title: Rosey (wrestler)

text: During 2006 and 2007, he also competed for a number of independent promotions, including Great Championship Wrestling, BAW Championship Wrestling, and the Appalachian Wrestling Federation. He also returned to Heartland Wrestling Association for a few matches from 2006 to 2007 with one of the appearances being him challenging Jon Moxley for the HWA Heavyweight Championship on June 10, 2006, at "HWA Road to Destiny".


title: Rosey (wrestler)

text: He wrestled a dark match being billed under his real name for WWE on August 20, 2007, before an episode of "Raw"; he was defeated by Johnny Jeter. He returned the following day for the August 21 "SmackDown!" taping, where he was again defeated by Jeter. Anoaʻi began wrestling in Ohio Valley Wrestling (OVW) in September 2007, WWE's developmental territory, although he was not under contract with WWE. He wrestled several tag team matches with Afa Jr. as the Sons of Samoa, before leaving the promotion.


title: Rosey (wrestler)

text: He returned to wrestling on the independent circuit, competing for companies including EWF. On Saturday, October 31, 2009, Anoaʻi (wrestling as Rosie – Super Hero In Training) made his debut for the Dynamic Wrestling Alliance defeating "Sexy" Sean Casey at the DWA's "Monster Ball" event in Cincinnati, which became the promotion's first televised event. His final match was on July 9, 2016, where he reunited with The Hurricane as the two teamed with Vinny Pacifico in a winning effort against Chris Benne, JGeorge, and Steve Scott.


title: Rosey (wrestler)

text: Before his death, Rosey was running a wrestling promotion called Epic Championship Wrestling in Florida with his father, Sika.


title: Rosey (wrestler)

text: Anoaʻi was a contestant in the ABC reality series, "Fat March" in 2007. The show featured 12 overweight people attempt to walk about in nine states, in order to lose weight and get fit, while competing for a prize pool of US$1.2 million. A press release for the show stated that Anoaʻi was participating because "it wasn't safe for him to compete" as a professional wrestler, and he needed to "lose weight to return to his career". Due to knee injuries, he quit during the fifth episode.


title: Rosey (wrestler)

text: Outside of wrestling, Anoaʻi was involved in several business ventures including a restaurant in Cincinnati called Island Boi BBQ but returned to Florida to be closer to his family and was working with his father in Pensacola.


title: Rosey (wrestler)

text: Anoaʻi was half-Samoan and half-Italian. Anoaʻi's father was Samoan professional wrestler Sika Anoaʻi. He was the brother of Joe Anoaʻi, better known in the WWE as Roman Reigns. His ex-wife, Amanda Vandeberg Schall, current wife of UFC fighter Kerry Schall, is from Mason, Ohio. They had two sons together, Jordan Iles and Koa Rodney Anoa'i, and a daughter Madison Alani Anoa'i.


title: Rosey (wrestler)

text: In January 2014, Anoaʻi was hospitalized due to congestive heart failure (with which he had been diagnosed years earlier) and atrial fibrillation. Anoai’s CHF was related to weight gain as he struggled with a chronic knee injury that also caused hip issues. He died on April 17, 2017, 10 days after his 47th birthday, in Pensacola, Florida, due to complications related to congestive heart failure.


title: Trojan horse (computing)

text: In computing, a Trojan horse is any malware that misleads users of its true intent. The term is derived from the Ancient Greek story of the deceptive Trojan Horse that led to the fall of the city of Troy.


title: Trojan horse (computing)

text: Trojans generally spread by some form of social engineering; for example, where a user is duped into executing an email attachment disguised to appear innocuous (e.g., a routine form to be filled in), or by clicking on some fake advertisement on social media or anywhere else. Although their payload can be anything, many modern forms act as a backdoor, contacting a controller who can then have unauthorized access to the affected computer. Ransomware attacks are often carried out using a Trojan.


title: Trojan horse (computing)

text: Unlike computer viruses and worms, Trojans generally do not attempt to inject themselves into other files or otherwise propagate themselves.


title: Trojan horse (computing)

text: It's not clear where or when the concept, and this term for it, was first used, but by 1971 the first Unix manual assumed its readers knew both:


title: Trojan horse (computing)

text: Another early reference is in a US Air Force report in 1974 on the analysis of vulnerability in the Multics computer systems.


title: Trojan horse (computing)

text: It was made popular by Ken Thompson in his 1983 Turing Award acceptance lecture "Reflections on Trusting Trust", subtitled: "To what extent should one trust a statement that a program is free of Trojan horses? Perhaps it is more important to trust the people who wrote the software." He mentioned that he knew about the possible existence of Trojans from a report on the security of Multics.


title: Trojan horse (computing)

text: Once installed, Trojans may perform a range of malicious actions. Many tend to contact one or more Command and Control (C2) servers across the Internet and await instruction. Since individual Trojans typically use a specific set of ports for this communication, it can be relatively simple to detect them. Moreover, other malware could potentially "take over" the Trojan, using it as a proxy for malicious action.


title: Trojan horse (computing)

text: In German-speaking countries, spyware used or made by the government is sometimes called "govware". Govware is typically a Trojan software used to intercept communications from the target computer. Some countries like Switzerland and Germany have a legal framework governing the use of such software. Examples of govware Trojans include the Swiss MiniPanzer and MegaPanzer and the German "state Trojan" nicknamed R2D2. German govware works by exploiting security gaps unknown to the general public and accessing smartphone data before it becomes encrypted via other applications.


title: Trojan horse (computing)

text: Due to the popularity of botnets among hackers and the availability of advertising services that permit authors to violate their users' privacy, Trojans are becoming more common. According to a survey conducted by BitDefender from January to June 2009, "Trojan-type malware is on the rise, accounting for 83% of the global malware detected in the world." Trojans have a relationship with worms, as they spread with the help given by worms and travel across the internet with them. BitDefender has stated that approximately 15% of computers are members of a botnet, usually recruited by a Trojan infection.


title: Trojan horse (computing)

text: A "Trojan horse" is a program that purports to perform some obvious function, yet upon execution it compromises the user's security. One easy program is a new version of the Linux sudo command. The command is then copied to a publicly writable directory like codice_1. If an administrator happens to be in that directory and executes codice_2, then the "Trojan horse" might be executed. Here is a working version:


title: Trojan horse (computing)

text: To prevent a command-line based "Trojan horse", set the codice_3 entry in the codice_4 environment variable to be located at the tail end. For example: codice_5.


title: Trojan horse (computing)

text: The computer term "Trojan horse" is derived from the legendary Trojan Horse of the ancient city of Troy. For this reason "Trojan" is often capitalized. However, while style guides and dictionaries differ, many suggest a lower case "trojan" for normal use.


title: Gender binary

text: The gender binary (also known as gender binarism) is the classification of gender into two distinct, opposite forms of masculine and feminine, whether by social system, cultural belief, or both simultaneously. Most cultures use a gender binary, having two genders (boys/men and girls/women).


title: Gender binary

text: In this binary model, "gender" and "sexuality" may be assumed by default to align with one's genetic or gamete-based sex, i.e. one's sex assigned at birth. This may include certain expectations of how one dresses themselves, their behavior, sexual orientation, names or pronouns, which restroom they use, and other qualities. For example, when a male is born, gender binarism may assume that the male will be masculine in appearance, have masculine character traits and behaviors, as well as having a heterosexual attraction to females. These expectations may reinforce negative attitudes, biases, and discrimination towards people who display expressions of gender variance or nonconformity or those whose gender identity is incongruent with their birth sex.


title: Gender binary

text: The term "gender binary" describes the system in which a society allocates its members into one of two sets of gender roles, gender identities, and attributes based on the type of genitalia they have. In the case of intersex people, those with rare genetic abnormalities which give them the sex organs of both sexes may have difficulties fitting into this system.


title: Gender binary

text: Scholars who study the gender binary from an intersectional feminist and critical race theory perspective argue that during the process of European colonization of the U.S., a binary system of gender was enforced as a means of protecting patriarchal norms and upholding European nationalism.


title: Gender binary

text: Traditional gender roles are influenced by the media, religion, mainstream education, political systems, cultural systems, and social systems. Major religions such as Islam and Christianity, in particular, act as authorities for gender roles. Islam, for example, teaches that mothers are the primary care givers to their children. The Catholic Church, the largest Christian denomination, only ordains cisgender men as priests. Christianity supports its adherence to a gender binary with the Book of Genesis in the Bible, where it is declared in verse 27 that "God created man in His own image; in the image of God He created him; male and female He created them." Orthodox Judaism also forbids women to be ordained as rabbis and serve as clergy in their congregations.


title: Gender binary

text: In English, some nouns (e.g., boy), honorific titles (e.g., Miss), occupational titles (e.g., actress), and personal pronouns (e.g., she, his) are gendered, and they fall into a male/female binary. According to Hyde and colleagues, children raised within English-speaking (and other gendered-language) environments come to view gender as a binary category. They state that for children who learn English as their primary language in the U.S., adults' use of the gender binary to explicitly sort individuals (i.e. "boys" and "girls" bathrooms and sports teams), and not just the presence of gender markers, causes gender biases.


title: Gender binary

text: Along with using the gender binary to categorize human bodies, cultures that obey the binary may also use it to label things, places, and ideas. For example, in American culture people identify playing sports as a masculine activity and shopping as a feminine activity, blue is a color for boys while pink is for girls, care work is a feminine profession while management is associated with masculinity, etc. Some languages, like Spanish, even gender their words into masculine and feminine forms.


