rain and snow because they direct light downward and help reduce glare.

• If there are restrictions to using hazard lights.

Find out if you can use them to indicate hazardous conditions, when you’re parking, or if your car is disabled.

Remember, adhering to your state’s headlight use laws can protect you from a costly ticket, but more importantly, help keep you safe.

Want to explore more safety-focused driving habits? See “Facts and Statistics About Distracted Driving“ and “What to Do if Your Car Breaks Down: A Step-by-Step Guide”.

New car headlight technology explained: Is it worth it?

If you’re in the market to buy a new car, you may hear terms like “high-beam assist,” “adaptive headlights” and other buzzwords. The automotive industry is constantly innovating, but do these technologies really keep drivers safer?

Waldner says not necessarily. “Not all new headlight technology is created equally. There are wide differences in the function of various headlight designs that can significantly change the effectiveness of the headlights,” says Waldner. “You can refer to the IIHS headlight study that evaluates and rates headlight performance and innovations.”

Waldner says that some new technologies are excellent advances for vehicle safety. That being said, it’s just simply not feasible for everyone to upgrade to a new car for new safety features alone. If you do make the decision to upgrade your vehicle to one with more advanced headlight features, here are a couple that are particularly helpful:

• Adaptive headlights:

A unique safety feature, these are lights that respond to a driver’s steering by directing light around curves. They can increase a driver’s visibility at night or in low-light conditions.

• LED bulbs:

Light-emitting diode (LED) bulbs reduce energy consumption and last longer. They’re more expensive but are less likely to burn out.

Use these tips to give your headlights a thorough checkup. If you spot an issue, remember, it’s often a quick fix to keep your headlights working properly, and keep yourself safer on the road.