Emergency vehicle lighting
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2008-07-16T18:12:27Z
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[[Image:Rtwnef Ambulance Rettungsdienst Germany.jpg|thumb|right|German emergency vehicles with all blue lights flashing]]
'''Emergency vehicle lighting''' refers to any of several visual warning devices, which may be known as light bars or beacons, fitted to a vehicle and used when the driver wishes to convey to other road users the urgency of their journey, to provide additional warning of a hazard when stationary, or in the case of law enforcement as a means of signaling the driver to stop for interaction with an officer. They are often used along with [[Siren (noisemaker)|sirens]] in order to maximize their effectiveness. In many jurisdictions, the use of these lights may afford the user specific legal powers, and may place requirements on other road users to behave differently, such as compelling them to pull to the side of the road and yield right of way so the emergency vehicle may proceed through at maximum speed.
==Purpose==
Emergency vehicle lighting is generally used to clear the right of way or to warn oncoming motorists of potential hazards, such as a vehicle that is stopped or moving slower than the rate of traffic. It may also be used to provide specific directions to motorists, such as a command to pull over. Some vehicles incorporate a small arrow board or even a text matrix display to direct traffic.
The use of emergency beacons is restricted by law in many jurisdictions only for responding to an emergency, initiating a traffic stop, bona fide training exercises, or when a specific hazard exists in the road.
==Optical types==
The optical and mechanical characteristics of the lights used can have a significant effect on the look of the vehicle and how readily it gains attention in emergencies.
===Rotating light===
[[Image:Composite green beacon photo.jpg|thumb|right|'''The parts and workings of a rotating light''': '''Top''' The assembled beacon, including an optional mirror to be used when the beacon is placed in the windshield or rear window. '''Center''' The beacon, with the mirror removed. '''Bottom left and right''' The green dome of the beacon has been removed to show its electric motor]]
These revolving lights may contain a single bulb around which a curved mirror is spun, creating a rotating beam of light, which appears to flash when viewed from a stationary position. Larger rotating lights may contain 2 or 4 modular or [[sealed beam|sealed-beam]] lamps which rotate as an assembly.
To protect the workings of the beacon, a plastic dome often 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 lenses on each lamp. Especially in the last case, these rotating beacons are sometimes referred to as "[[gumball machine]]s".
Rotating lights often use a [[Halogen lamp|quartz-halogen]] or conventional [[Incandescent light bulb|incandescent]] bulb, though some rotating beacons are now made with LEDs rather than bulbs.<ref>e.g. [http://www.aps-supply.com/product_details.php?itemid=540 Preco's 7600 series]</ref>
Rotating lights may be used in lightbars as well as in single beacons. In an enclosed lightbar, generally 'V'- or diamond-shaped mirrors are provided between the lamps to give the effect of multiple flashing lights.
===Strobe lights===
Some emergency lighting is based on [[strobe light]]s similar to those used in flash photography. These [[xenon flash lamp]]s put out a very brief but very bright flash by ionizing and then discharging a large current through the gas. The light produced has a somewhat bluish [[emission spectrum]], which makes red lightbars glow a fuchsia-pink color when lit.
===LED lighting===
[[Image:I-35W-collapse-police-Minneapolis-20070801.jpg|thumb|left|Police cars sit at the base of the [[I-35W Mississippi River bridge|I-35W bridge collapse]]. The lightbars mounted on the cars are LED-based.]]
LED-based lighting is becoming very popular in the emergency services for several reasons. [[Light-emitting diode]]s are small, completely solid state, very power-efficient, and have no filaments to burn out.
Whether as lightbars or single beacons, LED-based lights typically use a clear, colorless dome because the light color is an intrinsic property of the diodes themselves. LED-based lightbars can be made very thin to limit wind resistance, or made very flat and used in novel applications, for example to flip up under a sun visor.
LED lights are often used in a mode similar to conventional strobe lights, however they can be programmed with a wider variety of flash patterns because of their ability to be switched directly by electronics, as opposed to discharging a capacitor through a gas-filled tube.
===Information matrix signs===
Some emergency vehicles use signs made up of a large number of light sources (usually LEDs), which can be programmed to display messages to other road users. This can be used to request other vehicles to pull over, indicate a special instruction, or just to display the name of the operating service (e.g. 'Police')
==Mounting types==
Emergency lighting may be fitted to several places on a vehicle, depending on the degree of conspicuity required. Beacons and lightbars are often mounted on the roof for high visibility, while other lights may be mounted on the bodywork, in the grill, or in the interior of the vehicle. As well, the vehicle's stock lighting may be modified to add flashing and strobe effects.
===<div id="beacon_anchor">Roof-mounted single beacon</div>===
[[Image:MSPcar.jpg|thumb|left|A Michigan State Police cruiser with a single red beacon and hood fin]]
Since their introduction in the 1940s, rotating beacons have become widely accepted as a means of attracting attention to one's vehicle. Although the use of the single beacon in law enforcement has dropped since the introduction of light bars, they are still used by some police departments because of their lower cost and in some cases simply due to tradition. One agency that continues to employ a traditional rotating beacon on their patrol cars, in a custom hue of red, is the [[Michigan State Police]]. Beacons are also commonly used on construction equipment when a full-sized lightbar would be unnecessary or impractical to attach to the vehicle.