title: Gender binary

text: Gender binarism may create institutionalized structures of power, and individuals who identify outside traditional gender binaries may experience discrimination and harassment. Many LGBT people, notably youth activist groups, advocate against gender binarism. Many individuals within the LGBT+ community report an internal hierarchy of power status. Some who do not identify within a binary system experience being at the bottom of the hierarchy. The multitude of different variables such as race, ethnicity, age, gender, and more can lower or raise one's perceived power.


title: Gender binary

text: Worldwide, there are many individuals and several subcultures that can be considered exceptions to the gender binary or specific transgender identities. In addition to individuals whose bodies are naturally intersex, there are also specific ceremonial and social roles that are seen as third gender. The hijra of South Asia and some Two-Spirit Indigenous Peoples of North America are often cited as examples. Feminist philosopher María Lugones argues that Western colonizers imposed their dualistic ideas of gender on indigenous peoples, replacing pre-existing indigenous concepts.


title: Gender binary

text: In the contemporary West, non-binary or genderqueer people do not adhere to the gender binary by refusing terms like "male" and "female", as they do not identify as either. Transgender people have a unique place in relation to the gender binary. In some cases, attempting to conform to societal expectations for their gender, transgender individuals may opt for surgery, hormones, or both.


title: Gender binary

text: Ball culture is an example of how the LGBT community interprets and rejects the gender binary. "Paris is Burning", a film directed by Jennie Livingston, depicts New York's ballroom scene in the late 1980's. To compete in the Balls, men, women, and everyone in between create costumes and walk in their respective categories: Butch Queen, Transmale Realness, and Femme Queen to name a few. During the Balls, the gender binary is thrown out the window, and the people competing are allowed to express themselves however they interpret the category. Within the scenes of people competing in various categories there's a narrative that describes life outside the gender binary in New York. Since the film came out, there's been a decline in the Ballroom scene due to the rise of media and the appropriation of the Drag culture.


title: Gender binary

text: Some scholars have contested the existence of a clear gender binary. Judith Lorber explains the problem of failing to question dividing people into these two groups "even though they often find more significant within-group differences than between-group differences." Lorber argues that this corroborates the fact that the gender binary is arbitrary and leads to false expectations of both men and women. Instead, there is growing support for the possibility of utilizing additional categories that compare people without "prior assumptions about who is like whom".


title: Gender binary

text: This idea of a gender as a binary is thought to be an oppressive means of reflecting differential power dynamics.


title: Gender binary

text: In her paper "The Five Sexes: Why Male and Female Are Not Enough", Anne Fausto-Sterling discusses the existence of intersex people, individuals possessing a combination of male and female sexual characteristics, who are seen as deviations from the norm, and who frequently undergo coercive surgery at a very young age in order to maintain the two-gender system. According to Fausto-Sterling the existence of these individuals challenges the standards of gender binaries and puts into question society's role in constructing gender. Fausto-Sterling says that modern practitioners encourage the idea that gender is a cultural construct and concludes that, "we are moving from an era of sexual dimorphism to one of variety beyond the number 2."


title: Gender binary

text: Cisnormativity is a product of the gender binary that assumes people are cisgender, meaning that their gender identity matches their sex assigned at birth. Both binary and nonbinary transgender individuals are excluded from this ideology. This leads to individuals outside the gender binary experiencing disparities in health and violence at individual, interpersonal, and institutional levels due to their non-normative status.


title: Gender binary

text: Gender binarism poses limitations on the adequacy of medical care provided to gender nonconforming patients. There is a large gap in medical literature on non-binary populations who have unique healthcare needs. A lack of cultural competency about nonbinary gender identities among providers contribute to nonbinary transgender individuals facing greater health disparities than both binary transgender and cisgender individuals. However, cisnormativity affects transgender individuals that identify within the gender binary as well. An individual's discomfort due to incongruence with their gender identity and sex assigned at birth used to be classified as a mental illness. "Gender identity disorder" entered the DSM-IV in 1980 and was used by doctors to pathologize transgender individuals. While it was updated to the term "gender dysphoria" when the DSM-V was published in 2013, transgender health is otherwise largely absent from medical curriculums. Health systems remain cisnormative and discriminative, which lead to adverse health outcomes for transgender populations.


title: Gender binary

text: Transgender individuals are at a greater risk of physical and sexual intimate partner violence than cisgender individuals. The rates of intimate partner violence among transgender populations are referred to as “epidemic levels” and they are classified as a high risk population. Discrimination against transgender individuals is believed by researchers to contribute to greater risk of intimate partner violence. This is especially prominent in areas where gender identity is not legally protected against discrimination.


title: Gender binary

text: Transgender women of color cite both their race or ethnicity and their gender identity as factors that result in discrimination against them while white transgender women cited only their gender identity; transgender women of color experience both racism and transphobia.


title: Gender binary

text: Self-expression that opposes the gender binary is stigmatized and in some cases has been criminalized. The United States has a history of laws and policies against cross-dressing, such as New York's "walking while trans" law and the informal three-article rule used during the 1940s-1960s by police to punish people that dressed in a way that defied the gender binary.


title: Gender binary

text: There are public figures that have opposed the gender binary by wearing clothing not typically associated with their perceived gender or their gender identity, such as Prince, David Bowie, Kurt Cobain, Jaden Smith, Ruby Rose, Rain Dove, Billy Porter, and Harry Styles. Public figures that identify as of non-binary gender include Sam Smith, Indya Moore, Brigette Lundy-Paine, King Princess, Johnathan Van Ness, Bex Taylor-Klaus, Amandla Stenberg, Demi Lovato, and more.


title: Gender binary

text: Harry Styles' appearance on the cover of American "Vogue" in 2020 was the first instance with a cisgender man doing so by himself. This was groundbreaking as well as controversial due to the fact that on the cover he wore both a dress, a clothing item associated with women, as well as a blazer, which is associated with men. His embrace of clothing associated with women and men is a rejection of the gender binary.


title: Gender binary

text: Personal pronouns in the English language are typically associated with either men (he/him) or women (she/her), which excludes people who do not identify as a man or a woman. However, gender-neutral pronouns, such as singular "they" pronouns (they/them) are sometimes used by nonbinary and gender nonconforming individuals. A 2019 study found that "close to 1 in 5 Americans personally know someone who uses gender-neutral pronouns such as ‘they’ instead of ‘he’ or “’she’”. In addition, people may use neopronouns in place of other personal pronouns. Examples of neopronouns include xe/xem, ze/zim, and sie/hir.


title: Traffic light

text: Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control flows of traffic.


title: Traffic light

text: Traffic lights consist normally of three signals, transmitting meaningful information to drivers and riders through colours and symbols including arrows and bicycles. The regular traffic light colours are red, yellow, and green arranged vertically or horizontally in that order. Although this is internationally standardised, variations exist on national and local scales as to traffic light sequences and laws.


title: Traffic light

text: The method was first introduced in December 1868 on Parliament Square in London to reduce the need for police officers to control traffic. Since then, electricity and computerised control has advanced traffic light technology and increased intersection capacity. The system is also used for other purposes, for example, to control pedestrian movements, variable lane control (such as tidal flow systems or smart motorways), and railway level crossings.


title: Traffic light

text: The first system of traffic signals was installed as a way to replace police officer control of vehicular traffic outside the Houses of Parliament in London on 9 December 1868. In the first two decades of the 20th century, semaphore traffic signals like the one in London were in use all over the United States with each state having its own design of the device. In many cases, it was controlled by a traffic officer who would blow a whistle before changing the commands on this signal to help alert travellers of the change.


title: Traffic light

text: In 1912, the first electric traffic light was developed by Lester Wire, a policeman in Salt Lake City, Utah. It was installed by the American Traffic Signal Company on the corner of East 105th Street and Euclid Avenue in Cleveland, Ohio. The first four-way, three-colour traffic light was created by police officer William Potts in Detroit, Michigan in 1920. He was concerned about how police officers at four different light signals could not change their lights all at the same time. The answer was a third light that was coloured yellow, which was the same colour used on the railroad. In 1922 traffic towers were beginning to be controlled by automatic timers. The main advantage of the use of the timer was that it saved cities money by replacing traffic officers. The city of New York was able to reassign all but 500 of its 6,000 officers working on the traffic squad; this saved the city $12,500,000.


title: Traffic light

text: The control of traffic lights made a big turn with the rise of computers in America in the 1950s. One of the best historical examples of computerized control of lights was in Denver in 1952. In 1967, the city of Toronto was the first to use more advanced computers that were better at vehicle detection. The computers maintained control over 159 signals in the cities through telephone lines.


title: Traffic light

text: A set of lights, known as a signal head, may have one, two, three, or more aspects. The most common signal type has three aspects facing the oncoming traffic: red on top, amber below, and green below that. Additional aspects may be fitted to the signal, usually to indicate specific restrictions or filter movements.


title: Traffic light

text: The 1968 Vienna Convention on Road Signs and Signals Chapter III provides international standards for the setup of traffic signal operations. Not all states have ratified the convention.


title: Traffic light

text: A three-colour signal head should have three non-flashing lights which are red, yellow, and green, either arranged horizontally (on the side opposite to the direction of traffic) or vertically (with red on top). A two-colour signal head may be used in temporary operation and consists of red and green non-flashing lights. In both cases, all lights should be circular or arrow-shaped.


