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A high pressure sodium vapor street lamp from Australia. The brown circular object under the light is a photocell.

A street light, lamp post, street lamp, light standard or lamp standard, is a raised source of light on the edge of a road, turned on or lit at a certain time every night. Modern lamps may also have light-sensitive photocells to turn them on at dusk and off at dawn, or activate automatically in dark weather. It is also not uncommon for street lights to be on posts which have wires strung between them, such as on telephone poles or utility poles. Image File history File links Gnome-globe. ... Image File history File links Metadata Size of this preview: 450 × 600 pixelsFull resolution (1704 × 2272 pixel, file size: 648 KB, MIME type: image/jpeg) A 250 watt high pressure sodium vapour street lamp. ... Image File history File links Metadata Size of this preview: 450 × 600 pixelsFull resolution (1704 × 2272 pixel, file size: 648 KB, MIME type: image/jpeg) A 250 watt high pressure sodium vapour street lamp. ... A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... A photoresistor is an electronic component whose resistance decreases with increasing incident light intensity. ... This article does not cite any references or sources. ... Mountain road with hairpin turns in the French Alps For other uses, see Road (disambiguation). ... A photoresistor is an electronic component whose resistance decreases with increasing incident light intensity. ... For the geological process, see Weathering or Erosion. ... A telegraph post, telegraph pole or telephone pole is a post or pole upon which telephone network equipment is situated. ... Pole carrying telephone, electricity and Cable TV equipment. ...

History of street lighting

Further information: History of street lighting in the United States

Before incandescent lamps, gas lighting was employed. The earliest lamps required that a lamplighter tour the town at dusk, lighting each of the lamps, but later designs employed ignition devices that would automatically strike the flame when the gas supply was activated. The earliest of such street lamps were built in the Arab Empire.^[1] The use of street lighting was first recorded in London in 1417 when Sir Henry Barton, the mayor, ordered lanterns with lights to be hanged out on the winter evenings between Hallowtide and Candlemasse. ... Gas lighting is the process of burning piped natural gas or coal gas for illumination. ... A lamplighter, historically, was an employee of a town who lit gas streetlights, generally by means of a wick on a long pole. ... The Arab Empire at its greatest extent The Arab Empire usually refers to the following Caliphates: Rashidun Caliphate (632 - 661) Umayyad Caliphate (661 - 750) - Successor of the Rashidun Caliphate Umayyad Emirate in Islamic Spain (750 - 929) Umayyad Caliphate of Córdoba in Islamic Spain (929 - 1031) Abbasid Caliphate (750-1258...

A surviving arc light column on Cheyne Walk, Chelsea Embankment, London. (January 2006)

New and old style street lights

The first electric street lighting employed arc lamps, initially the 'Electric candle', 'Jablochoff candle' or 'Yablochkov candle' developed by the Russian Pavel Yablochkov in 1875. This was a carbon arc lamp employing alternating current, which ensured that the electrodes burnt down at the same rate. Yablochkov candles were first used to light the Grand Magasins de Louvre, Paris where 80 were deployed. Soon after, experimental arrays of arc lamps were used to light Holborn Viaduct and the Thames Embankment in London - the first electric street lighting in Britain. More than 4,000 were in use by 1881, though by then an improved differential arc lamp had been developed by Friederich von Hefner‑Alteneck of Siemens & Halske. The United States was swift in adopting arc lighting, and by 1890 over 130,000 were in operation in the US, commonly installed in exceptionally tall moonlight towers. Image File history File links Download high resolution version (592x800, 466 KB) Summary Arc light column, Cheyne Walk, Chelsea, London, by nothern side of Battersea Bridge. ... Image File history File links Download high resolution version (592x800, 466 KB) Summary Arc light column, Cheyne Walk, Chelsea, London, by nothern side of Battersea Bridge. ... Cheyne Walk (pronounced Chaynee) is the most historic street in Chelsea, a bit of picturesque old London. Most of the houses were built in the early eighteenth century. ... Chelsea Embankment is part of the Thames Embankment, a road and walkway along the north bank of the River Thames in central London. ... This article is about the capital of England and the United Kingdom. ... Image File history File links Size of this preview: 400 × 600 pixelsFull resolution (427 × 640 pixel, file size: 54 KB, MIME type: image/jpeg) New and old style street lights in Nashville, TN. (Photo by Oleg Volk) File historyClick on a date/time to view the file as it appeared... Image File history File links Size of this preview: 400 × 600 pixelsFull resolution (427 × 640 pixel, file size: 54 KB, MIME type: image/jpeg) New and old style street lights in Nashville, TN. (Photo by Oleg Volk) File historyClick on a date/time to view the file as it appeared... The 300,000-watt Plasma Arc Lamp in the Infrared Processing Center (IPC) at Oak Ridge National Laboratory An arc lamp is a device that produces light by the sparking (or arcing, from voltaic arc or electric arc) of a high current between two carbon rod electrodes. ... A Yablochkov candle (sometimes electric candle) is a type of electric carbon arc lamp, invented in 1876 by Pavel Yablochkov. ... Pavel Nikolayevich Yablochkov (Павел Николаевич Яблочков in Russian) (September 14/September 2 (O. S.), 1847 – March 31/March 19 (O.S.) 1894 ) was a Russian electrical engineer, the inventor... 1875 (MDCCCLXXV) was a common year starting on Friday (see link for calendar). ... This article is about the capital of France. ... The Holborn Viaduct is a bridge linking Holborn with Newgate Street in the City of London, passing over Farringdon Street. ... Victoria Embankment, London The Victoria Embankment, previously the Thames Embankment is a road and walkway along the north bank of the River Thames in London in the cities of Westminster and London. ... This article is about the capital of England and the United Kingdom. ... Year 1881 (MDCCCLXXXI) was a common year starting on Saturday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Thursday of the 12-day slower Julian calendar). ... The Siemens & Halske AG (or Siemens-Halske) were a German electrical engineering company that later became part of the Siemens AG. The Siemens & Halske AG was founded in 1897 when the former Telegraphen-Bauanstalt Siemens & Halske became a stock corporation. ... Year 1890 (MDCCCXC) was a common year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Monday of the Julian calendar). ... Moonlight tower in Austin, Texas. ...