While many single beacons use rotating lamps or mirrors, others use strobe lights under a translucent dome to provide an omnidirectional flash. Some smaller and low-cost beacons of the latter type, however, are simply a blinking incandescent bulb. LEDs are also used to light some omnidirectional beacons.
The single beacon is also available with a magnetic mount for situations where permanent mounting is impractical. Examples of such situations would be [[detective]]s in unmarked vehicles, [[volunteer firefighter]]s, or managers at [[freight]] yards who use an amber light for safety. These "mag-mount" beacons are often round or teardrop-shaped, and are often referred to as "[[Kojak]]" lights after the popular 1970s TV detective who used one.
===Lightbar===
[[Image:Lightbar close-up to see mechanism.jpg|thumb|left|Close up of an older light bar: this light bar has a clear dome under which two rotating lights can be seen in this view. The rotating light on the right is fitted with an additional red lens, while the left light will give off unfiltered white light. A siren emitter is also built into this model.]]
Originally, this referred to a simple metal bar on the roof of the vehicle upon which agencies would mount two rotating beacons, as well as other components such as [[siren (noisemaker)#Vehicle-mounted|sirens]] and stationary "lollipop" lights. Soon the beacon manufacturers began producing off-the-shelf complete "light bars".
Later, the individual components of the lightbar were integrated into a single contiguous unit, with two elongated domes on either side of a siren enclosure. The extended domes allowed for more rotating beacons, additional mirrors, and fixed-beam lights toward the center to replace the "lollipops".
Lightbars may now contain fixed, rotating, strobe, or LED-based lights in various configurations and offering programmable flash patterns. They may include a second, lower, tier of lamps, such as clear halogen "takedown" lights towards the front to illuminate the vehicle being stopped, clear side-facing "alley" spotlights, additional amber or red towards the rear for scene protection, or directional traffic advisory arrows. The modern trend of relocating sirens to the front bumper of emergency vehicles has resulted in many lightbar models eliminating the siren in lieu of more lighting.
Some lightbar variations are specialized to meet certain desires of the agencies utilizing them, such as those using multiple rotating beacons in a "V" pattern to provide additional illumination to the sides of the vehicle, and those designed to hug the roof of a vehicle to minimize air resistance or present a lower profile for "stealth" purposes.
===Bodywork mounted===
[[Image:Beacon positions.jpg|thumb|right|Diagram showing potential mounting positions for internal, bodywork mounted and removable beacons on emergency vehicles]]
Some types of light can be mounted on to the outside of the vehicle (usually a permanent install) and these can be used to provide directional lighting in key areas, such as in front for clearing traffic, or to the rear for scene protection. They can also form part of the main lighting arrangement for subtly marked or unmarked vehicles. In this application, the operating service may choose to use lights with clear lenses so as to minimize the possibility of the lights being noticed when not on.
Common places to mount such beacons include on or in the grill of the vehicle and on the front of the rear view mirrors, where they can gain maximum visibility. In the U.K. many emergency vehicles have lights on the side of the bonnet, which helps to warn oncoming traffic when pulling out of junctions. These lights are often strobe or LED types, as they have the lowest profile for purposes of attachment.
===Vehicle integral===
Sometimes the existing lighting on a vehicle is modified to create warning beacons. In the case of [[wig-wag (automobile)|wig-wag]] lighting, this involves adding a device to alternately flash the high-beam headlights, or, in some countries, the rear fog lights. It can also involve drilling out other lights on the vehicle to add "hideaway" or "corner strobes".
===Interior mounted===
[[Image:Decklights.jpg|thumb|right|LED internal lights fitted to the rear of the headrests of a vehicle]]
A variety of emergency lights may be used in the interior of a vehicle, generally on the dashboard, visor area, or rear deck. Uses range from discreet or temporary lighting for unmarked vehicles and volunteer responders, to additional rear lighting on fully-marked vehicles, to a "slick-top" configuration not unlike a full lightbar set.
Interior lighting is 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. These may be permanently mounted and wired into the vehicle's electrical system, or they may be temporarily mounted and plug into the vehicle's cigarette lighter. They are often fitted with shields which direct the light through the window, but prevent reflections in to the cab.
[[Image:Dobbs Ferry PD cars 908 and 905, autumn 2006.jpg|thumb|left|The police car on the right is a slick-top or "stealth" vehicle, lacking the roof-mounted lightbar seen on the traditionally equipped car on the left.]]
The 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 periphery of the windshield or into the leading or trailing edge of the roof. Slick-top police cars also lack the silhouette of a lightbar or beacon, making the car harder to identify as a police vehicle. Because of these visual advantages, these vehicles are often referred to as "stealth" or "semi-marked" vehicles as opposed to their "marked" counterparts.
A key disadvantage of relying solely on internal lighting is the number of lights required to achieve true 360 degree visibility, with most lights usually concentrated front and rear. This can limit the application of vehicles for instances such as scene protection.
==Scientific research==
===Perception===
A study at Loughborough University in the United Kingdom showed that strobe lighting conveyed a greater sense of urgency to other road users, with the faster the flash the greater urgency, potentially helping to speed the emergency vehicle through traffic. It also concluded that factors such as flash pattern were important, with simultaneously flashing beacons attracting attention far quicker than alternately flashing versions, although this did increase discomfort glare. Unsurprisingly, attention was gained far quicker the higher the intensity of the light was, and the more beacons were present.