title: Traffic light

text: Permissible signals for regulating vehicle traffic (other than public transport vehicles) are outlined in Article 23:


title: Traffic light

text: Green arrows are added to signals to indicate that drivers can travel in a particular direction, while the main lights for that approach are red, or that drivers can only travel in one particular direction. Alternatively, when combined with another green signal, they may indicate that turning traffic has priority over oncoming traffic (known as a "filter arrow").


title: Traffic light

text: The United States is not party to the Convention and the Manual on Uniform Traffic Control Devices (MUTCD) outlines correct operation in that country. The MUTCD specifies the following vehicular signals:


title: Traffic light

text: In the US, a single signal head shall have three, four, or five aspects (though a single aspect green arrow may be displayed to indicate a continuous movement). The signals must be arranged red, yellow, and green vertically (top to bottom) or horizontally (left to right).


title: Traffic light

text: In the US, a single-aspect flashing yellow signal can be used to raise attention to a warning sign and a single-aspect flashing red signal can be used to raise attention to a STOP, DO NOT ENTER, or WRONG WAY sign. Flashing red or amber lights, known as "intersection control beacons", are used to reinforce stop signs at intersections.


title: Traffic light

text: Generally, at least one direction of traffic at an intersection has a green light (green aspect) at any moment in the cycle. In some jurisdictions, for a brief time, all signals at an intersection show red at the same time, to clear any traffic in the intersection. The delay can depend on traffic, road conditions, the physical layout of the intersection, and legal requirements. Thus modern signals are built to allow the "all red" in an intersection, even if the feature is not used.


title: Traffic light

text: Some signals have no "all red" phase: the light turns green for cross traffic the instant the other light turns red.


title: Traffic light

text: Another variant in some locations is the pedestrian scramble, where all the traffic lights for vehicles become red, and pedestrians are allowed to walk freely, even diagonally, across the intersection. Use of the Pedestrian signals (see below) will alter the traffic signal cycle.


title: Traffic light

text: In the Canadian province of Quebec and the Maritime provinces, lights are often arranged horizontally, but each aspect is a different shape: red is a square (larger than the normal circle) and usually in pairs at either end of the fixture, yellow is a diamond, and green is a circle. In many southern and southwestern U.S. states, most traffic signals are similarly horizontal in order to ease wind resistance during storms and hurricanes.


title: Traffic light

text: Japanese traffic signals mostly follow the same rule except that the "go" signals are referred to as 青 (blue), which they historically were in fact, but this caused complications with the international "green for go" rule, so in 1973 a decree was issued that the "go" light should be changed to the bluest possible hue of green, thus making it factually greener without having to change the name from 青(blue) to 緑(green).


title: Traffic light

text: A speed sign is a special traffic light, variable traffic sign, or variable-message sign giving drivers a recommended speed to approach the next traffic light in its green phase and avoid a stop due to reaching the intersection when lights are red.


title: Traffic light

text: The three-aspect standard is also used at locks on the Upper Mississippi River. Red means that another vessel is passing through. Amber means that the lock chamber is being emptied or filled to match the level of the approaching vessel. After the gate opens, green means that the vessel may enter.


title: Traffic light

text: Railroad signals, for stopping trains in their own right of way, generally use the opposite positioning of the colours; that is, for signals above the driver's eyeline, green on top and red below is the standard placement of the signal colours on railroad tracks. There are three reasons for this variation: there is no risk that railway signals will be masked by a tall vehicle between the driver and the signal; train speeds in fog are much higher than for road vehicles, so it is important that the most restrictive signal is closest to the driver's eyeline; and with railway signals often in exposed rural locations, there is a risk of any signal other than the bottom one being masked by snow building up on the hood of the signal below.


title: Traffic light

text: Pedestrian signals are used to inform pedestrians when to cross a road. Most pedestrian signal heads will have two lights: a 'walk' light (normally a walking human figure, typically coloured green or white) and a 'don't walk' light (normally either a red man figure or a hand), though other variations exist.


title: Traffic light

text: Where pedestrians need to cross the road between junctions, a signal-controlled crossing may be provided as an alternative to a zebra crossing or uncontrolled crossing. Traffic lights are normally used at crossings where vehicle speeds are high, where either vehicle or pedestrian flows are high or near signalised junctions.


title: Traffic light

text: In the UK, this type of crossing is called a pelican crossing, though more modern iterations are puffin and pedex crossings. In the UK, these crossings normally need at least four traffic signals, which are of a regular type (red, amber, and green), two facing in each direction. Furthermore, pedestrians will be provided with push buttons and pedestrian signals, consisting of a red and green man. Farside signals are located across the crossing, while nearside signals are located below the traffic lights, facing in the direction of oncoming traffic.


title: Traffic light

text: A HAWK beacon is a special type of traffic used in the US at mid-block crossings. These consist of two red signals above a single yellow signal. The beacon is unlit until a pedestrian pushes the cross button. Then a yellow light will show, followed by both red lights, at which point the 'Walk' symbol will illuminate for pedestrians. At the end of the crossing phase, the 'Don't Walk' symbol will flash, as will the yellow traffic light.


title: Traffic light

text: Pedestrians are usually incorporated into urban signalised junctions in one of four ways: no facilities, parallel walk, walk with traffic, or all-red phases.


title: Traffic light

text: No facilities may be provided if pedestrian demand is low, in areas where pedestrians are not permitted, or if there is a subway or overpass. No provision of formal facilities means pedestrians will have to self-evaluate when it is safe to cross, which can be intimidating for pedestrians.


title: Traffic light

text: With a 'parallel walk' design, pedestrians walk alongside the traffic flow. A leading pedestrian interval may be provided, whereby pedestrians get a 'walk' signal before the traffic gets a green light, allowing pedestrians to establish themselves on the crossing before vehicles begin to turn, to encourage drivers to give way.


title: Traffic light

text: A 'walk with traffic' facility allows pedestrians to go at the same time as other traffic movements with no conflict between movements. This can work well on one-way roads, where turning movements are banned or where the straight-ahead movement runs in a different stage from the turning movement. A splitter island could also be provided. Traffic will pass on either side of the island and pedestrians can cross the road safely between the other flows.


title: Traffic light

text: An all-red stage, also known as a full pedestrian stage or a pedestrian scramble, holds all vehicular traffic at the junction to allow pedestrians time to safely cross. This may require a longer cycle time and increase pedestrian wait periods. This can be eased by providing two pedestrian stages. This also allows diagonal crossings to be provided, known as a pedestrian scramble or the Barnes Dance, such as the famous Shibuya crossing in Tokyo. The Barnes Dance is named after an American traffic engineer, Henry A. Barnes. Barnes did not claim to have invented the system but was a strong advocate of it, having observed the difficulties his daughter faced crossing the road to get to school.


title: Traffic light

text: Pedestrian countdown timers are becoming common at urban signal-controlled crossings. Where a pedestrian countdown is shown, it is normally used in conjunction with the flashing hand signal (in the US and Canada) or blackout period (UK), showing the amount of time remaining in seconds until the end of the flashing hand or blackout.


title: Traffic light

text: Pedestrian countdown timers do not significantly increase or reduce the number of red- and amber-light runners (drivers). Studies have found that pedestrian countdown timers do significantly improve pedestrian compliance over traditional pedestrian signals; however, results are mixed.


title: Traffic light

text: In some jurisdictions such as Australia, pedestrian lights are associated with a sound device, for the benefit of blind and visually impaired pedestrians. These make a slow beeping sound when the pedestrian lights are red and a continuous buzzing or fast beeping sound when the lights are green. In the Australian States of Queensland, New South Wales, Victoria, and Western Australia, the sound is produced in the same unit as the push buttons. In a circle above the button, the sound is produced and can be felt along with a raised arrow that points in the direction to walk. This system of assistive technology is also widely used at busy intersections in Canadian cities.


title: Traffic light

text: In the United Kingdom, the Puffin crossings and their predecessor, the Pelican crossing, will make a fast beeping sound to indicate that it is safe to cross the road. The beeping sound is disabled during the nighttime so as not to disturb any nearby residents.


title: Traffic light

text: In some states in the United States, at some busy intersections, buttons will make a beeping sound for blind people. When the light changes, a speaker built into the button will play a recording to notify blind people that it is safe to cross. When the signal flashes red, the recording will start to count down with the countdown timer.


title: Traffic light

text: In several countries such as New Zealand, technology also allows deaf and blind people to feel when lights have changed to allow safe crossing. A small pad, housed within an indentation in the base of the box housing the button mechanism, moves downwards when the lights change to allow crossing. This is designed to be felt by anyone waiting to cross who has limited ability to detect sight or sound.


title: Traffic light

text: In Japan, a traffic light emits an electronic sound that mimics the sound of birdsong to help the visually impaired. Some traffic lights fix the order and type of sound so that they can tell which direction is a green light. In general, "Piyo" (peep) and "Piyo-piyo", which is a small bird call, and "Kakkō" and "Ka-kakkō", which is a cuckoo call, are associated with this system.


title: Traffic light

text: Some pedestrian crossings in Lithuania make a slowish beeping sound indicating that the traffic light is about to turn off.


title: Traffic light

text: Where cycle lanes or cycle tracks exist on the approach to a signal-controlled junction, it must be considered how to incorporate cyclists safely into the junction to reduce conflict between motor vehicles and cyclists.


title: Traffic light

text: An advanced stop line can be placed after the stop line at traffic lights. This allows cyclists to position themselves in front of traffic at a red light and get a headstart.


