Do you have a newer model car with headlights that fail to
safely illuminate the road? Do you
experience what appears to be a black curtain painted across the upper half of
your windshield? Do you find that you
can’t see road signs above a certain height or that when you turn into an unlit
driveway you cannot see where you are turning? Have you noticed that oncoming cars
frequently flash their lights at you and you’re momentarily blinded by an
intense light glare?
Many newer model cars today are being made with projector
headlights. These projector headlights are different than older models’ standard
headlights that had separate high beam and low beam light sources. Projector headlights are lit by a single filament
at one focus of an ellipsoidal reflector with a condenser lens in front of the
lamp. Between the reflector and the lens there is a shade that provides a cutoff
of all light above the center of the light bulb so that, theoretically, the low
beams will not blind on-coming drivers with the intense high beam. The shape and
sharpness of the cutoff is determined by the shade’s position in the optical
system and the shape of the shade’s edge. When the driver turns on the
projector’s high beam, the shade is lifted up and removed allowing all the
intense light to escape without any cutoff. The high beam from a projector headlight is a
very bright and produces a strong glare that can be blinding to oncoming drivers.
Many drivers are now noticing that one significant problem
with projector headlights on the low beam setting is that the cut-off line of the light moves when the car hits bumps in the road, accelerates, decelerates,
and when climbing or going down a slope in the road. Frequently, drivers now see what appears to
be oncoming cars with projector headlights “quickly flashing their brights;” however, in reality the
on-coming car has only hit a bump in the road surface causing the cut-off of light to
momentarily shift upward exposing a bright burst of the high intensity
light. This apparent flashing of the
high beams can be really annoying; however, a greater safety concern is that the
projector headlights’ cut-off of light moves when the car is going up or down a slope or
carrying a heavy load in the back of the vehicle. While going down a slope the projector’s cut-off of light shifts downward and the headlight’s beam distance is significantly diminished out in front of the car (headlights appear
to be driven down into the road surface).
Obviously, this creates a safety issue because the driver cannot see
pedestrians and animals out in front of the car to allow adequate and safe
stopping distances. Additionally, road
safety signs cannot be read on undulating roads because they are not illuminated
since the beam of light is being driven down on the down-slopes. Likewise, when a driver is
driving up a grade the projector’s cut-off of light shifts up further than it would on a
flat road and more of the high beam intense light is unintentionally directed
into the eyes of oncoming traffic. Both
of these two unintended consequences of projector headlights can lead to extremely dangerous driving conditions for drivers on Michigan roads and freeways.
If you are currently driving an automobile with projector
headlights, have you experience problems with the headlights? Please
let us know about your experiences and concerns.