This same study compared different light colors for glare and detection time under both daylight and night conditions. While red and blue both compared favorably with amber for glare under various conditions, some contradictory findings were observed for detection time. When all colors were held at equal intensity, amber had the poorest detection time both daytime and night. But when the light source was held at constant intensity, the amber filters, which generally let the most light through, had the best detection time.<ref name=ICE>
{{cite conference
| first = Sharon
| last = Cook
| coauthors = Claire Quigley, Laurence Clift
| title = Motor vehicle and pedal cycle conspicuity: part 1- vehicle mounted warning beacons. Summary report.
| booktitle = DfT Report;PPAD 9/33/13
| publisher = Loughborough University
| date= March 2000
| url = http://hdl.handle.net/2134/520 <!-- http://dspace.lboro.ac.uk/dspace/handle/2134/520 -->
}}</ref>
===Potential hazards===
There may be a number of hazards to other road users related to the use of emergency beacons, and these effects should be mitigated as far as possible during vehicle design. These potential hazards include:
*[[Photosensitive epilepsy]] - This is an epileptic reaction to flashing lights in susceptible persons, which can range in severity from an unusual feeling or involuntary twitch to a generalized seizure. This epileptogenic response can be triggered by lights flashing in the frequency range of 10-20 Hz, regardless of color. While individual light sources used on emergency vehicles generally have much lower flash rates than this,<ref>
{{cite book
| last =Harding
| first =Graham F.A.
| coauthors =Peter M. Jeavons
| title =Photosensitive Epilepsy
| publisher =Mac Keith Press
| date= 1994
| location =London
| pages =p. 163
| isbn = 0-898683-02-6}}
"''neither car indicators nor flashing warning lights on emergency vehicles constitute a risk, as they are restricted to 2 f/s or less''"
</ref> the Loughborough study suggests that such possibilities be minimized. It also notes that emergency workers may report distraction and eyestrain unrelated to epilepsy from working under the lights.<ref>
Cook (2000:§5.3.1)</ref>
*[[Glare (vision)|Glare]] - A bright light source in a person's field of view can reduce their ability to see other objects. The effect may be exacerbated by rain, windshields, or eyeglasses. The study distinguished between "disability glare", where a driver may be temporarily blinded and unable to see hazards in the road, versus "discomfort glare", which is a more general effect from lights which may cause motorists to avert their eyes. The worst effects for disability glare occurred with amber beacons, strobe beacons, and especially bright lights.<ref name=ICE/>
*[[Phototaxis]] - This is the so called 'moth-to-flame' effect, where the hypothesis runs that some drivers may be so distracted by the beacons that they are 'drawn' to them. The Loughborough study, referencing the February 1998 issue of the U.S. trade journal ''Tow Times,'' asserts that there was a lawsuit in the U.S. where a tow operator was found liable for an accident for this reason, though the study authors were unable to locate any supporting scientific research.<ref>
{{cite conference
| first = Sharon
| last = Cook
| coauthors = Claire Quigley, Laurence Clift
| title = Motor vehicle and pedal cycle conspicuity - part 3: vehicle mounted warning beacons. Final report.
| booktitle = DfT Report;PPAD 9/33/13
| pages = p. 98
| publisher = Loughborough University
| date= June 1999
| url = http://hdl.handle.net/2134/527 <!-- http://dspace.lboro.ac.uk/dspace/handle/2134/527 -->
}}</ref>
==Usage by country==
[[Image:Rtwnef Ambulance Rettungsdienst Germany.jpg|thumb|right|German emergency vehicles (all blue beacons).]]
The color of a vehicle's emergency lights is useful to denote the type of vehicle or situation, but the relationship between color and service varies widely by jurisdiction. In North America the usual emergency colors are red and blue, with blue generally reserved for police in many jurisdictions and red reserved for fire departments and emergeny medical services. 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.
By far the most common colors for the core emergency services to use are blue and red, and there are some arguments for using both. One study found that for flashing lights, red was more easily perceived in daylight, and blue at night. Furthermore, red has advantages in haze and fog, while blue stands out against traffic at night.<ref>{{cite conference| first = Lt. James D. | last = Wells, Jr.|title = Florida Highway Patrol: Emergency Lighting Research & Prototype Evaluation | booktitle = International Association of Chiefs of Police | pages = pp. 5, 8 | date= March 2004 | url = http://www.theiacp.org/div_sec_com/Committees/Less/FHPevaluation.pdf }}</ref> On the other hand, a different study found that red had the quickest detection times at night.<ref>Cook (2000:§5.1.1)</ref>
===Argentina===
Argentina uses blue for police, red with some blue for fire, green for ambulances, and amber for utility vehicles.
===Australia===
In Australia, colors are generally regulated at the state level, but there are some commonalities:
*'''Red''' signifies a risk-to-life situation,<ref> [http://www.rta.nsw.gov.au/registration/downloads/vsi/vsi08.pdf New South Wales Roads and Traffic Authority: Flashing lights and sirens]</ref> and is used by fire engines, ambulances, Mines Rescue, Red Cross blood/organ transport, and [[State Emergency Service]] vehicles in most states. Until recently some states used only red on fire engines and ambulances.
*'''Amber''' lights are used by tow trucks and most other utility vehicles.