title: Traffic light

text: In the US, design advice typically advises that the cycle lane should continue through the junction to the left of the right-turn lane; however, this creates conflict where motor vehicles wish to enter the right lane, as they must cross the cycle lane at a bad angle.


title: Traffic light

text: Under Dutch engineering principles, cyclists are instead kept to the right of the junction, with protected kerbs. This improves safety by putting cyclists into the eyeline of motor vehicles at the stop line, allowing cyclists a headstart over turning traffic. This design also allows cyclists to complete far-side turns without having to wait in the centre of the junction.


title: Traffic light

text: UK engineers have further innovated the design by introducing the Cycle Optimised Protected Signals (CYCLOPS junction) in Manchester and other cities. This places the cycle track around the edge of the signal junction and gives cyclists and pedestrians a single all-red phase, entirely separate from motor traffic and shortens pedestrian crossing times.


title: Traffic light

text: Alternatively, cyclists can be considered pedestrians on approach to a junction, or where a cycle track crosses a road and combined pedestrian-cyclist traffic lights (known as Toucan crossings in the UK) can be provided.


title: Traffic light

text: Traffic lights for public transport often use signals that are distinct from those for private traffic. They can be letters, arrows or bars of white or coloured light.


title: Traffic light

text: Some systems use the letter B for buses and T for trams. The METRO light rail system in Minneapolis, Minnesota, the Valley Metro Rail in Phoenix, Arizona, and the RTA Streetcar System in New Orleans use a simplified variant of the Belgian/French system in the respective city's central business district where only the "go" and "stop" configurations are used. A third signal equal to amber is accomplished by flashing the "go" signal.


title: Traffic light

text: In some European countries and Russia, dedicated traffic signals for public transport (tram, as well any that is using a dedicated lane) four white lights that form the letter T. If the three top lamps are lit, this means "stop". If the bottom lamp and some lamps on the top row are lit, this means permission to go in a direction shown. In the case of a tram signal, if there are no tram junctions or turns at an intersection, a simpler system of one amber signal in the form of the letter T is used instead; the tram must proceed only when the signal is lit.


title: Traffic light

text: In North European countries, the tram signals feature white lights of different forms: "S" for "stop", "—" for "caution" and arrows to permit passage in a given direction.


title: Traffic light

text: The Netherlands uses a distinctive "negenoog" (nine-eyed) design shown on the top row of the diagram; bottom row signals are used in Belgium, Luxembourg, France, and Germany. The signals mean (from left to right): "go straight ahead", "go left", "go right", "go in any direction" (like the "green" of a normal traffic light), "stop, unless the emergency brake is needed" (equal to "yellow"), and "stop" (equal to "red").


title: Traffic light

text: In Japan, tram signals are under the regular vehicle signal; however, the colour of the signal intended for trams is orange. In Sweden, All signals use white lighting and special symbols ("S", "–" and an arrow) to distinguish them from regular signals. The small light at the top tells the driver when the vehicle's transponder signal is received by the traffic light. In Hong Kong, an amber T-signal is used for trams, in place of the green signal. In addition, at any tramway junction, another set of signals is available to indicate the direction of the tracks. In Australia and New Zealand, a white "B" or "T" sometimes replaces the green light indicating that buses or trams (respectively) have right of way.


title: Traffic light

text: Some regions have signals that are interruptible, giving priority to special traffic, usually emergency vehicles such as fire apparatus, ambulances, and police squad cars. Most of the systems operate with small transmitters that send radio waves, infrared signals, or strobe light signals that are received by a sensor on or near the traffic lights. Some systems use audio detection, where a certain type of siren must be used and detected by a receiver on the traffic light structure.


title: Traffic light

text: Upon activation, the normal traffic light cycle is suspended and replaced by the "preemption sequence": the traffic lights to all approaches to the intersection are switched to "red" with the exception of the light for the vehicle that has triggered the preemption sequence. Sometimes, an additional signal light is placed nearby to indicate to the preempting vehicle that the preempting sequence has been activated and to warn other motorists of the approach of an emergency vehicle. The normal traffic light cycle resumes after the sensor has been passed by the vehicle that triggered the preemption.


title: Traffic light

text: In lieu of preemptive mechanisms, in most jurisdictions, emergency vehicles are not required to respect traffic lights. However, emergency vehicles must slow down, proceed cautiously and activate their emergency lights to alert oncoming drivers to the preemption when crossing an intersection against the light.


title: Traffic light

text: Unlike preemption, which immediately interrupts a signal's normal operation to serve the preempting vehicle and is usually reserved for emergency use, "priority" is a set of strategies intended to reduce delay for specific vehicles, especially mass transit vehicles such as buses. A variety of strategies exist to give priority to transit but they all generally work by detecting approaching transit vehicles and making small adjustments to the signal timing. These adjustments are designed to either decrease the likelihood that the transit vehicle will arrive during a red interval or decrease the length of the red interval for those vehicles that are stopped. Priority does not guarantee that transit vehicles always get a green light the instant they arrive as preemption does.


title: Traffic light

text: Some jurisdictions, particularly in North America, permit drivers to make a kerb-to-kerb turn (i.e. not crossing other traffic streams) at a red light, provided they first come to a complete stop and give way to other traffic and pedestrians. The rule has been criticised for endangering pedestrians, and some highway authorities have banned turning on red at specific junctions.


title: Traffic light

text: A green arrow may display to require drivers to turn in a particular direction only or to allow drivers to continue in a particular direction when the signal is red. Generally, a green phase is illuminated at the beginning of the green phase (a "leading turn") or at the end of the green phase (a "lagging turn").


title: Traffic light

text: An 'indicative arrow' may be displayed alongside a green light. This indicates to drivers that oncoming traffic is stopped, such that they do not need to give way to that traffic when turning across it. As right-turning traffic (left-side drive) or left-turning traffic (right-side drive) does not normally have priority, this arrow is used to allow turning traffic to clear before the next phase begins.


title: Traffic light

text: Flashing yellow arrows typically indicate that road users must give way (to other drivers and pedestrians) before making a movement in the direction of the arrow. These are used because they are safer, cause less delay, and are more flexible. Flashing yellow arrows will normally be located below the solid yellow.


title: Traffic light

text: Without an all-red phase, cross-turning traffic may be caught in a yellow trap. When the signal turns yellow, a turning driver may assume oncoming traffic will stop and a crash may result. For this reason, the US bans sequences that may cause a yellow trap. This can also happen when emergency vehicles or railroads preempt normal signal operation.


title: Traffic light

text: A hook turn, or two-stage turn, is generally used to allow lighter vehicles such as cycles or motorcycles to turn across oncoming traffic. Such vehicles when permitted can move to the nearside of the junction and position themselves in front of side road traffic, waiting for the side road traffic to gain a green signal before completing the turn. In Australia, such turns were the standard right turn until the 1950s. Hook turns remaining in Australia are generally in the Melbourne central city area to ensure cars do not wait on centre-lane tram tracks and delay trams.


title: Traffic light

text: Variable lane control is a form of intelligent transportation systems which involve the use of lane-use control signals, typically on a gantry above a carriageway. These lights are used in tidal flow systems to allow or forbid traffic to use one or more of the available lanes by the use of green lights or arrows (to permit) or by red lights or crosses (to prohibit). Variable lane control may be in use at toll plazas to indicate open or closed booths; during heavy traffic to facilitate merging traffic from a slip road.


title: Traffic light

text: In the US, most notably the Southeastern, there often is a "continuous-flow" lane. This lane is protected by a single, constant-green arrow pointing down at the lane(s) permitting the continuous flow of traffic, without regard to the condition of signals for other lanes or cross streets. Continuous lanes are restricted in that vehicles turning from a side street may not cross over the double white line to enter the continuous lane, and no lane changes are permitted to the continuous lane from an adjacent lane or from the continuous lane to an adjacent lane until the double white line has been passed. Some continuous lanes are protected by a raised curb located between the continuous lane and a normal traffic lane, with white and/or amber reflective paint or tape, prohibiting turning or adjacent traffic from entering the lane. Continuous-flow traffic lanes are found only at "T" intersections where there is no side street or driveway entrance on the right side of the main thoroughfare; additionally, no pedestrians are permitted to cross the main thoroughfare at intersections with a continuous-flow lane, although crossing at the side street may be permitted. Intersections with continuous-flow lanes will be posted with a white regulatory sign approximately before the intersection with the phrase, "right lane continuous traffic," or other, similar, wording. If the arrow is extinguished for any reason, whether by malfunction or design, traffic through the continuous lane will revert to the normal traffic pattern for adjacent lanes, except that turning or moving into or out of the restricted lane is still prohibited.


title: Traffic light

text: Traffic light failure in most jurisdictions in Australia and countries in Europe must be handled by drivers as a priority-to-the-right intersection, or an all-way stop elsewhere, pending the arrival of a police officer to direct traffic. In Armenia, Belarus, Belgium, Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, France, Georgia, Germany, Greece, Iceland, Italy, Kazakhstan, Kosovo, Latvia, Lithuania, Luxembourg, Moldova, Netherlands, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Sweden, Switzerland (and Liechtenstein), Turkey, and Ukraine, traffic lights may have additional right-of-way signs mounted above, below or next to the traffic lights; these take effect when the lights are no longer active or are flashing amber. A flashing amber traffic light usually indicates you have a yield or stop sign as a redundant sign, while a turned-off traffic light usually indicates you have the right-of-way. In the UK and parts of North America, drivers simply treat the junction as being uncontrolled when traffic lights fail, giving way as appropriate, unless a police officer is present. In much of the United States failed traffic signals must be treated as all-way stop intersections.