Timişoara, in present-day Romania, was the first city in mainland Europe to have electric public lighting on the 12th of November 1884. 731 lamps were used. County Status County Capital Mayor Gheorghe Ciuhandu, Christian-Democratic Peoples Party, since 1996 Area 129. ... Year 1884 (MDCCCLXXXIV) was a leap year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Sunday of the 12-day-slower Julian calendar). ...

Arc lights had two major disadvantages. First, they emit an intense and harsh light which, although useful at industrial sites like dockyards, was discomforting in ordinary city streets. Second, they are maintenance intensive, as carbon electrodes burn away swiftly. With the development of cheap, reliable and bright incandescent light bulbs at the end of the 19th century, they passed out of use for street lighting, but remained in industrial use longer. Light bulb redirects here. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ...

A lamp post with six lamps

The internal components of a photoelectric control for a typical American streetlight

Incandescent lamps used for street lighting until the advent of high-intensity discharge lamps, were often operated as high-voltage series circuits. To avoid having the entire street go dark if a single lamp burned out, each street lamp was equipped with a film cutout, a small disk of insulating film that separated two contacts connected to the two wires leading to the lamp. If the lamp failed (an open circuit), the current through the string became zero, causing the entire voltage of the circuit (thousands of volts) to be imposed across the insulating film, penetrating it (see Ohm's law). In this way, the failed lamp was bypassed and illumination restored to the rest of the street. (This is the same principle used in Christmas tree lights.) The circuit usually contained an automatic device to regulate the voltage in the circuit, preventing the current from increasing as additional lamps burned out , preserving the life of the remaining lamps. When the failed lamp was replaced, a new piece of film was installed, once again separating the contacts in the cutout. This style of street lighting was recognizable by the large porcelain insulator that separated the lamp and reflector from the light's mounting arm. The insulator was necessary because the two contacts in the lamp's base may have operated at several thousands of volts above ground/earth. Image File history File linksMetadata Download high resolution version (1904x1408, 1314 KB) File links The following pages link to this file: Street light Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File linksMetadata Download high resolution version (1904x1408, 1314 KB) File links The following pages link to this file: Street light Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File links Size of this preview: 757 × 600 pixelsFull resolution (1161 × 920 pixel, file size: 98 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Photoresistor Street light ... Image File history File links Size of this preview: 757 × 600 pixelsFull resolution (1161 × 920 pixel, file size: 98 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Photoresistor Street light ... LDR The internal components of a photoelectric control for a typical American streetlight. ... This article or section does not adequately cite its references or sources. ... Open circuit can mean:- In electronics, where there is nothing connected to a load and no current can flow. ... In electricity, current refers to electric current, which is the flow of electric charge. ... A voltage source, V, drives an electric current, I , through resistor, R, the three quantities obeying Ohms law: V = IR Ohms law states that, in an electrical circuit, the current passing through a conductor between two points is proportional to the potential difference (i. ... Christmas lights (also sometimes called fairy lights, twinkle lights or holiday lights in the United States) are strands of electric lights used to decorate homes, public/commercial buildings and Christmas trees during the Christmas season. ... “Fine China” redirects here. ...