*'''Green''' lights are used to denote a stationary command vehicle.
*'''Blue''' lights are reserved for emergency vehicles in general, such as police, fire, ambulance, and traffic commanders.
*'''Magenta''' lights are used by [[council ranger]]s<ref>A council ranger is a type of peace officer found in Australia who enforces municipal ordinances, and has limited police powers.</ref> (except in Western Australia where they use amber <ref>[http://www.dpi.wa.gov.au/mediaFiles/lic_vsb13.pdf Western Australia DPI: Warning Lamps]</ref>) and state trucking inspectors.
*'''White''' is used on most newer emergency vehicles, both as an extra color on lightbars and in the form of 'wig-wag' headlights.
===Canada===
Generally, red is used for emergency vehicles, amber for construction and utility vehicles, and green for volunteer firefighters in some provinces. Blue is used, along with red, for police, as well as for snow removal vehicles in some provinces.
Police now use both red and blue in all provinces, now including Ontario,<ref>[http://ogov.newswire.ca/ontario/GPOE/2007/05/29/c6377.html?lmatch=&lang=_e.html McGuinty Government Continues To Keep Families Safe On Ontario's Roads]</ref><ref>
{{cite news
| last =Cairns
| first =Alan
| title =Roof lights changing from white to blue
| publisher =The Globe and Mail
| date =2007-04-13
| url =http://www.theglobeandmail.com/servlet/story/LAC.20070413.LIGHTS13/TPStory/TPNational/Ontario/
}}
</ref> where the color blue had been reserved for snowplows until recently. Fire department vehicles have also started to use red and blue lights in Ontario.
Some provinces restrict municipal peace officers (the exact title varies by province) to a different color; for instance red-only in Quebec, and amber in Ontario. However Ontario does permit certain types of provincial enforcement officers, such as [[Ontario Ministry of Transportation|Ministry of Transportation]], red lights. It is "gray issue" whether University Constables are legally permitted to use red lights on their patrol vehicles in Ontario due to the wording in the Highway Traffic Act; regardless, most vehicles used by University Constables do use red or red and blue lights.
In some provinces, green may indicate a volunteer firefighter's or medical responder's private vehicle.<ref>[http://www.e-laws.gov.on.ca/html/regs/english/elaws_regs_070484_e.htm Ontario Regulation 484/07: Lamps — use of flashing red or green lights]</ref><ref name="alberta">[http://www.canlii.org/ab/laws/regu/1997r.155/20030225/whole.html Alberta Highway Traffic Regulation 155/97]</ref> In addition to the use of optional green lights, volunteer firefighters often receive special licence plate size markings (red letters on a yellow background) to be displayed in place of a front licence plate, or in the window of said vehicle.
Utility vehicles generally use amber. Ontario and Newfoundland use blue lights for snowplows, while Alberta uses amber and red for snowplows, and has a public awareness campaign advising motorists that "flashing amber and red means snowplow ahead".<ref>[http://www.infratrans.gov.ab.ca/INFTRA_Content/docType45/Production/dhpage130.htm Alberta Infrastructure and Transportation - Snowplows]</ref> Alberta also allows red lights on certain classes of utility vehicles, such as natural gas utilities which may need to disconnect a gas line in an emergency.<ref name="alberta" />
While funeral vehicles may also use amber, more recently some funeral homes in Ontario have begun using purple lights for identification.<ref>
{{cite web
| last =McKenzie
| first =Grant
| title =How Safe are Funeral Processions?
| publisher =TheFuneralDirectory.com
| date =July 2000 <!-- Date comes from parent page http://www.thefuneraldirectory.com/griefarchives.html -->
| url =http://www.thefuneraldirectory.com/procession.html
}}
</ref> Often as a courtesy motorists yield to funeral processions, however they are not required to by law.
* '''Red and Blue''': police; and other "non-police" law enforcement in the provinces of AB, BC, SK, MB, NB, NS, PEI, NL, and the territories of YK, NWT, and NU. Fire department in ON.
* '''Red''': fire department; and other "non-police" law enforcement in the provinces of BC, ON, and QC.
* '''Red and White''': EMS; and the British Columbia Sheriff Office
* '''Blue''': snow plows, municipal and private contractors
* '''Amber''': construction and utility; funeral homes
* '''Purple''': funeral homes - Ontario
* '''Green''': emergency service volunteers
(Other "non-police" law enforcement means entities such as Conservation Officer, Ministry/Dept. of Transportation Enforcement Officers, University Constables, Community Peace Officers, and in some cases Municipal By-law Enforcement Officers and Fuel Tax Enforcement Officers)
===Europe===
In most of Europe emergency vehicles overwhelmingly use blue lights. However, it is a darker specification blue than used in other parts of the world. Swedish ambulances and fire engines often use white along with the dark "euro" blue to improve visibility during daylight hours.
German police lightbars often have "POLIZEI" written in white over the dome, and usually incorporate an [[LED]] text display that can read, in mirrored writing if towards the front, "BITTE FOLGEN" ("please follow"), to signal drivers to pull over. British police lightbars use the word "STOP".
