How Well Can You See Ahead?
Many new drivers are uncertain when to use of low beam and high beam headlights. This also creates problem on the DMV knowledge test when they get questions about the use of headlights.
Think about this: low beams let you see about 200 feet ahead.
This is the distance it takes to stop a car when you drive at 30 mph (200 feet is almost half a city block in length).
If you cannot see 200 feet ahead, driving at 30 mph (or faster) is not safe. By the time you see an object in your path, it is too late to stop without hitting it.
Headlights on “upper” or “high” beam let you see about 350-400 feet ahead.
400 feet is your approximately stopping distance when driving at 50-55 mph. The distance is about the length of a city block.
In other words, high beams let you see twice as far as low beams. The faster you go, the more important it is to see well ahead. In a study of high-beam use, Insurance Institute for Highway Safety (IIHS) found that 80 percent of drivers fail to turn on their high-beam lights when they should.
Driving at Night
Adjust your speed.
When you cannot clearly see the road ahead, you should start by adjusting your speed. Never overdrive your headlights.
Do you remember the basic speed law? It tells you, that you must adjust your speed to existing conditions, which include limited visibility.
Be aware of your following distance.
Poor visibility also means you should increase your following distance. It is harder to see things at night because your eyes must constantly adjust to changing levels of light. This affects your reaction time and your total stopping distance.
Add 1 – 3 seconds to your normal following distance.
What does Overdriving Your Headlights Mean?
Overdriving your headlights means that you are driving so fast that you will not be able to stop within the distance you can see with your headlights. If there is an obstacle outside the area you can see ahead, you will not have enough room to make a safe stop and can end up in a crash.
It is almost like driving blind.
When Should I Use High Beam Headlights?
Outside cities and in rural areas.
In general, you should always use high beams outside cities and in rural areas if there are no other vehicles around. Dim your lights when there are oncoming vehicles, or when you are approaching another vehicle from behind.
During poor visibility it is particularly important to use high beams on unfamiliar roads, in construction areas, or where there may be people or bicyclists along the side of the road.
In city areas with no streetlights, your first action should be to slow down. Use high beams only to get a clear view of the road ahead and only if there are no other vehicles nearby.
Never drive with high beams in heavy traffic or in normal light environments when you see can pedestrians and vehicles early enough to stop – when necessary.
Following Other Vehicles outside Cities
When following another vehicle, you should never use high beam headlights. High beams reflects in rear-view mirrors and may blind the other driver.
State laws usually say you must dim your lights when you are within 200-300 feet of the vehicle you are following. Dim your headlights in all situations when there is a risk of blinding other drivers with your high beams.
If you keep your headlights on high beam, you must drop back.
When Should I NOT Use High Beam Headlights?
You should not drive with high beam headlights when approaching another vehicle from the front or from behind, when the roadway is sufficiently lit by daylight or streetlights, or when driving in fog, rain, or snowfall.
It is important to know that high beams will not always improve your visibility. Sometimes they will do the opposite.
This happens in fog, heavy rain, or a snowfall.
In these situations, the light from your high beams will reflect from the fog/rain/snow and cause glare. This glare from your own headlights will make it hard for your eyes to adjust and make it difficult to see the road ahead.
To improve visibility, you should switch to low beams. It reduces the glare, and you will see more of the roadway.
Some vehicles have fog lamps that may be used in combination with low beams. Fog lamps will illuminate road edges and pavement markings, making it easier to stay in lane. They should only be used in heavy fog, rain, or snow – but remember to turn them off during normal driving conditions.
What Should I do if Another Driver Don’t Dim Their High Beam Headlights?
Sometimes an oncoming driver may forget to dim their headlights. The glare from oncoming headlights affects your vision and safe driving. If you look directly at the oncoming headlights you may be temporarily blinded, and it will take some time for your eyes to adjust again.
In general, drivers need more time to recover from glare as they age. Some medical conditions, like cataracts and diabetic retinopathy, also affects the time it takes to recover from glare. Read more: Blinded by the Light
If you meet a vehicle with high beam headlights:
Make sure you have dimmed your own headlights.
Slow down if you can’t see clearly ahead.
Don’t look directly into oncoming headlights.
Instead, shift your eyes toward the right edge of your lane or right edge of the roadway.
Watch the oncoming car from the corner of your eye.
Steer steadily until the oncoming vehicle has passed.
Do not try to “get back” at the other driver by keeping your high beams on.
It is often discussed if you should flash your high beams at the other driver or not.
In some states the law prohibits you from flashing your lights, so don’t!
When driving at normal speeds, we recommend that you concentrate on you own driving and don’t watch the oncoming headlights more than necessary. The other vehicle will soon have passed.
What Does the Law Say about High Beams?
The typical state law tells you to use low beams when you approach an oncoming vehicle or when you approach another vehicle from the rear. It also specifies the distance at which you must use lower beam lights.
Otherwise, the law typically say that you must use lights of sufficient intensity to reveal persons and vehicles at a safe distance in advance of your vehicle.
This means that if you drive faster in darkness, you must use high beams. At lower speeds or if there is sufficient light, you can use low beams.
Remember, if the law requires the use of headlights, like after sunset and before sunrise or in poor weather conditions, parking lights are not an acceptable replacement. Parking lights are for parked vehicles.
The typical state law:
Whenever a motor vehicle is being operated on a roadway or shoulder adjacent thereto during the times specified, the driver shall use a distribution of light, or composite beam, directed high enough and of sufficient intensity to reveal persons and vehicles at a safe distance in advance of the vehicle, subject to the following requirements and limitations:
1. Whenever the driver of a vehicle approaches an oncoming vehicle within 500 feet, such driver shall use a distribution of light, or composite beam, so aimed that the glaring rays are not projected into the eyes of the oncoming driver. The lowermost distribution of light or composite beam, shall be deemed to avoid glare at all times, regardless of road contour and loading.
2. Whenever the driver of a vehicle approaches another vehicle from the rear, within 300 feet, such driver shall use a distribution of light other than the uppermost distribution of light
When Should I Use Low Beam Headlights?
Remember, there are several situations when it is better to use low beam headlights!
You also know that the law requires you to dim high beam headlights when you meet a vehicle approaching from the opposite direction or when you approach another driver from behind. Read more about Low Beam Headlights
More reading: Why Night Driving Is So Dangerous – DMV Answers
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