title: Traffic light

text: In the US, traffic lights inactive at night time emit an amber-coloured flashing signal in directions owing priority while the intersecting street emits a flashing red light, requiring drivers to stop before proceeding.


title: Traffic light

text: Traditionally, incandescent and halogen bulbs were used. Because of the low efficiency of light output and a single point of failure (filament burnout), some traffic authorities are choosing to retrofit traffic signals with LED arrays that consume less power, have increased light output, and last significantly longer. Moreover, in the event of an individual LED failure, the aspect will still operate albeit with a reduced light output. The light pattern of an LED array can be comparable to the pattern of an incandescent or halogen bulb fitted with a prismatic lens.


title: Traffic light

text: The low energy consumption of LED lights can pose a driving risk in some areas during winter. Unlike incandescent and halogen bulbs, which generally get hot enough to melt away any snow that may settle on individual lights, LED displays – using only a fraction of the energy – remain too cool for this to happen. As a response to the safety concerns, a heating element on the lens was developed.


title: Traffic light

text: Signals such as the 3M High Visibility Signal utilize light-diffusing optics and a Fresnel lens to create the signal indication. The light from a 150 W PAR46 sealed-beam lamp in these "programmable visibility" signals passes through a set of two glass lenses at the back of the signal. The first lens, a frosted glass diffusing lens, diffuses the light into a uniform ball of light around five inches in diameter. The light then passes through a nearly identical lens known as an optical limiter (3M's definition of the lens itself), also known as a "programming lens", also five inches in diameter.


title: Traffic light

text: Using a special aluminium foil-based adhesive tape, these signals are "masked" or programmed by the programming lens so that only certain lanes of traffic will view the indication. At the front of these programmable visibility signals is a 12" Fresnel lens, each lens tinted to meet United States Institute of Transportation Engineers (ITE) chromaticity and luminance standards. The Fresnel lens collimates the light output created by the lamp and creates a uniform display of light for the lane in which it is intended. These signals were first developed by the 3M Company in the late 1960s and were popular in the late 1970s as traffic density increased.


title: Traffic light

text: In addition to being positioned and mounted for desired visibility for their respective traffic, some traffic lights are also aimed, louvered, or shaded to minimize misinterpretation from other lanes. For example, a Fresnel lens on an adjacent through-lane signal may be aimed to prevent left-turning traffic from anticipating its own green arrow.


title: Traffic light

text: Today, McCain Traffic Systems is the only U.S.-based manufacturer producing optically programmable traffic signals similar to the 3M model. Intelight Inc. manufactures a programmable traffic signal that uses a software-controlled LED array and electronics to steer the light beam toward the desired approach. The signal is programmed unlike the 3M and McCain models. It requires a connection to a laptop or smartphone with the manufacturer’s software installed. Connections can be made directly with a direct-serial interface kit, or wirelessly with a radio kit over WIFI to the signal.


title: Traffic light

text: In addition to aiming, Fresnel lenses, and louvers, visors and back panels are also useful in areas where sunlight would diminish the contrast and visibility of a signal face.


title: Traffic light

text: Typical applications for these signals were skewed intersections, specific multi-lane control, left-turn pocket signals, or other areas where complex traffic situations existed.


title: Traffic light

text: Conventional traffic signal lighting, still common in some areas, uses a standard light bulb. Typically, a 67, 69, or 115-watt medium-base (household lamp in the US) light bulb provides the illumination. The light then bounces off a mirrored glass or polished aluminium reflector bowl, and out through a polycarbonate plastic or glass signal lens. In some signals, these lenses were cut to include a specific refracting pattern. Crouse-Hinds is one notable company for this practice. In the 1930s throughout the 1950s, they used a beaded prismatic lens with a "smiley" pattern embossed into the bottom of each lens.


title: Traffic light

text: In the United States, traffic lights are currently designed with lights approximately in diameter. Previously the standard had been ; however, those are slowly being phased out in favour of the larger and more visible 12 inch lights. Variations used have also included a hybrid design, which had one or more 12 inch lights along with one or more lights of on the same light. For example, these "12-8-8" (along with 8-8-8) lights are standard in most jurisdictions in Ontario, Manitoba, and British Columbia (that, is, the red light is 12 and others 8, making the red more prominent).


title: Traffic light

text: In the United Kingdom, 12-inch lights were implemented only with Mellor Design Signal heads designed by David Mellor. These were designed for symbolic optics to compensate for the light loss caused by the symbol. However, following a study sponsored by the UK Highways Agency and completed by Aston University, Birmingham, UK, an enhanced optical design was introduced in the mid-1990s. Criticism of sunlight "washout" (cannot see the illuminated signal due to sunlight falling on it), and "sun-phantom" (signal appearing to be illuminated even when not due to sunlight reflecting from the parabolic mirror at low sun angles), led to the design of a signal that used lenslets to focus light from a traditional incandescent bulb through apertures in a matt black front mask. This cured both problems in an easily manufactured solution. This design proved very successful and was taken into production by a number of traffic signal manufacturers through the engineering designs of Dr. Mark Aston, working firstly at the SIRA Ltd in Kent, and latterly as an independent optical designer. The manufacturers took a licence for the generic design from the Highways Agency, with Dr. Aston engineering a unique solution for each manufacturer. Producing both bulb and LED versions of the signal aspects, these signals are still the most common type of traffic light on UK roads. With the invention of anti-phantom, highly visible Aston lenses, lights of could be designed to give the same output as plain lenses, so a larger surface area was unnecessary. Consequently, lights of are no longer approved for use in the UK and all lights installed on new installations have to be in accordance with TSRGD (Traffic Signs Regulations and General Directions). Exemptions are made for temporary or replacement signals.


title: Traffic light

text: With technologies in developed countries continuing to advance, there is now an increasing move to develop and implement smart traffic lights on the roads. These are systems that adapt to information that is received from a central computer about the position, speed, and direction of vehicles. They try to communicate with cars to alert drivers of impending light changes and reduce motorists' waiting time considerably. Trials are currently being conducted for the implementation of these advanced traffic lights but there are still many hurdles to widespread use that need to be addressed; one of which is the fact that few cars yet have the required systems to communicate with these lights.


title: Traffic light

text: In some instances, small vehicles such as motorcycles, scooters, and bicycles may not be detected, leaving the traffic light controller unaware of their presence. When this occurs, the small vehicle may fail to receive the right of way when the traffic light controller skips their phase, such as at traffic lights that are programmed to remain green for the main street and to only service minor movements, such as the side street or the main street left turn lane, on an as-needed basis when there is demand.


title: Traffic light

text: For example, small vehicles may not be detected by an induction loop sensor, such as one whose sensitivity has been set too high in an attempt to avoid false triggers. While a typical motor vehicle has a sufficient mass of metal such as steel that interacts with the sensor's magnetic field, motorcycles and scooters have much less mass than cars, and bicycles may not even be constructed with metal. This situation most often occurs at times of day when other traffic is sparse as well as when the small vehicle is coming from a direction that does not have a high volume of traffic.


title: Traffic light

text: There are significant differences from place to place in how traffic lights are mounted or positioned so that they are visible to drivers. Depending upon the location, traffic lights may be mounted on poles situated on street corners, hung from horizontal poles or wires strung over the roadway, or installed within large horizontal gantries that extend out from the corner and over the right-of-way. In the last case, such poles or gantries often have a lit sign with the name of the cross-street.


title: Traffic light

text: In some locations, lights are mounted with their multiple faces arranged horizontally, often with supplemental vertical signals on the side, while other locations use vertical signals almost exclusively. Horizontal signals have consistent orientation, like their vertical counterparts. Often, supplemental curb pedestal mounts, intended to support a signal for a different approach road, are used when primary signals are partially obscured due to structures such as overpasses, approaches around a building that obscures the primary signal mountings, and unusual approach geometry. In Florida, horizontal signals mounted on poles, known as "mast arms", are in wide use due to their lower wind profile, important for minimizing hurricane damage. In areas where wind-load is not as much of a concern as ice-load, such as Illinois or Minnesota, the lights are mounted vertically to reduce the accumulation of ice or snow over the surface of the signal heads. In a few countries such as Mexico and a few provinces in Canada such as New Brunswick, most traffic signals are mounted horizontally.


title: Traffic light

text: Traffic signals in most areas of Europe are located at the stop line on the same side of the intersection as the approaching traffic (there being both right- and left-hand traffic) and are often mounted overhead as well as on side of the road. At particularly busy junctions for freight, higher lights may be mounted specifically for trucks. The stop line alignment is done to prevent vehicles from blocking any crosswalk and allow for better pedestrian traffic flow. There may also be a special area a few meters in advance of the stop line where cyclists may legally wait but not motor vehicles; this advanced stop line is often painted with a different road surface with greater friction and high colour, both for the benefit of cyclists and for other vehicles. The traffic lights are mounted so that cyclists can still see them.


title: Traffic light

text: In Spain, the mounted traffic lights on the far side of the intersection are meant for the traffic that exits the intersection in that particular direction. This is often done due to the pedestrian crossings, so that traffic has to wait if they get a red light. These intersections also come with a stop line in the exit area of the intersection.


title: Traffic light

text: In North America, there is often a pole-mounted signal on the same side of the intersection, but additional pole-mounted and overhead signals are usually mounted on the far side of the intersection for better visibility. Most traffic lights are mounted that way in the Western United States and Canada. In Ontario, traffic lights are almost always mounted on the far side of the intersection with poles.