{{Commonscat|Police cars by country}}
Red lights are not as common in Europe, though they are used in some countries where red has a specific meaning. Police in Finland, Estonia and Sweden use a forward-facing red light to indicate that a driver must pull over and stop. Germany and Sweden also use red on fire vehicles to designate the command post; in other countries a single green beacon sometimes designates the command post. Greece uses red on fire engines, and red along with blue on police vehicles. In Poland, red is used on some police and military vehicles to show that it leads a convoy. Until recently the National Police in Slovakia used only red lights, they have recently started using red and blue lights; Municipal and Military Police used blue lights in Slovakia.
Highway Taxation Enforcement Officers of the Dutch Ministry of Finance use red lightbars on their marked patrol vehicles in order to stop vehicles for enforcement purposes.
{{Commonscat|Fire engines}}
{{Commonscat|Ambulance}}
Amber lights generally designate nonemergency vehicles such as tow trucks or construction equipment.
====United Kingdom====
[[Image:Police Light-Bar.jpg|thumb|The Light Bar on top of a [[Tyne and Wear]] [[Police]] Car (England)]]
Usage of emergency vehicle lighting is restricted in the United Kingdom through the Road Vehicle Lighting Regulations 1989.<ref>{{cite web|title=Statutory Instrument 1989 No 1796: The Road Vehicles Lighting Regulations 1989|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_1.htm#end|publisher=Her Majesty's Stationery Office|date=1989|accessdate=2008-02-16}}</ref> It is illegal for any vehicle to show a flashing light on a vehicle (with the exception of the normal direction indicators and Anti lock brake indicators{{clarifyme}}), unless it is an emergency vehicle.<ref name=steady>{{cite web|title=RVLR: Lamps to Show a Steady light|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_3.htm#(Tii)i3lampshowsteadylight|publsiher=HMSO|accessdate-2008-12-16}}</ref>
The main colour for [[emergency service]] vehicles is blue, although there is also widespread use of flashing (white) headlights. The legal definition of an emergency vehicle limits the use of both methods to vehicles used for:<ref>{{cite web|title=RVLR Interpretation|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_2.htm#(Ti)3interpretation|pusliher=HMSO}}</ref>
*fire brigade, ambulance or police purposes (although no restriction exists here on private fire brigades or ambulance services)
*fire salvage
*Forestry commission or local authority when fighting fires
*Ministry of defence bomb disposal, mountain rescue, nuclear emergency or armament support
*Blood transfusion vehicles operating under the National Health Service Act (or Scottish equivalent)
*[[HM Coastguard]] and auxiliary
*British Coal Corporation (for mine rescue)
*[[Royal National Lifeboat Institution|RNLI]] vehicles launching lifeboats
*vehicles used for the purpose of conveying human tissue for transplant
*HM Revenue and Customs where investigating serious crime.<ref name=ammend2005/>
Blue flashing lights must only be lit at the scene of an emergency, or when the driver considers it desirable to indicate that the journey being undertaken is urgent.<ref name=blue>{{cite web|title=RVLR Requirements about using Blue warning beacons|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_4.htm#(Tiii)26requirementaboutusewarningbeacon}}</ref> Under these circumstances, may also claim legal exemptions from certain motoring regulations (although these are not specifically linked to the use of warning beacons), such as being able to treat a red traffic light as a [[give way sign]], ignoring the speed limit and passing the wrong side of a keep left/right sign. They may not, ignore "no entry" signs, drive the wrong way down a one-way street or cross a solid white line in the middle of the road (other than the same exceptions granted everyone else e.g. to pass a stationary vehicle). In reality some drivers will disobey other laws at their professional judgement but they do so without any automatic protection from the law.<ref>{{cite journal
| last = Picton
| first = Stephen
| title = Blues & Phews!
| journal = Driving magazine
| issue = July/August 2006
| pages = p. 15
| publisher = Safety House
| location = Croydon
| url = http://www.drivingmag.co.uk/2006website/julyaug/pdfs/1417.pdf
}}
"In fact he has only three legal exemptions, and these with caveats: he can exceed the speed limit, if proved necessary (but can still technically be prosecuted for dangerous driving or for driving without due care and attention); he can go through a red light, on the understanding that it is treated in the same way as a Give Way or Stop sign; and he can go to the wrong side of a keep left/right sign."
</ref>
With the exception of breaking the speed limit, which requires the driver to have completed or be performing a suitable training course<ref>{{cite web|title=Road Safety Act 2006: 19 - Exemptions from speed limits|url=http://www.opsi.gov.uk/acts/acts2006/ukpga_20060049_en_3#pb6-l1g19|publisher=HMSO}}</ref>, no qualification other than a [[driving license]] is legally required to use blue lights, though most organisations will insist that their drivers are trained in emergency driving techniques.
The common combination of blue flashing lights with two-tone sirens has led to '[[blues and twos]]' becoming a nickname for the core emergency services as a whole, as well as the title of a British documentary series depicting them.
Doctors on emergency calls are allowed a green courtesy light.<ref name=Colour>{{cite web|title=RVLR 1989 Colour of light shown by lamps and reflectors|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_3.htm#(Tii)iicolourlightshownlampreflector|date=1989|accessdate=2008-03-02}}</ref> Flashing red lights are not generally allowed on vehicles, though many emergency vehicles have rear-facing flashing red lights, which are used to signify that the vehicle is stationary. These are, however, specifically prohibited by the RVLR.<ref name=steady/><ref name=Colour/>
Checkered lights denote command and control vehicles - these are red and white for fire (one of the few situations where a forward-facing red light may be shown), blue and white for police and green and white for ambulance,<ref name=Colour/> and are often fitted in the middle of the light bar.
