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 |  |  | | | | Light Roads Ahead - Smart Headlamps Could Reduce Fatalities | | By Cathy Nikkel/autoMedia.com | |
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 45 years of age, everyone's vision begins to
deteriorate and nighttime driving becomes more difficult. Two statistics
underline the hazards of nighttime driving: 90 percent of a driver's reaction
depends upon vision, and driver error is behind 90 percent of highway
fatalities.
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| Safety Aim
With the current emphasis on active safety measures to correct driver error,
headlight manufacturers are developing intelligent lighting technologies that
give drivers a brighter, longer, wider view of the road ahead while, at the
same time, limiting the glare for oncoming drivers. 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. Glare complaints from oncoming drivers spiked with the new
headlights, but 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.
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
Systems (AFLS)—include side lights that are activated as needed as well as
front headlights that are smarter than their predecessors. Each headlight can
be individually aimed so that light can be trained on the driver's lane and
not into the oncoming lane.
In low speed situations, like 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.
On the highway, 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 relying on sensors
in the steering wheel and 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 15º (the right-hand
headlight remains pointed straight ahead) and in a right-hand turn, the right
headlight will pivot up to 5º (the left-hand headlight remains pointed
straight ahead). In bad weather 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 as well as through vehicle sensors.
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