title: Traffic light

text: In some areas of the United States, signals facing in up to four directions are hung directly over the intersection on a wire strung diagonally over the intersection (once common in Michigan), or the signal faces traffic in one direction, still hung by wires (but the wire is strung horizontally between two adjacent corners of the intersection). This is common in the Southern and Eastern United States.


title: Traffic light

text: Dummy lights are traffic signs located in the centre of a junction, which operate on a fixed cycle. These have generally been decommissioned due to safety concerns; however, a number remain due to historic value.


title: Traffic light

text: In other countries including the United Kingdom, Australia, New Zealand, South Africa, and Lebanon, traffic lights are mounted at the stop line before the intersection and also after the intersection. Some busy intersections have an overhead traffic light for heavy vehicles and vehicles further away.


title: Traffic light

text: Traffic lights can increase the traffic capacity at intersections and reduce delay for side road traffic, but can also result in increased delay for main road traffic. Hans Monderman, the innovative Dutch traffic engineer, and pioneer of shared space schemes, was sceptical of their role, and is quoted as having said of them: "We only want traffic lights where they are useful and I haven't found anywhere where they are useful yet."


title: Traffic light

text: A World Economic Forum study found that signalised junctions are linked to higher rates of localised air pollution. Drivers accelerate and stop frequently at lights and as such peak particle concentration can be around 29 times higher than during free-flow conditions. The WEF recommends that traffic authorities synchronise traffic signals, consider alternative traffic management systems and consider placing traffic lights away from residential areas, schools, and hospitals.


title: Traffic light

text: The separation of conflicting streams of traffic in time can reduce the chances of right-angle collisions by turning traffic and cross traffic, but they can increase the frequency of rear-end crashes by up to 50%. Since right-angled and turn-against-traffic collisions are more likely to result in injuries, this is often an acceptable trade-off. They can also adversely affect the safety of bicycle and pedestrian traffic.


title: Traffic light

text: Between 1979 and 1988, the city of Philadelphia, Pennsylvania, removed signals at 199 intersections that were not warranted. On average, the intersections had 24% fewer crashes after the unwarranted signals were removed. The traffic lights had been erected in the 1960s because of since-resolved protests over traffic. By 1992, over 800 traffic lights had been removed at 426 intersections, and the number of crashes at these intersections dropped by 60%.


title: Traffic light

text: Criteria have been developed to help ensure that new traffic lights are installed only where they will do more good than harm and to justify the removal of existing traffic lights where they are not warranted. They are most often placed on arterial roads at intersections with either another arterial road or a collector road, or on an expressway where an interchange is not warranted. In some situations, traffic signals can also be found on collector roads in busy settings.


title: Traffic light

text: In the United States, the criteria for installation of a traffic control signal are prescribed by the Manual on Uniform Traffic Control Devices (MUTCD), which defines the criteria in nine "warrants":


title: Traffic light

text: An intersection is usually required to meet one or more of these warrants before a signal is installed. However, meeting one or more warrants does not require the installation of a traffic signal, it only suggests that they may be suitable. It could be that a roundabout would work better. There may be other unconsidered conditions that lead traffic engineers to conclude that a signal is undesirable. For example, it may be decided not to install a signal at an intersection if traffic stopped by it will back up and block another, more heavily trafficked intersection. Also, if a signal meets only the peak hour warrant, the advantages during that time may not outweigh the disadvantages during the rest of the day.


title: Traffic light

text: In virtually all jurisdictions in which they are used, it is an offence for motorists (and other road users) to disobey traffic control devices, such as traffic lights.


title: Traffic light

text: In some jurisdictions (such as New York City), there are ordinances or by-laws against "gridlocking". A motorist entering an intersection (even if on a green light) but unable to proceed and who gets stranded in the intersection (when traffic ahead fails to proceed), and who remains after the light turns red (thus blocking traffic from other directions) may be cited. The definition of the intersection area is a square where the two streets overlap marked by the inner lines of each crosswalk. (Occupying the space inside the crosswalk lines is itself a traffic infraction, but different from gridlocking.) This gives meaning to the anti-gridlock slogan "don't block the box". This is sometimes used as a justification for making a turn across the opposing travel lanes on a red light at a busy intersection, by pulling partway into the intersection at a green light waiting to perform the turn, and, if oncoming traffic is not abated before the light changes to red, proceeding to turn once the light has turned red and opposing traffic has stopped. This means that at busy junctions without a protected green arrow for turning traffic, one turns after the light turns red. This maneuver is commonly referred to as "occupying the intersection" or "being legally allowed to complete one's turn". In some jurisdictions, including most American states, a vehicle already in the intersection when the light turns red legally has the right of way, and vehicles who have green must yield to the vehicle in the intersection.


title: Traffic light

text: In Sackville, New Brunswick, it is customary for through traffic to voluntarily yield to the first oncoming left-turning vehicle to allow it to perform a "Pittsburgh left" manoeuvre. This is similar to a hook turn performed in Melbourne, Australia, which is legal at signed intersections.


title: Traffic light

text: Red light running occurs when a motorist enters a junction any time after the signal light turns red unless a legal turn on red manoeuvre is completed. A US national survey in 2019 found that 86% of drivers thought it was very dangerous to run a red light at speed, but 31% reported that they had done so in the past 30 days.


title: Traffic light

text: Common reasons for red light running include inattentive driving, following an oversized vehicle, or during inclement weather. Drivers are more likely to run red lights during peak traffic hours or if the signal is on a downward slope.Uber had to apologise in 2016 after a self-driving Uber vehicle ran a red light "due to human error" in San Francisco. Red light runners involved in multiple-vehicle crashes are more likely male, younger, involved in prior crashes, or have alcohol-impaired driving convictions. According to the IIHS Insurance Institute for Highway Safety, every year red light running causes hundreds of deaths, thousands of injuries, and hundreds of millions of dollars in related costs.


title: Traffic light

text: In Spring 2015, Hunter College in New York City completed an observational study of red light running, the first of its kind. The conclusion, after monitoring 3,259 vehicles at 50 intersections over a period of days around the 5 boroughs, found that almost 10% of vehicles and 15% of taxis ran the red light, amounting to nearly 400,000 red lights run every single day.


title: Traffic light

text: Red light running can be deterred through enforcement or engineering strategies. It is normally illegal and may incur a fine, demerit points, or a stricter sentence. As of 2021, Norway has the highest fine in Europe for red light running at €756 equivalent. The US Federal Highway Administration recommends that engineers:


title: Traffic light

text: After the Hunter College study, New York City Mayor Bill de Blasio launched a Vision Zero plan to reduce vehicular and pedestrian fatalities. The New York City Police Department's 2014 TrafficStat report showed 33,577 red light tickets for 2013, which is a 126% increase in the number of failure-to-yield summonses and red-light running violations.


title: Traffic light

text: In some countries, red light cameras are used for either the driver or the vehicle's owner. An automated camera is connected to the triggering mechanism for the corresponding traffic light, which is programmed to photograph a vehicle and driver crossing against the light. Either the driver or the vehicle's owner (depending on the locale) are fined for the violation. In some jurisdictions, including the United States and Italy, private companies have been contracted to operate traffic-related cameras and receive a portion of the resulting revenues. In some cases, red light cameras have been abused by local governments, where vehicle operators have been fined as a result of traffic systems that have been improperly modified. Despite the fact that cameras can reduce the number of crashes, it has been proven that at these intersections drivers tended to react quicker to an amber light change when stopping. The consequence of this change could be a slight decline in the intersection capacity.


title: Traffic light

text: Red light cameras in New South Wales, Australia, are activated only if a motorist enters an intersection 0.3 seconds after the light has turned red.


title: Traffic light

text: In some jurisdictions, yellow light running may also be illegal, unless a driver cannot stop before the stop line safely. For example, this rule is in place in states within Australia, Russia (which also has a flashing green phase and possibly countdown timers to warn drivers of a yellow phase), and the UK.


title: Traffic light

text: The "Amber Gambler Twins" is one of many public interest films trying to change the public's behaviour regarding the running of yellow lights.


title: Traffic light

text: Another way police officers have begun to combat red light runners is with blue or white "Confirmation Lights". These lights can be seen from any angle in an intersection and are typically utilised by emergency responders who actuate traffic signal preemption devices to verify that other motorists are facing a red signal. However, confirmation lights also assist officers – who do not have to have a line of sight with a red light – to catch vehicles illegally entering an intersection. They are only lit when the red light on the same signal head is on. Some intersections will also have multiple confirmation lights for a single direction of travel if there are different signals for different directions. These lights are separate from the main ones, often protruding above or below the main traffic light, and are much smaller than a standard light to help avoid confusion.


title: Traffic light

text: In the Netherlands, many red traffic signals can be seen from the side via a small bulbous window, indicating to drivers (and police officers) whether the signal in the crossing direction is actually red or not, by simply leaking out some of the red light through the side of the traffic signal. This has gradually become less common as traditional incandescent signals are replaced by LED signals, while increasingly red light cameras are used to detect driving-through-red violations.


title: Traffic light

text: The length of yellow lights can differ, for example in many places the length of a yellow light is usually four or five seconds, but elsewhere it may be as little as three, considerably reducing the time for reaction. It is typical for these times to vary according to the set speed limit, with longer times for higher limits. In the U.S. state of Georgia, an amber light must be lit one second for every of the posted speed limit. For intersections with red light cameras, one extra second must be added. In Colorado Springs, Colorado, amber lights at numerous intersections have been noted with durations of approximately two seconds. In the United States, there is a recommended federal safety minimum of three seconds for amber lights.