Amber lights grant no priority in traffic and exist purely to advertise the vehicle's presence. The RLVR specifies several classes of vehicles which may use amber lights, such as towing, highway maintenance, pilot vehicles escorting an oversize load, and vehicles unable to travel over 25 mph<ref name=ammend2005>{{cite web|publisher=HMSO|title=The Road Vehicles Lighting (Amendment) Regulations 2005|url=http://www.opsi.gov.uk/si/si2005/20052559.htm|date=2005|accessdate=2008-03-02}}</ref> and fitting these lights to other vehicles is technically illegal (although these beacons are widely fitted to vehicles as wide ranging as security and ambulances).
It should also be noted that UK legislation considers all lights, reflectors and reflective material to be lights, and all items resembling special warning beacons (of any colour) must be covered and not just disconnected (as this is a separate offence)<ref>{{cite web|title=RVLR 1989 Regulations governing the maintenance and use of lamps, reflectors, rear markings and devices|accessdate=2008-03-02|date=1989|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_4.htm#(Tiii)23maintenancelampreflectorrearmarkingdevice}}</ref> while on the public highway.<ref>{{cite web|title=RVLR 1989 Restrictions on fitting blue warning beacons, special warning lamps and similar devices|url=http://www.opsi.gov.uk/si/si1989/Uksi_19891796_en_3.htm#(Tii)i6restrictionfittingbluewarningbeaconspecialwarninglampsimilardevice|date=1989|accessdate=2008-03-02}}</ref> Similarly, no distinction is made between lights mounted on light bars and those mounted anywhere else on the vehicle (e.g. headlights, indicators, brake lights) - all are covered by the same regulations.
===Hong Kong===
Under HK Law, Chap 374G ''Road Traffic (Traffic Control) Regulations: Section 46 Giving way to animals, police vehicles, ambulances, etc,'' drivers must yield to vehicles who are sounding siren or flashing light bars.
*'''Red and Blue''': [[Hong Kong Police Force]]
*'''Red only''': [[Fire Services Department]] fire engines
*'''Blue only''': Ambulances, whether operated by [[Fire Services Department]], [[Auxiliary Medical Services]], or [[Hong Kong St. John Ambulance]], also [[Customs and Excise Department (Hong Kong)|Customs and Excise Department]]
*'''Amber only''': Utility vehicles, also [[Civil Aid Service]], and all vehicles in the air-side of the [[Hong Kong International Airport|airport]] (for pilots' visibility)
===Japan===
[[Image:Patrol car2.jpg|thumb|right|A Japanese police unit with a red light bar]]
Red is the most used color on Japanese emergency vehicles, with the exception of the wig-wag headlights. The Japanese police uses light bars mounted on a raised platform or a mechanical raised platform to make them more visible over congested streets. Rotating light are the most commonly used. But some of the newer fire vehicles do have LED light bars installed. Vehicles with any other color light are security or engineers.
*'''Red:''' [http://en.wikipedia.org/wiki/Police_system_of_Japan Police Department], [http://en.wikipedia.org/wiki/Firefighting_worldwide#Japan Fire Department], and any other emergency vehicles.
*'''Amber:''' Engineer vehicles and [http://en.wikipedia.org/wiki/JH Japan Highway Public Corporation] vehicles.
*'''Blue:''' Security and City vehicles.
===New Zealand===
In New Zealand, the colors used on lightbars and beacons are defined by the New Zealand Land Transport Safety Authority regulations.<ref>
[http://www.landtransport.govt.nz/rules/vehicle-lighting-2004.html Land Transport NZ: Vehicle Lighting 2004, Rule 32005]</ref><ref>
[http://www.ltsa.govt.nz/road-user-safety/new-road-rules/summary-of-changes.html Land Transport NZ: 2004 summary]</ref>
*'''Blue''': The [[New Zealand Police]], as the national police force of New Zealand, are the only agency authorized for blue lighting. Police vehicles are usually equipped with red, blue, and white lights in the form of a lightbar and dashboard lights.
*'''Red''': Any vehicle defined as an emergency vehicle, including police, a recognized ambulance service, or the [[New Zealand Fire Service]], may display red beacons, with the option of white flashing lights facing forward only. Emergency vehicles, as well as pilot vehicles, are allowed the use of wig-wag headlights.
*'''Amber''': Amber lights may be operated by towing companies, traffic management agencies,<ref>In New Zealand, a traffic management agency provides civilian flaggers to direct traffic at road construction sites.</ref> or by other utility vehicles when necessary to warn other motorists of a hazard. Amber must also be fitted to oversize vehicles and their pilot vehicles.
*'''Purple''': Purple and amber lights must be fitted to pilot vehicles escorting an oversize vehicle.
*'''Green''': A vehicle operated by a registered medical practitioner, such as a doctor, nurse or midwife, may be fitted with a single green beacon.
Volunteers in general are afforded no special privileges and cannot use flashing lights or sirens in order to navigate traffic. However, volunteer [[Fire Police]] members who respond to calls in their own private vehicles may be authorized by their unit or brigade to display a red beacon, for reasons of safety and identification. However, these lights may only be fitted and operational while stationary at an emergency scene, not while mobile in traffic.
