When shopping for new headlights or fog light bulbs, whether replacing your stock halogens or looking to upgrade to a brighter alternative such as LED headlights, you will come across different bulbs for different beams.
In order to purchase the right product, it’s important to understand the different beams, when they are used, and their purpose. In short, the low beam is the primary source of light and most frequently used lighting function while the high beam is a secondary source of light used rarely in very dark settings such as on dark roads, the country, etc.
After reading this guide, you’ll understand the differences between low beams and high beams. We’ll also explain when you should use your low beams and high beams and conclude with some questions on this topic.
What Are Low Beams?
Low beams are the ‘normal’ lights your car headlights emit and are used when driving at night or in a dim or dark setting such as an indoor parking lot. Low beams have a short-range focus and are sometimes referred to as ‘dipped beams’.
Low beams are the most important and most frequently beam used in a car. The light beam is angled towards the ground in order to illuminate the road and to avoid blinding other drivers. They are a way for other drivers to see you.
Traditionally, drivers would have to manually turn on their low beams but newer cars do so automatically by detecting low light environments such as during the night or when entering a dim parking lot.
When to Use Low Beam Headlights?
It’s much more common to use your low beams, which can be used in a variety of situations.
Low beams should be your go-to pretty much 24/7, however, your high beams can be used to see better at night, and in urban or rural areas. Your low beams should be utilized during hazardous weather, when passing by other vehicles, or following someone.
Unless high beams are required for proper visibility, drivers should always keep their low beams on when driving to make it easier for other road users to see them, even in daylight, according to William E. Van Tassel, manager of AAA Driver Training Programs. Low beams are also the best choice in the following situations:
- At night on busy roads
- In the rain
- In the fog
- In the snow
- In smoke or haze
What are high beams?
The high beam headlight lighting function is normally activated in environments with little to no light such as the country or small roads with no street lights. High beams are sometimes referred to as ‘brights’ or ‘full beams’.
The light beam for high beams is angled upwards in order to illuminate a surface area above and beyond the light of the low beams. High beams have a long-range focus.
Unlike low beams, high beams will never turn on automatically. They must be manually turned on by the driver when needed. In fact, high beams should only be used for short periods of time when extra light is really needed.
Driving with your high beams can blind oncoming traffic, which can be very dangerous. Keeping them on for an extended period of time is illegal.
When to Use High Beam Headlights?
High Beam should be used when your visibility is severely compromised. But they should be used carefully and only in certain circumstances.
The most common reason you would want to use your high beams is when you have poor visibility at night. Your high beams make [seeing] significantly easier in general as well as increase the reflections of road signs, such as stop signs or yield signs. High beams can also come in handy when you’re in areas that have little to no light exposure. Roads that have trees overlapping them are significantly harder to see down during the night or at dusk.
The best times to use high beams are when you’re driving on:
- Rural roads or highways, where it’s extremely dark;
- City roads or highways with poor lighting and visibility.
However, it should be noted that high beam use may be illegal in certain instances and may vary by state. Generally, you’re required to dim your high beams if there are oncoming drivers or if you’re following another car closely. Why? Because high beams are so powerful they could temporarily blind another driver, obscuring their vision and creating a hazardous situation.
In essence, high beams should only be used in situations where visibility is an issue. For example, driving on a rural road that has few streetlights or on a stretch of highway at night with no lighting.
Though it may seem counterintuitive, you should not use high beams in extreme weather conditions. These include:
- Fog
- Rain
- Snow
- Smoke
This strategy can backfire as the high beams mixed with these conditions will reflect back and cause glare, making it more difficult to see.
Dual-Beam Headlight Systems
All cars and trucks come with a low beam and a high beam function; however, some cars require two separate bulbs for each beam (single beam systems) while others require only one bulb (dual beam systems) for both.
Drivers that have cars with dual-beam systems will only need to buy one set of bulbs to replace (or upgrade) both low and high beams. Dual-beam bulbs are typically slightly more expensive than single beam bulbs and draw more power.
Difference Between Low and High Beam Headlights
The main difference between low and high beam headlights is that a low beam is used for normal nighttime driving, whereas high beams are used for driving in rural areas or small roads that feature little to no light.
A low or dipped beam is the projection of light in a lateral and/or downward fashion. Its main purpose is to provide adequate lighting without reducing your visibility of oncoming traffic.
However, when it comes to high or full beam lights, the light distribution is more centralized, allowing you to see a long stretch of the road. These lights are primarily used in poorly lit areas.
Low Beam vs High Beam Comparison:
| Comparison | High Beam | Low Beam |
| Beam Angle | Straight/Upwards | Towards the ground/road |
| Focus | Long-range | Short-range |
| Light Coverage | ~100 meters | ~40 meters |
| Best For | No light environments (rural areas, small roads, etc.) | Normal Nighttime driving / low light environments |
| Activation Period | Short period / as long as no other cars are within 150 meters | Must always stay on when in low or no light environment |
| Blind other drivers | Yes | No |
| Activation | Manual | Automatic or Manual |
| Legal | Yes | Yes |
| Halogen | Yes | Yes |
| LED | Yes | Yes |
| HID/Xenon | Yes | Yes |
Functionality
To ensure optimum effectiveness, both low and high beam lights have distinct functions based on the intensity and projection of light. The general rule is to engage low beams when the oncoming traffic is within a distance of 150 meters or around 500 ft.
People in well-lit city areas, where there is a healthy flow of traffic always use low beams. This prevents them from blinding oncoming drivers, ensuring a safer environment for everyone.
Contrary to popular belief, in extreme weather conditions like rain, fog or snowfall, one should switch to low beams. This is mainly because the water molecules reflect the light from high-beam headlights. That, in turn, would make it all the more difficult for drivers to have a clear view of the road. The water spots usually blur everything in front of you.
People tend to use high beams in rural areas or in the dark for better vision. Doing so will prevent you from blinding the driver in front of you due to the reflection in the rear-view mirror.
Low Beam Advantages
- Fewer accidents. Using low beams can ensure greater safety for oncoming traffic and of the vehicle in front of you.
- Ideal for extreme weather conditions. Be it rain, fog, or snow, you should use low beams in order to have better visibility of the road. The light particles won’t bounce off of the cloud particles and blind the driver.
- The civilized way to travel. The beam won’t cause strain on the eyes of pedestrians, cyclists and motorists alike.
High Beam Advantages
- Better visibility. Due to greater intensity in the projection of light, high beams are ideal in poorly lit areas or on deserted highways.
- Can be used as a signaling device. We can flash our high beams to warn people of the vehicle’s presence or to signal the right of passage.
- Curbing noise pollution. Flashing high beams at night, instead of using your horn, can reduce noise pollution.
Low Beam vs High Beam Symbol
Low Beam Symbol
When the low beam is lighting up, the above symbol will illuminate on the dashboard. A low beam symbol is an image of a headlight with some diagonal lines. As you can see the rays point down towards the ground more than they point forward.
High Beam Symbol
This symbol is what you will find on the dashboard when you switch to high beam mode. High beams emit the ray point towards the front than to the ground.
Final Thoughts
Once upon a time drivers were required to get out of their car to switch between low and high beams. Now, one can achieve the same with the turn of a knob, nestled comfortably inside the car.
The world has changed significantly, and you are now able to take advantage of the latest automotive innovations. Something small like automatic headlights that turn on the moment they sense it dark outside serves as an additional safety feature in a vehicle.
Still, you should ensure the safety of your fellow travelers isn’t compromised due to your laziness. On-road driving is a team sport and we should strive to be team players.