title: Traffic light

text: The time between when a red light is displayed and when a cross street is given a green light is usually based on the physical size of the intersection. This intervening period is called the "all-red time". A typical all-red time is two seconds to allow cars to clear the intersection. In a wider intersection, such as a four-lane road or highway intersection, the all-red time may be as much as five seconds, allowing drivers who could not or would not stop at the amber light enough time to clear the intersection without causing a collision. Two exceptions are in New Westminster, British Columbia, Canada, and Winnipeg, Manitoba, Canada, where there is no all-red time. The change is instantaneous, due to the nature of the older relay-operated signals. It is also the case in Montreal, Quebec, Canada.


title: Traffic light

text: The symbolism of a traffic light (and the meanings of the three primary colours used in traffic lights) are frequently found in many other contexts. Since they are often used as single spots of colour without the context of vertical position, they are typically not comprehensible to up to one in ten males who are colour blind.


title: Traffic light

text: Traffic lights have also been used in computer software, such as the macOS user interface, and in pieces of artwork, particularly the Traffic Light tree in London, UK.


title: Traffic light

text: Automobile racing circuits can also use standard traffic signals to indicate to racing car drivers the status of racing. On an oval track, four sets may be used, two facing a straight-away and two facing the middle of the 180-degree turn between straight-away. Green would indicate racing is underway, while amber would indicate to slow or while following a pace car; red would indicate to stop, probably for emergency reasons.


title: Traffic light

text: Scuderia Ferrari, a Formula One racing team, formerly used a traffic light system during their pit stops to signal to their drivers when to leave the pits. The red light was on when the tires were being changed and fuel was being added, amber was on when the tires were changed, and green was on when all work was completed. The system is (usually) completely automatic. However, the system was withdrawn after the 2008 Singapore Grand Prix, due to the fact that it heavily delayed Felipe Massa during the race, when he was in the lead. Usually, the system was automatic, but heavy traffic in the pit lane forced the team to operate it manually. A mechanic accidentally pressed the green light button when the fuel hose was still attached to the car, causing Massa to drive off, towing the fuel hose along. Additionally, Massa drove into the path of Adrian Sutil, earning him a penalty. He finally stopped at the end of the pit lane, forcing Ferrari's mechanics to sprint down the whole of the pit lane to remove the hose. As a result of this, and the penalty he also incurred, Massa finished 13th. Ferrari decided to use a traditional "lollipop" for the remainder of the 2008 season.


title: Traffic light

text: Another type of traffic light that is used in racing is the Christmas Tree, which is used in drag racing. The Christmas Tree has six lights: a blue staging light, three amber lights, a green light, and a red light. The blue staging light is divided into two parts: Pre-stage and stage. Sometimes, there are two sets of bulbs on top of each other to represent them. Once a driver is staged at the starting line, then the starter will activate the light to commence racing, which can be done in two ways. If a Pro tree is used, then the three amber lights will flash at the same time. For the Sportsman tree, the amber light will flash from top to bottom. When the green light comes up, the race officially begins but if a driver crosses the line before that happens, then a red light will come up and that will be a foul.


title: Traffic light

text: The colours red, yellow, and green are often used as a simple-to-understand rating system for products and processes. It may be extended by analogy to provide a greater range of intermediate colours, with red and green at the extremes.


title: Pencil

text: A pencil () is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage, and keeps it from marking the user's hand.


title: Pencil

text: Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which dispense liquid or gel ink onto the marked surface.


title: Pencil

text: Most pencil cores are made of graphite powder mixed with a clay binder. Graphite pencils (traditionally known as "lead pencils") produce grey or black marks that are easily erased, but otherwise resistant to moisture, most chemicals, ultraviolet radiation and natural aging. Other types of pencil cores, such as those of charcoal, are mainly used for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies, especially those with cores made from wax-based binders that tend to smear when erasers are applied to them. Grease pencils have a softer, oily core that can leave marks on smooth surfaces such as glass or porcelain.


title: Pencil

text: The most common pencil casing is thin wood, usually hexagonal in section but sometimes cylindrical or triangular, permanently bonded to the core. Casings may be of other materials, such as plastic or paper. To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point. Mechanical pencils have more elaborate casings which are not bonded to the core; instead, they support separate, mobile pigment cores that can be extended or retracted (usually through the casing's tip) as needed. These casings can be reloaded with new cores (usually graphite) as the previous ones are exhausted.


title: Pencil

text: "Pencil", from Old French "pincel", from Latin a "little tail" (see "penis"; "pincellus" is Latin from the post-classical period) originally referred to an artist's fine brush of camel hair, also used for writing before modern lead or chalk pencils.


title: Pencil

text: Though the archetypal pencil was an artist's brush, the stylus, a thin metal stick used for scratching in papyrus or wax tablets, was used extensively by the Romans and for palm-leaf manuscripts.


title: Pencil

text: As a technique for drawing, the closest predecessor to the pencil was silverpoint or leadpoint until in 1565 (some sources say as early as 1500), a large deposit of graphite was discovered on the approach to Grey Knotts from the hamlet of Seathwaite in Borrowdale parish, Cumbria, England. This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. It remains the only large-scale deposit of graphite ever found in this solid form. Chemistry was in its infancy and the substance was thought to be a form of lead. Consequently, it was called "plumbago" (Latin for "lead ore"). Because the pencil core is still referred to as "lead", or "a lead", many people have the misconception that the graphite in the pencil is lead, and the black core of pencils is still referred to as "lead", even though it never contained the element lead. The words for pencil in German ("Bleistift"), Irish ("peann luaidhe"), Arabic (قلم رصاص "qalam raṣāṣ"), and some other languages literally mean "lead pen".


title: Pencil

text: The value of graphite would soon be realised to be enormous, mainly because it could be used to line the moulds for cannonballs; the mines were taken over by the Crown and were guarded. When sufficient stores of graphite had been accumulated, the mines were flooded to prevent theft until more was required.


title: Pencil

text: The usefulness of graphite for pencils was discovered as well, but graphite for pencils had to be smuggled. Because graphite is soft, it requires some form of encasement. Graphite sticks were initially wrapped in string or sheepskin for stability. England would enjoy a monopoly on the production of pencils until a method of reconstituting the graphite powder was found in 1662 in Germany. However, the distinctively square English pencils continued to be made with sticks cut from natural graphite into the 1860s. The town of Keswick, near the original findings of block graphite, still manufactures pencils, the factory also being the location of the Derwent Pencil Museum. The meaning of "graphite writing implement" apparently evolved late in the 16th century.


title: Pencil

text: Around 1560, an Italian couple named Simonio and Lyndiana Bernacotti made what are likely the first blueprints for the modern, wood-encased carpentry pencil. Their version was a flat, oval, more compact type of pencil. Their concept involved the hollowing out of a stick of juniper wood. Shortly thereafter, a superior technique was discovered: two wooden halves were carved, a graphite stick inserted, and the halves then glued together—essentially the same method in use to this day.


title: Pencil

text: The first attempt to manufacture graphite sticks from powdered graphite was in Nuremberg, Germany, in 1662. It used a mixture of graphite, sulphur, and antimony.


title: Pencil

text: English and German pencils were not available to the French during the Napoleonic Wars; France, under naval blockade imposed by Great Britain, was unable to import the pure graphite sticks from the British Grey Knotts mines – the only known source in the world. France was also unable to import the inferior German graphite pencil substitute. It took the efforts of an officer in Napoleon's army to change this. In 1795, Nicolas-Jacques Conté discovered a method of mixing powdered graphite with clay and forming the mixture into rods that were then fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied. This method of manufacture, which had been earlier discovered by the Austrian Joseph Hardtmuth, the founder of the Koh-I-Noor in 1790, remains in use. In 1802, the production of graphite leads from graphite and clay was patented by the Koh-I-Noor company in Vienna.


title: Pencil

text: In England, pencils continued to be made from whole sawn graphite. Henry Bessemer's first successful invention (1838) was a method of compressing graphite powder into solid graphite thus allowing the waste from sawing to be reused.


title: Pencil

text: American colonists imported pencils from Europe until after the American Revolution. Benjamin Franklin advertised pencils for sale in his "Pennsylvania Gazette" in 1729, and George Washington used a three-inch pencil when he surveyed the Ohio Country in 1762. William Munroe, a cabinetmaker in Concord, Massachusetts, made the first American wood pencils in 1812. This was not the only pencil-making occurring in Concord. According to Henry Petroski, transcendentalist philosopher Henry David Thoreau discovered how to make a good pencil out of inferior graphite using clay as the binder; this invention was prompted by his father's pencil factory in Concord, which employed graphite found in New Hampshire in 1821 by Charles Dunbar.


title: Pencil

text: Munroe's method of making pencils was painstakingly slow, and in the neighbouring town of Acton, a pencil mill owner named Ebenezer Wood set out to automate the process at his own pencil mill located at Nashoba Brook. He used the first circular saw in pencil production. He constructed the first of the hexagon- and octagon-shaped wooden casings. Ebenezer did not patent his invention and shared his techniques with anyone. One of those was Eberhard Faber, which built a factory in New York and became the leader in pencil production.