Today, street lighting commonly uses high-intensity discharge lamps, often HPS high pressure sodium lamps. Such lamps provide the greatest amount of Photopic illumination for the least consumption of electricity. However when Scotopic/Photopic light calculations are used, it can been seen how inappropriate HPS lamps are for night lighting. White light sources have been shown to double driver peripheral vision and increase driver brake reaction time at least 25%. When S/P light calculations are used HPS lamp performance needs to reduced by a minimum value of 75%. This is now a standard design criteria for Australian roads. 15 kW Xenon short-arc lamp used in IMAX projectors High-intensity discharge (HID) lamps include these types of electrical lamps: mercury vapor, metal halide (also HQI), high-pressure sodium (Son), low-pressure sodium (Sox) and less common, xenon short-arc lamps. ... A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ...

Disadvantages

The major criticisms of street lighting are that it can actually cause accidents if misused, and can cause light pollution. This time exposure photo of New York City shows sky glow, one form of light pollution. ...

Dangers of street lights

There are two optical phenomena that need to be recognized in street light installations.

• The loss of night vision because of the accommodation reflex of drivers' eyes is the greatest danger. As drivers emerge from an unlighted area into a pool of light from a street light their pupils quickly constrict to adjust to the brighter light, but as they leave the pool of light the dilation of their pupils to adjust to the dimmer light is much slower, so they are driving with impaired vision. As a person gets older the eye's recovery speed gets slower, so driving time and distance under impaired vision increases.

• Oncoming headlights are more visible against a black background than a grey one. The contrast creates greater awareness of the oncoming vehicle.

There are also physical dangers. Street light stanchions (poles) pose a collision risk to motorists. This can be reduced by designing them to break away when hit, protecting them by guardrails, or both. High winds or accumulated metal fatigue also occasionally topple street lights. Night-vision is seeing in the dark. ... Human eye The Accommodation Reflex is a reflex action of the eye, in response to focusing on a near object, then looking at distant object (and vice versa). ... The human eye The pupil is the central transparent area (showing as black). ... In materials science, fatigue is the progressive, localised, and permanent structural damage that occurs when a material is subjected to cyclic or fluctuating strains at nominal stresses that have maximum values less than (often much less than) the static yield strength of the material. ...

Light pollution

In urban areas light pollution can hide the stars and interfere with astronomy. In settings near astronomical telescopes and observatories, low pressure sodium lamps may be used. These lamps are advantageous over other lamps such as mercury and metal halide lamps because low pressure sodium lamps emit lower intensity, monochromatic light. Observatories can filter the sodium wavelength out of their observations and virtually eliminate the interference from nearby urban lighting. This time exposure photo of New York City shows sky glow, one form of light pollution. ... For other uses, see Astronomy (disambiguation). ... This article does not cite any references or sources. ... MolÄ—tai Astronomical Observatory An observatory is a location used for observing terrestrial and/or celestial events. ... For sodium in the diet, see Edible salt. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery Standard atomic weight 200. ... Metal halide lamps are similar to mercury vapor lamps, but instead of just mercury, they also contain all metals in the halide group of the periodic table (Hence the name). ... Something which is monochromatic has a single color. ... For other uses, see Wavelength (disambiguation). ...

The light pollution also disrupts the natural growing cycle of plants.

Safety

A street light in Singapore

A misconception is that installing street lights will automatically make streets safer and reduce crime, so political pressure can be a major factor in installation of street lights. Untrained officials often assume that if some is good, more must be better, and install the brightest lights possible. Misuse of street lights can cause accidents, and crime lighting is an entirely different type of lighting than used for automobile navigation.^{[citation needed]} Image File history File links Lamppost-singapore. ... Image File history File links Lamppost-singapore. ...

Purposes of street lights

There are three distinct main uses of street lights, each requiring different types of lights and placement. Incorrect misuse of the different types of lights can make the situation worse by compromising visibility or safety.

Beacon lights

A modest steady light at the intersection of two roads is an aid to navigation because it helps a driver see the location of a side road as he comes closer to it and he can adjust his braking and know exactly where to turn if he intends to leave the main road or see if someone is at the intersection. A beacon light's function is to say "here I am" and even a dim light provides enough contrast against the dark night to serve the purpose. To prevent the dangers caused by a car driving through a pool of light, a beacon light must never shine onto the main road, and not brightly onto the side road. In residential areas, this is usually the only appropriate lighting, and it has the bonus side effect of providing spill lighting onto any sidewalk there for the benefit of pedestrians. On Interstate highways this purpose is commonly served by simply placing reflectors at the sides of the road to reflect the light coming from people's headlights.

