is quite a history behind the modern day LED
police lightbar and emergency vehicle lights. Check out the
overview that was taken from Wikipedia regarding emergency vehicle
lighting. If you would like to view the entire article scroll
to the bottom of the page and click on the link. We plan to add
other interesting info pertaining to police, fire and EMS vehicle
safety. Email us if you know of any articles, studies or any other
pertinent information regarding emergency
vehicle lighting, light bars and beacons are terms referring to
devices designed to make an official vehicle easily identifiable.
Emergency vehicle lighting products are fitted to nearly every
emergency vehicle and most utility vehicles for the purpose of
alerting other vehicles and pedestrians of emergency situations
or other road hazards.
an emergency vehicle has the light bar flashing, it signals to
drivers and pedestrians that there is an emergency taking place
and that every driver needs to make their best attempt to clear
the road so that the emergency vehicle can pass safely. When the
lights are flashing, it may impose a sense of concern in many
drivers which is why many jurisdictions either ban or frown upon
the use of emergency lights in non-emergency situations. There
are some exceptions however. Police, many times, turn on their
emergency lights to protect a driver pulled over for a malfunction
in their vehicle or a flat tire. Firefighters may activate their
lights when pulling into the station to warn drivers of the engine's
are three main types of emergency vehicle lighting products: single
rotating or flashing beacons, larger car roof-sized lightbars,
and dashboard or interior lights. Both are effective at drawing
attention to a vehicle, but since their inception full-size light
bars have increasingly displaced single beacons.
their introduction in the 1940s, single
beacons have become widely accepted as a means of attracting
attention to one's vehicle. Although the use of a single beacon
in law enforcement has dropped since the introduction of light
bars, the single beacon is still used by some police departments
because of their lower cost, lower air resistance figures, and
in some cases simply due to tradition. One agency that continues
to employ a traditional single beacon on their patrol cars is
the Michigan State Police. Single beacons may also be seen as
secondary lights on a vehicle with a full light bar, either mounted
on the vehicles top or inside the vehicle, facing out the windshield
or rear window. Beacons are also commonly used on utility and
construction vehicles when a full-sized lightbar is ill-suited
or impossible to attach to the vehicle.
lights usually contain one or several lamps (commonly called
light bulbs) around which a curved mirror is spun, creating a
rotating beam of light. To protect the workings of the beacon,
a plastic dome covers the assembly. These domes usually come in
solid colors, but in some cases the front and back halves of the
dome are different colors. Other beacons use a clear dome with
colored lamps or reflectors inside. Especially in the last case,
these rotating beacons have been nicknamed "gumball machines".
beacons are now more often available as an omnidirectional strobe
light with a translucent dome. Some smaller and low-cost models,
however, are simply a flashing halogen bulb. LEDs are also used
to light some omnidirectional beacons.
single beacon is also available with a magnetic mount for situations
where permanent mounting is impractical. This can apply to detectives,
volunteer firefighters, or managers at freight yards who get a
company car but need an amber light for safety. These magnetic-mount
beacons are often round or teardrop shaped, and are often referred
to as "Kojak" lights after the popular 1970s TV series
that used one.
as the introduction of the single beacon was a great leap forward
in vehicle visual warning devices, the practice of using multiple
beacons (and thus multiple colors) was a natural progression.
In order to utilize two single beacons it became necessary to
install a bar across the roof to establish a level platform, and
then attach the beacons to this bar, often with a siren speaker
and/or "lollipop" lights between the beacons. This was
the origin of the term "light bar".
very earliest light bars appeared in the 1960s and were generally
custom-built by the agency using them. This was accomplished by
fabricating a bar to attach to the vehicle's roof, and then attaching
individual components (beacons, lollipops, speakers, oscillating
lights, etc.) to the bar. The beacon manufacturers quickly caught
on and began producing off-the-shelf complete "light bars".
next progression from the individual component design was to integrate
the elements of the lightbar into a single contiguous unit. The
colored dome over the beacon was extended toward the center of
the bar to accommodate fixed beam lights (in place of lollipops),
or one or more mirrors to enhance the flash pattern of the beacon.
