headlight of a car

Headlights, Laws, and Road Safety | Everything You Need to Know

When was the last time you thought about your vehicle’s headlights? Do you know which headlights to use during fog, rain, sleet, or snow? How can you increase visibility and reduce glare?

While headlights may not always be top of mind, in order to keep the roads safe for yourself and others, it’s important to periodically check your headlights and know how and when to use them.

Use this guide to learn about headlights, headlight laws, and how to improve road safety for everyone.

When to Use Headlights

Headlight Laws

The law requires that you have two functioning headlights that are to be turned on whenever it is dark out, usually from sunset to sunrise. In Tennessee and Georgia, headlights are required to be turned on 30 minutes after sunset to 30 minutes before sunrise, when visibility it low, and in adverse weather conditions.

These conditions make it harder to see other vehicles. Turning on your headlights will simultaneously turn on your taillights, significantly reducing the chances of a rear-end collision.


Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, when visibility is less than 500 feet, and in conditions of insufficient light/adverse weather.


Headlights are required 1/2 hour after sunset to 1/2 hour before sunrise, during fog, smoke, or rain and when visibility is less than 200 feet.

In some states, headlights are required anytime the vehicle’s windshield wipers are on in continuous use. This indicates the presence of rain, sleet, snow. Other states require motorists to turn on headlights in construction zones.

Most states require high beams to be dimmed within 500 feet of another vehicle.

Click here for a list of headlight laws by state.

Note: When driving in a foreign country, read up on the headlight laws. Many countries, such as Scandinavia, require 24-hour headlight use.

When to Use Headlights During the Day

You may think it unnecessary to drive around with headlights on during the day, but they when there are varying light conditions, car with lights on are much safer and more visible.

Daytime headlight use is highly recommended (and sometimes required) during adverse weather conditions, such as fog, smoke, rain, snow, sleet, or when visibility is less than 500 feet.

Turn on your lights whenever you see a “daylight headlight section” sign.

The Department of Motor Vehicles recommends the use of headlights during the day when:

  • Adverse weather conditions make it difficult to see (rain, snow, sleet, fog, or smoke)
  • On rural and mountain roads
  • On narrow two-lane highways
  • Road signs indicate a daytime headlight zone
  • The sun is about to rise or set

If you are having a hard time seeing other cars, turn your headlights on. They are probably having trouble see you too. Don’t forget to turn your headlights off when you park.

What Are Daytime Running Lights (DRL)?

Depending on the make and model of your car, you may have daytime running lights (low-voltage headlights) to increase visibility and enhance safety on the road. Even though visibility is normally clear during daytime hours, cars with DRLs are easier to spot than cars without them. They also let people know if the car is approaching or receding. Nearly all cars manufactured today include DRLs.

Studies have shown that 24-hour headlight use with DRLs can reduce the chance of daytime collisions by 5-10 percent.

How do they work? Simple—they work automatically. If you have DRLs, they will turn on when the engine turns on and turn off when the engine turns off.

Daytime running lights can consist of your parking lights and LED lights around your headlights and taillights. 

While DRLs reduce your risk of collisions during the day, they are not suitable for nighttime driving. Make sure you turn your other headlights on when it gets dark or the weather turns for the worse.

While the increase in road safety may be small, there is no real drawbacks to using your headlights during the day. If you have an older vehicle, consider using your existing headlights 24 hours a day to reduce the use of daytime collisions.

While no state currently requires 24-hour headlight use, several states have introduced bills to make headlight use mandatory at all times. Keep on the lookout for certain roads that require daytime headlight use.

Source: Wikimedia Commons

When to Use High Beams, Low Beams, and Fog Lights

In order to maintain safety on the roads for yourself and other drivers, it’s important to switch your headlights to the proper setting according to the location, weather, and time of day.

High Beams

High beams are typically used on dark rural roads without much traffic. When there are no streetlights on the road, high beams can help you see further down the road to avoid hitting animals, pedestrians, and debris.