Roadway lights

Street lights are not normally intended to illuminate the driving route (headlights are preferred), but to reveal signs and hazards outside of the headlights' beam. Because of the dangers discussed above, roadway lights are properly used sparingly and only when a particular situation justifies increasing the risk. This usually involves an intersection with several turning movements and much signage, situations where drivers must take in much information quickly that is not in the headlights' beam. In these situations (A freeway junction or exit ramp) the intersection may be lit so that drivers can quickly see all hazards, and a well designed plan will have gradually increasing lighting for approximately a quarter of a minute before the intersection and gradually decreasing lighting after it. The main stretches of highways remain unlighted to preserve the driver's night vision and increase the visibility of oncoming headlights. If there is a sharp curve where headlights will not illuminate the road, a light on the outside of the curve is often justified. A SAAB headlight with combination projector/reflector optics A headlight or headlamp is a lamp, usually attached to the front of a vehicle such as a car, with the purpose of illuminating the road ahead during periods of low visibility, such as night or precipitation. ...

If it is desired to light a roadway (perhaps due to heavy and fast multilane traffic), to avoid the dangers of casual placement of street lights it should not be lit intermittently, as this requires repeated eye reajustment which implies eyestrain and temporary blindness when entering and leaving light pools. In this case the system is designed to eliminate the need for headlights. This is usually achieved with bright lights placed on high poles at close regular intervals so that there is consistent light along the route. The lighting goes from curb to curb. ...

Security lighting

A sodium vapor light. This type is often used as security lighting.

Security lighting is similar to high-intensity lighting on a busy major street, with no pools of light and dark, but with the lighted area extending onto people's property, at least to their front door. This requires a different type of fixture and lens. The increased glare experienced by drivers going through the area might be considered a trade-off for increased security. This is what would normally be used along sidewalks in dense areas of cities. Often unappreciated is that the light from a full moon is brighter than most security lighting. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A LPS / SOX streetlight at full power A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... In the field of physical security, security lighting is often used as a preventative and corrective measure against intrusions or other criminal activity on a physical piece of property. ... This article is about the optical device. ... For other uses, see Full Moon. ...

Main manufacturers of street lanterns and/or bulbs

A Bulgarian street lamp, produced by "Svetlina AD" plant in Stara Zagora, Bulgaria.

Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... The popular model 36. ... Stara Zagora (Bulgarian: ) is a city in the cental part of Southern Bulgaria, and represents an important economic center. ...

America

• General Electric, USA.

“GE” redirects here. ...

Europe

• Osram, Germany.
• Philips, the Netherlands
• Schreder, Belgium
• Siemens, Germany.
• Svetlina AD, Bulgaria.

This article or section does not cite its references or sources. ... Philips HQ in Amsterdam Koninklijke Philips Electronics N.V. (Royal Philips Electronics N.V.), usually known as Philips, (Euronext: PHIA, NYSE: PHG) is one of the largest electronics companies in the world, founded and headquartered in the Netherlands. ... Siemens has the following uses: Siemens is a German family name carried by generations of the telecommunications industrialists, including Werner von Siemens, Sir William Siemens, Wilhelm von Siemens and Peter von Siemens Siemens AG is a German electrical and telecommunications company, founded as a telegraph equipment manufacturer by Werner von... The popular model 36. ...

Asia

See also

• History of street lighting in the United States
• Street light interference

The use of street lighting was first recorded in London in 1417 when Sir Henry Barton, the mayor, ordered lanterns with lights to be hanged out on the winter evenings between Hallowtide and Candlemasse. ... Street Light Interference is a phenomenon where a person seems to affect or turn off a street light when passing under it, in an alleged psychic event. ...

References

External links

Wikimedia Commons has media related to:

Streetlamps

• An enthusiast's guide to street lighting - including many close-up photographs of UK street lighting equipment, as well as information on installations through the ages. (UK)
• A UK Streetlighting Forum
• Frangioso's Street Light Gallery - Shows a lot of pictures of streetlights in Boston area.
• Lighting-Gallery.net - Website that allows streetlight or lightbulb collectors join and show pictures of collections, streetlights scenes, and their lightbulb collections or unusual bulbs. This site also allows movies of light-related. This also has a forum to talk about light general related.
• Vicki Sauter's streetlight collection, which includes photos of streetlights from around the world.
• StreetLightNews, News about Streetlight - energy savings, fault monitoring, centralization, maintenance etc.
• Example Installations of Integrated Renewable Power in Street Lighting, An example of a street lighting system with integrated solar and wind generator from Panasonic / Matsushita.