===South Korea===
*'''police''': Police cars use a six-bulb strobe based lightbar,red and blue. Motorcycles use either red or blue lights(rotating).
*'''ambulances''': Ambulances have many different colors. Private hospital ambulances use green and red while government-operated ambulances use red and white or green and white.
*'''fire department''': Fire engines are fitted with red and white LED/strobe lights.
===United States===
[[Image:Luminapolice.jpg|thumb|A [[security officer]]'s personal vehicle from the state of Georgia, with a green lightbar on its roof.]]
In the United States, colors are generally regulated at the state level, but there are some commonalities.
*'''Red''' almost always denotes an emergency vehicle if the lights are facing forward.
*[[Amber (color)|'''Amber''']] or '''Yellow''' lights are often used by vehicles such as construction vehicles, tow trucks, funeral escorts, security patrol vehicles or other vehicles which may be stopped or moving slower than the flow of traffic. Amber is usually the most permissively regulated color.
*'''White''' is often used as an optional color on lightbars, though it may be restricted to emergency vehicles in some states. It is rarely used as the only color on a lightbar, though Arkansas, Rhode Island, New Hampshire, Florida, Michigan, Wisconsin, Maryland and Kentucky require flashing white beacons on school buses. Certain railroad-related machines, like fueling tankers or switching engines, may also use a flashing white light.
*'''Green''' on a fire chief's car or a mobile command post denotes the command vehicle on scene; this usage derives from the use of green flags in the [[Incident Command System]]. Green can also denote a volunteer firefighter or EMT's vehicle in some states. In some states, green is used by private security guards.
*'''Blue''' is reserved for law enforcement in some states, while in others it is used by volunteer firefighters and EMTs. In New Mexico, tow trucks have blue lights. Alaska, Arizona, Colorado, Minnesota, and Nebraska also use blue lights on snowplows.<ref>[http://www.codepublishing.com/AK/Sitka/Sitka11.html#11.13.04.100 Alaska Code §11.13.04.100: Flashing blue lights on vehicles]</ref><ref> {{cite journal
| last = Stidger
| first = Ruth W
| title = Safer Winter Maintenance
| journal = Better Roads Magazine
| issue = October 2003
| publisher = James Informational Media, Des Plaines
| url = http://obr.gcnpublishing.com/articles/oct03c.htm
}} </ref><ref>
[http://law.justia.com/nebraska/codes/s60index/s6006230000.html Nebraska Code § 60-6,230: Lights; rotating or flashing; colored lights; when permitted.]</ref>
*'''Purple''' is permitted in some states to denote a funeral vehicle.<ref> [http://www.arkansashighways.com/Info/Act300/2007/27/27-36-306.htm Arkansas Motor Vehicle and Traffic Laws § 27-36-306: Other nonemergency vehicles - Funeral processions]</ref><ref>
[http://www.flsenate.gov/statutes/index.cfm?App_mode=Display_Statute&URL=Ch0316/titl0316.htm Florida Statute 316.1974: Funeral procession right-of-way and liability.]</ref><ref>
[http://leg1.state.va.us/cgi-bin/legp504.exe?000+cod+46.2-1025 Code of Virginia §46.2-1025: Flashing amber, purple, or green warning lights.]</ref><ref>
[http://www.legis.state.wv.us/wvcode/17c/WVC%2017%20C-%2015%20%20-%20%2019%20%20.htm West Virginia Code §17C-15-19. Additional lighting equipment.]</ref>
====Police====
Police agencies may use red, blue, or both, depending on the state, along with white and amber as optional colors. Some police cars have an amber traffic-control stick, or "arrow stick", behind the lightbar to direct traffic left or right around the vehicle; these usually have 6 or 8 rear-facing lights that flash in sequence.
Unlike some countries that have a national or provincial police force, with only limited powers for local officers, most of the police in the United States are municipal or county officers, and they are not restricted to a different color, such as the council rangers of Australia or the municipal bylaw officers of Canada. However, most U.S. cities have a separate force for parking enforcement, and these generally use amber and not blue or red.
Some privately-operated [[special police]] are allowed to display the same colors as regular police, generally, if they receive their special police authority at the state level. This can include railroad, university, hospital, and humane society police departments.
====Fire and EMS====
Fire and [[emergency medical services]] generally use red and white lights. Vehicles operated by fire departments, such as [[fire engines]] and [[heavy rescue]] vehicles, prominently use red, a color with strong cultural associations with the fire service, along with some white. Amber, and blue in some states, are also shown towards the rear. Many fire chiefs' cars have, in addition to the red lights, a single green beacon to indicate command post status. On the other hand, in Chicago and some nearby communities, fire vehicles show a green light on the right, or starboard, side, of the vehicle, reflecting nautical tradition.<ref>
{{cite journal
| title = Why does the Chicago Fire Department outfit their trucks and stations with green lights?
| journal = Hot Times newsletter
| publisher = Federal Signal Corporation
| location = University Park, IL
| date= June 2007
| url = http://www.fedsig.com/industry_solutions/fire_ems/hotTimes_news/archives/electronic/2007/6/?show=main}}
</ref>
Emergency medical vehicles, such as [[ambulance]]s and paramedic [[fly-car]]s, generally use white and red, with an amber light facing the rear. Some states have a specific rule authorizing light colors for EMS vehicles, while on the other hand some EMS vehicles "inherit" their light colors from the fire or police department they are operated by or contracted to, and may show blue lights.