Consider using your high beams on:

  • rural or mountain roads (turn your high beams off when you are approaching another vehicle or when another vehicle is approaching you)
  • open highways when no other vehicles are present
  • streets and roads that have no lighting

Always abide by your state’s laws concerning headlights and high beams. High beams can be blinding and very dangerous for other vehicles on the road. Most states require high beams to be dimmed within 500 feet of another vehicle.

If you are driving with your high beams on, make sure you switch to low beams whenever there is oncoming traffic or you are approaching a vehicle from behind.

Avoid using high beams when other vehicles are around. Turn them off if you see oncoming vehicles or are driving in an urban area.

Low Beams

Use your low beams, also known as dipped headlights, when:

  • Poor weather makes visibility difficult
  • Driving in the fog (if you don’t have fog lights)
  • Within 500 feet of another vehicle (many states require dimming high beams to low beams when you are within a certain distance of a vehicle—check local headlight laws)
  • Road signs indicate a daytime headlight section

Fog Lights

When driving in fog, use your low-beam headlights or fog lights (if equipped). Do not use fog lights on clear nights as they can irritate other drivers.

Dashboard Headlight Symbols – Are Your Lights On?

High Beam Indicator Light

Source: Wikimedia Commons

Main Beam/High Beam Headlights – Your high beam dashboard light is usually blue with parallel horizontal lines. While these lights provide better visibility at night, they are not to be used whenever other cars are around. Use them mainly for dark rural and country roads. Never have them on when driving the highway.

To activate the high beams, consult your owner’s manual. Many times, it involves pushing the lever toward the instrument panel. To deactivate, pull the lever towards you. The high beam indicator light will illuminate on the dashboard.

You can also use your main beams to communicate with other drivers. Rather than using your horn, a quick flash of the high beams can let someone know their headlights are off.

Low Beam Indicator Light

Source: Wikimedia Commons

Low Beam/Dipped Headlights – Your normal headlights, also known as low beam or dipped headlights, point downward to reduce glare for oncoming traffic.

Use your dipped headlights between sunset and sunrise or whenever weather conditions make it hard to see. If fog is present and fog lights are not equipped, use your low beams.

Many motorists choose to use their dipped headlights during daytime hours to increase visibility (if daytime running lights are not equipped).

Fog Light Indicator Light

Source: Wikimedia Commons

Fog Lights – Fog lights cast a low, broad beam that helps increase visibility in foggy, misty, or hazy conditions. However, driving with them on in normal weather conditions is dangerous as they annoy other drivers and can cause accidents.

If equipped, you can switch to fog lamp mode using the main headlamp control. For proper operation, consult your owner’s manual.

Side Light Indicator Lights

Source: Wikimedia Commons

Side Lights – Side lights are the small, white lights on the front corners of your headlights. In some cars, the sidelight indicators will turn on when the normal headlights are in use.

Usually, when your side lights are on, the rear taillights and license plate lights will also turn on.

If your low beam lights are not working, use your side lights. It will at least show that you are a car (not a motorcycle) and will alert others whether you are approaching or receding.

Tips for Headlights and Road Safety

Here are some additional headlight tips to increase safety on the road:

  1. Regularly clean your headlight lenses (about once a month whenever you clean your windshield). They can quickly become dirty.
  2. While fogging is normal (caused by the temperature difference between the inside and the outside of the lens), if you notice water on the inside of the lens, contact your local mechanic or car dealer right away.
  3. You can help restore clarity and remove scratches from your headlight lenses with home remedies, such as toothpaste or insect repellent. You can also pay a professional for headlight restoration or purchase an inexpensive do-it-yourself headlight refinishing kit at your local auto parts store.
  4. If an approaching vehicle is using blinding high beam lights, reduce your speed and avert your eyes to the right edge of your lane.
  5. When using your headlights, drive slower and more carefully. Visibility is reduced and driving conditions are worse.
  6. During your annual vehicle inspection, ask your mechanic to check the headlights for correct aiming. Fix your headlights if they point in different directions.
  7. Check your lights regularly and replace them right away if they stop working. The law clearly requires both working headlights. It’s cheap and you can do it yourself. We recommend storing replacement bulbs and fuses in the vehicle for quick replacements.

Read our other articles for more driving safety tips:

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