An enclosure for the siren speaker bridged the gap between the
beacon lenses and resulted in the first true contemporary lightbar
lightbars combine various elements deemed worthwhile for the
specific applications they are applied to. These elements may
include: halogen/incandescent rotating lights with or without
accompanying mirrors, strobe lights, LED panels, two-tiered (above/below)
lights, fixed-beam "takedown" flashing lights, side-facing
"alley" spotlights, directional traffic advisory arrows,
siren speakers, and more. Several manufacturers have incorporated
programmable flash patterns into their lightbars. Some lightbar
variations are specialized to meet certain desires of the agency
utilizing them, such as those in a "V" shape design
which presents additional flash-power to the side of the vehicle,
and those designed to hug the roof of a vehicle to minimize air
resistance and/or present a lower profile for "stealth"
purposes. The modern trend of locating sirens and other audible
warning devices at the front of emergency vehicle has also resulted
in almost all lightbar models being offered in an "all-light"
configuration, with continuous lighting options available across
the entire width of the lightbar.
of emergency lights are used in the interior of a vehicle, generally
on the dashboard, visor area, or rear deck. These are available
in a variety of form factors, ranging from flat LED panels under
the sun visors, to halogen or strobe lights mounted on the rear
deck, to "cherry" or oscillating "teardrop"
lights mounted on the dash to interior lightbars. These may be
permanently mounted and wired into the vehicle's electrical system,
or they may be temporarily mounted and plug into the vehcle's
aerodynamic properties of light bars can be important for police
applications, as fuel efficiency and drag are concerns in patrol
and pursuit. Because of this, some police cars do not have roof
mounted lightbars. These "slick-top" cars mount their
emergency lights within the cruiser, generally around the visor
area, dashboard, or rear deck. Some slick-top cars are fitted
with lightbars that are built into the leading or trailing edge
of the roof, covering the extreme top of the front and/or rear
windshields. Slick-top police cars are also noteworthy in that
their silhouette lacks the shape of a lightbar or beacon, resembling
that of a civilian vehicle and making the car harder to identify
as a police vehicle. Because of these visual advantages, these
vehicles are often referred to as "stealth" vehicles
as opposed to their "marked" counterparts.
emergency vehicles have alternately flashing "wig-wag"
headlights, or have hideaway strobes within their headlights,
turn signals, and backup lights. These such setups allow integration
of modified OEM equipment and other lighting products.
lights within a lightbar may be halogen, strobe, or LED. Halogen
bulbs may be stationary steady or flashing lights, or they may
rotate within the lightbar, similarly to the "gumball"
lights can put out 1.5 million candle power for roughly 250 microseconds,
while lightbars using halogen bulbs can put out a constant 50,000
to 70,000 candle power.
lightbars are becoming very popular among many emergency agencies
for several reasons. The solid-state LEDs are very efficient and
draw less current from the car's battery. Their fast on/off transition
time enables attention-grabbing pulses. They have no moving parts
and are rated for up to 100,000 hours of use reducing downtime
for departments. Finally, LED lightbars can be made very thin
to offer less wind resistance.
people interpret the color of a lightbar to denote the type of
vehicle or situation, but the relationship between color and service
varies by jurisdiction. In North America the usual emergency colors
are red and blue, with blue reserved for police in many jurisdictions.
In western Europe the emergency color tends to be only blue, with
amber as a warning color for construction equipment etc. In eastern
Europe emergency vehicles use blue, or a combination of blue and
red. In Asia the usual emergency color is red.
has shown when flashing lights, twice the amount of blue light
energy is needed in daylight to be perceived as bright as red.
At night, the situation is reversed. Blue is specific to emergency
vehicles only, while red is very common in traffic, in traffic
lights, brake lights etc.
Emergency vehicle lighting. (2007, August 24). In Wikipedia, The
Free Encyclopedia. Retrieved 04:23, August 24, 2007, from http://en.wikipedia.org/w/index.php?title=Emergency_vehicle_lighting&oldid=153284874