As the sun sets, traffic accidents and fatalities spike on American roadways. The government estimates that 2.8 million police-reported crashes, including
23,000 fatalities, occur annually in the United States at night or under poor visibility conditions. After the age of 45, vision tends to deteriorate and
nighttime driving can become more difficult. While 90 percent of a driver's reaction depends upon vision, driver error is also behind 90 percent of highway
Driving safety aim
With the current emphasis on active driving-safety measures to correct driver error, car headlight manufacturers are developing intelligent
lighting technologies that give drivers a brighter, longer and wider view of the road ahead while also limiting the glare for oncoming drivers.
Car headlights first made their appearance as acetylene gas lamps in 1885 and finally turned electric in 1905. In the 1990s, halogen and xenon lights made
the road brighter for nighttime drivers. Although glare complaints from oncoming drivers spiked with the new headlights, government studies found no
scientific basis for those complaints. Halogen headlights, now on 92 percent of the vehicles on the road, give a wider light and illumine greater
distances. Xenon lights, which are found on only 5 percent of vehicles on American roads, offer 70 percent more light than halogen
and deliver much wider light beams.
Adaptive front lighting system and sensors
Utilizing sensors that read the speed of the vehicle, steering, GPS information and weather, headlight manufacturers are developing automatic
systems that can deliver the best nighttime vision for any given road scenario. These intelligent lighting technologies – Adaptive Front Lighting System
(AFLS) – include side lights that are activated as needed and front headlights that are smarter than their predecessors. Each car headlight can be
individually aimed so that light can be trained on the driver's lane and not into the oncoming lane. Here’s how they work:
Low speed situations:
During residential driving, the system lowers the headlamp aim and increases the horizontal spread of the light to illuminate sidewalks, intersections,
pedestrians and curbs. This feature is automatically activated at vehicle speeds below 37 mph. AFLS reveals pedestrians or bicyclists far earlier than
standard lighting systems.
Sensors react to the speedometer and, as speed increases, raise the headlamp beam to illuminate a longer view of the road ahead and narrow the beam so
it does not intrude into the path of oncoming traffic. Sensors automatically activate this feature at speeds above 50 mph. These systems can also move
the headlamp beam to follow a curve by relying on sensors in the steering wheel, thus aiming the light in the direction that the vehicle is traveling.
This feature also keeps the light in the driver's lane and prevents blinding oncoming motorists.
In a left-hand turn, the left headlight will pivot up to 15 degrees (the right-hand
headlight remains pointed straight ahead) and in a right-hand turn, the right headlight will pivot up to 5 degrees (the left-hand headlight remains
pointed straight ahead).
In weather conditions such as fog or snow, the system lowers the headlamp aim to improve side lighting and narrows the forward beam to a sharp-pencil
beam, decreasing the glare. This feature can be activated with a manual control and through vehicle sensors.
These intelligent lighting systems were first available under various brand names in 2005, including the Acura RL, Audi A4, BMW X3, Infiniti M, Land Rover
Discovery, Lexus LS 430 and RX 330, MINI Cooper, Porsche Cayenne and Volvo S40 and V50.
Night driving safety tips
If you are going to rely on standard headlights for the time being, the Motor Vehicle Lighting Council offers these tips for nighttime driving
Use your lights courteously.
When on the road, turn your car headlights on one hour before sunset to make it easier for other drivers to see you in twilight, and keep your car
headlights on at least one hour after sunrise. In fog, use only your low beam headlights; high beams reduce your own ability to see and may temporarily
blind other drivers. If your vehicle is equipped with fog lamps, use them with your low beams only when there is fog or inclement weather.
Instead of looking at oncoming headlights, look toward the right side of the road and watch the white line marking the outside edge of the traffic lane.
When headlights from vehicles following you reflect in your rearview mirror, use the "day-night" feature on the mirror (if equipped) or adjust your mirror
to cut out as much of the light as possible.
Adjust your vehicle's interior lighting
If streetlights cause a lot of glare, dim your dashboard lights and use your sun visor. Avoid using any other light inside your vehicle.
Keep all windows and headlights clean.
Dirty windows can increase glare, making it more difficult to see, while dirty headlights can reduce efficiency by as much as 90 percent. Be sure to clean
the inside and outside of your windshield and your headlights.
Increase your following distance.
Increasing your distance by four to five seconds can make it easier to spot potential problems on and along the roadway and give you more time to respond.
In addition, proper lighting will enable you to react quicker and stop at a safe distance from the vehicle in front of you.
Use vehicle mirrors to your advantage.
Exterior mirrors that are properly aligned not only reduce blind spots but also reduce glare from vehicles behind you. The outside rearview mirrors should
be adjusted so that the bodywork of the vehicle is just outside of the driver's view.