The [[National Fire Protection Association]] publishes the [[NFPA 1901|NFPA-1901]] standards for fire vehicles,<ref> [http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=1901 NFPA 1901: Standard for Automotive Fire Apparatus]</ref> which specifies the degree of lighting on various parts of the vehicles, with some flexibility as to color. There is also a [[General Services Administration|GSA]] procurement specification for ambulances known as KKK-A-1822,<ref> [http://apps.fss.gsa.gov/vehiclestandards/index.cfm GSA Automotive: Federal Vehicles Standards]</ref> which many local authorities follow.
====Volunteer Personnel====
[[Image:NREMT-B1645045-truck2.JPG|thumb|right|A Volunteer [[Emergency medical technician|EMT]]'s personal vehicle with lights off]]
[[Image:NREMT-B1645045-truck1.jpg|thumb|right|The above EMT's vehicle at night with lights flashing]]
Many U.S. states allow volunteer fire and [[Emergency Medical Services|EMS]] personnel to place emergency warning lights in their personal vehicles for use when responding to emergencies. The laws vary greatly by state. For instance, Virginia state law allows emergency personnel to equip one private vehicle ''"with no more than two flashing or steady-burning red or red and white combination warning lights"''.<ref>[http://uclue.com/?xq=777 Virginia Personal Emergency Vehicle Lights]</ref>
The degree of lighting is mandated by law and also by local custom in most areas, and can vary from a single rotating light on the dashboard or roof, to a setup much like modern police cruisers. Some states also allow volunteer use of sirens and air horns to clear the right of way.
In some states, volunteers are allowed to use the normal red lights, while in other states volunteers must use some other color, usually blue or green. In the latter case, the lights are used as a courtesy to "request" the right of way and generally do not mandate pulling over. Some states, such as New Jersey and Pennsylvania, limit volunteer use of red lights to chiefs and captains of squads.
Separate colors may be used for fire versus EMS volunteers. In Connecticut, Indiana, and New York, volunteer firefighters use blue while volunteer EMTs use green. New York also certifies some volunteer EMTs to use red lights and sirens provided their vehicles carry certain equipment;<ref>
[http://www.health.state.ny.us/nysdoh/ems/policy/01-01.htm NYS Department of Health: Authorizing Private Vehicles as EASV's (Use of Red Lights & Sirens)]</ref> this is often used by [[Hatzolah]] volunteers in the NYC area.
The conflicting color assignments can create issues for volunteers who drive their vehicles out of state. While some authorities may be satisfied with covering the lights with an "Out Of Service" tarp, compliance may be more difficult in other jurisdictions. For example, Arkansas bars civilian possession of blue lights on or in a vehicle unless sealed in the manufacturer's original package.<ref>
[http://www.arkansashighways.com/Info/Act300/2007/27/27-36-301.htm Arkansas Motor Vehicle and Traffic Laws § 27-36-301: Violations]</ref>
The confusion generated by the different colors in each state can also cause problems for drivers who travel into others states. One color in their state may mean firefighter or EMT when in another state it may mean police, obviously causing problems.
====Utility Vehicles====
Yellow lights have become popular in the civilian arena as a way of drawing attention to a vehicle involved in non-emergency work. Most phone and cable companies, towing services, and certain types of construction equipment mount some type of lightbar; additionally, several local and state vehicles involved in maintenance work for roads, gas and water pipes, electric services, and so forth utilize yellow lights for a higher degree of visibility. In [[Detroit, Michigan]], [[Angel's Night]] volunteers will patrol neighborhoods with yellow lights to help deter vandalism during [[Devil's Night]] and [[Halloween]]. Typically these lights are the single beacon kind, although lightbars have been used for vehicles of this type, especially on wreckers/tow trucks.
In states that do not enforce specific rules about green, yellow or white lights, they are often used by entities like private security companies which may be ineligible to use blue or red lights but wish to distinguish themselves from utility vehicles. Security vehicles generally use their lights on private property and are generally not allowed a "courtesy" or "emergency" light on public roads. Some security companies have gone so far as equipping their vehicles with sirens.
====Optional colors====
Often while certain colors are customarily used by different services, there are other colors that are optionally used, such as amber and white. Sometimes this is done to satisfy particular regulations; for example, California requires a steady red light facing forward on every emergency vehicle.<ref> [http://www.dmv.ca.gov/pubs/vctop/d12/vc25259.htm CA Vehicle Code §25252: Warning Lamps on Authorized Emergency Vehicles]</ref><ref> Emergency vehicles in California generally show a flashing amber light to the rear as well.</ref><ref> {{cite web | last = Faugh | first = Robert J | title = Emergency Warning Lights & Parking Procedures | publisher = Firehouse.com | url = http://cms.firehouse.com/content/article/article.jsp?id=49922§ionId=15 }}</ref>
==See also==
* [[Automotive lighting]]
* [[Emergency vehicle equipment]]
* [[Whacker]] http://www.policeposers.com/whacker.php
==Notes==
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[[Category:Automotive technologies]]
[[Category:Emergency vehicles]]
[[Category:Law enforcement equipment]]
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