title: Pencil

text: Joseph Dixon, an inventor and entrepreneur involved with the Tantiusques graphite mine in Sturbridge, Massachusetts, developed a means to mass-produce pencils. By 1870, The Joseph Dixon Crucible Company was the world's largest dealer and consumer of graphite and later became the contemporary Dixon Ticonderoga pencil and art supplies company.


title: Pencil

text: By the end of the 19th century, over 240,000 pencils were used each day in the US. The favoured timber for pencils was Red Cedar as it was aromatic and did not splinter when sharpened. In the early 20th century supplies of Red Cedar were dwindling so that pencil manufacturers were forced to recycle the wood from cedar fences and barns to maintain supply.


title: Pencil

text: One effect of this was that "during World War II rotary pencil sharpeners were outlawed in Britain because they wasted so much scarce lead and wood, and pencils had to be sharpened in the more conservative manner – with knives."


title: Pencil

text: It was soon discovered that incense cedar, when dyed and perfumed to resemble Red Cedar, was a suitable alternative. Most pencils today are made from this timber, which is grown in managed forests. Over 14 billion pencils are manufactured worldwide annually. Less popular alternatives to cedar include basswood and alder.


title: Pencil

text: In Southeast Asia, the wood Jelutong may be used to create pencils (though the use of this rainforest species is controversial). Environmentalists prefer the use of Pulai – another wood native to the region in pencil manufacturing.


title: Pencil

text: On March 30, 1858, Hymen Lipman received the first patent for attaching an eraser to the end of a pencil. In 1862, Lipman sold his patent to Joseph Reckendorfer for $100,000, who went on to sue pencil manufacturer Faber-Castell for infringement. In "Reckendorfer v. Faber" (1875), the Supreme Court of the United States ruled against Reckendorfer, declaring the patent invalid.


title: Pencil

text: Historian Henry Petroski notes that while ever more efficient means of mass production of pencils has driven the replacement cost of a pencil down, before this people would continue to use even the stub of a pencil. For those who did not feel comfortable using a stub, pencil extenders were sold. These devices function something like a "porte-crayon"...the pencil stub can be inserted into the end of a shaft...Extenders were especially common among engineers and draftsmen, whose favorite pencils were priced dearly. The use of an extender also has the advantage that the pencil does not appreciably change its heft as it wears down." Artists use extenders to maximize the use of their colored pencils.


title: Pencil

text: Graphite pencils are the most common types of pencil, and are encased in wood. They are made of a mixture of clay and graphite and their darkness varies from light grey to black. Their composition allows for the smoothest strokes.


title: Pencil

text: Solid graphite pencils are solid sticks of graphite and clay composite (as found in a 'graphite pencil'), about the diameter of a common pencil, which have no casing other than a wrapper or label. They are often called "woodless" pencils. They are used primarily for art purposes as the lack of casing allows for covering larger spaces more easily, creating different effects, and providing greater economy as the entirety of the pencil is used. They are available in the same darkness range as wood-encased graphite pencils.


title: Pencil

text: Liquid graphite pencils are pencils that write like pens. The technology was first invented in 1955 by Scripto and Parker Pens. Scripto's liquid graphite formula came out about three months before Parker's liquid lead formula. To avoid a lengthy patent fight the two companies agreed to share their formulas.


title: Pencil

text: Charcoal pencils are made of charcoal and provide fuller blacks than graphite pencils, but tend to smudge easily and are more abrasive than graphite. Sepia-toned and white pencils are also available for duotone techniques.


title: Pencil

text: Carbon pencils are generally made of a mixture of clay and lamp black, but are sometimes blended with charcoal or graphite depending on the darkness and manufacturer. They produce a fuller black than graphite pencils, are smoother than charcoal, and have minimal dust and smudging. They also blend very well, much like charcoal.


title: Pencil

text: Colored pencils, or pencil crayons, have wax-like cores with pigment and other fillers. Several colors are often blended together.


title: Pencil

text: Grease pencils can write on virtually any surface (including glass, plastic, metal and photographs). The most commonly found grease pencils are encased in paper (Berol and Sanford Peel-off), but they can also be encased in wood (Staedtler Omnichrom).


title: Pencil

text: Watercolor pencils are designed for use with watercolor techniques. Their cores can be diluted by water. The pencils can be used by themselves for sharp, bold lines. Strokes made by the pencil can also be saturated with water and spread with brushes.


title: Pencil

text: Carpenter's pencils are pencils that have two main properties: their shape prevents them from rolling, and their graphite is strong. The oldest surviving pencil is a German carpenter's pencil dating from the 17th Century and now in the Faber-Castell collection.


title: Pencil

text: Copying pencils (or indelible pencils) are graphite pencils with an added dye that creates an indelible mark. They were invented in the late 19th century for press copying and as a practical substitute for fountain pens. Their markings are often visually indistinguishable from those of standard graphite pencils, but when moistened their markings dissolve into a coloured ink, which is then pressed into another piece of paper. They were widely used until the mid-20th century when ball pens slowly replaced them. In Italy their use is still mandated by law for voting paper ballots in elections and referendums.


title: Pencil

text: Eyeliner pencils are used for make-up. Unlike traditional copying pencils, eyeliner pencils usually contain non-toxic dyes.


title: Pencil

text: Unlike wax-based colored pencils, the erasable variants can be easily erased. Their main use is in sketching, where the objective is to create an outline using the same color that other media (such as wax pencils, or watercolor paints) would fill or when the objective is to scan the color sketch. Some animators prefer erasable color pencils as opposed to graphite pencils because they do not smudge as easily, and the different colors allow for better separation of objects in the sketch. Copy-editors find them useful too as markings stand out more than those of graphite, but can be erased.


title: Pencil

text: Also known as non-photo blue pencils, the non-reproducing types make marks that are not reproducible by photocopiers (examples include "Copy-not" by Sanford and "Mars Non-photo" by Staedtler) or by whiteprint copiers (such as "Mars Non-Print" by Staedtler).


title: Pencil

text: Stenographer's pencils, also known as a steno pencil, are expected to be very reliable, and their lead is break-proof. Nevertheless, steno pencils are sometimes sharpened at both ends to enhance reliability. They are round to avoid pressure pain during long texts.


title: Pencil

text: Golf pencils are usually short (a common length is ) and very cheap. They are also known as library pencils, as many libraries offer them as disposable, leak-proof writing instruments.


title: Pencil

text: A standard, hexagonal, "#2 pencil" is cut to a hexagonal height of , but the outer diameter is slightly larger (about )


title: Pencil

text: On 3 September 2007, Ashrita Furman unveiled his giant US$20,000 pencil – long, (with over for the graphite centre) – after three weeks of creation in August 2007 as a birthday gift for teacher Sri Chinmoy. It is longer than the pencil outside the Malaysia HQ of stationers Faber-Castell.


title: Pencil

text: Mechanical pencils use mechanical methods to push lead through a hole at the end. These can be divided into two groups: with propelling pencils an internal mechanism is employed to push the lead out from an internal compartment, while clutch pencils merely hold the lead in place (the lead is extended by releasing it and allowing some external force, usually gravity, to pull it out of the body). The erasers (sometimes replaced by a sharpener on pencils with larger lead sizes) are also removable (and thus replaceable), and usually cover a place to store replacement leads. Mechanical pencils are popular for their longevity and the fact that they may never need sharpening. Lead types are based on grade and size; with standard sizes being , , , , , , , , and (ISO 9175-1)—the size is available, but is not considered a standard ISO size.


title: Pencil

text: Pioneered by Taiwanese stationery manufacturer Bensia Pioneer Industrial Corporation in the early 1970s, Pop a Point Pencils are also known as Bensia Pencils, stackable pencils or non-sharpening pencils. It is a type of pencil where many short pencil tips are housed in a cartridge-style plastic holder. A blunt tip is removed by pulling it from the writing end of the body and re-inserting it into the open-ended bottom of the body, thereby pushing a new tip to the top.


title: Pencil

text: Invented by Harold Grossman for the Empire Pencil Company in 1967, plastic pencils were subsequently improved upon by Arthur D. Little for Empire from 1969 through the early 1970s; the plastic pencil was commercialised by Empire as the "EPCON" Pencil. These pencils were co-extruded, extruding a plasticised graphite mix within a wood-composite core.


title: Pencil

text: Although lead has not been used for writing since antiquity, such as in Roman styli, lead poisoning from pencils was not uncommon. Until the middle of the 20th century the paint used for the outer coating could contain high concentrations of lead, and this could be ingested when the pencil was sucked or chewed.


title: Pencil

text: The lead of the pencil is a mix of finely ground graphite and clay powders. Before the two substances are mixed, they are separately cleaned of foreign matter and dried in a manner that creates large square cakes. Once the cakes have fully dried, the graphite and the clay squares are mixed together using water. The amount of clay content added to the graphite depends on the intended pencil hardness (lower proportions of clay makes the core softer), and the amount of time spent on grinding the mixture determines the quality of the lead. The mixture is then shaped into long spaghetti-like strings, straightened, dried, cut, and then tempered in a kiln. The resulting strings are dipped in oil or molten wax, which seeps into the tiny holes of the material and allows for the smooth writing ability of the pencil. A juniper or incense-cedar plank with several long parallel grooves is cut to fashion a "slat," and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole assembly is then cut into individual pencils, which are then varnished or painted. Many pencils feature an eraser on the top and so the process is usually still considered incomplete at this point. Each pencil has a shoulder cut on one end of the pencil to allow for a metal ferrule to be secured onto the wood. A rubber plug is then inserted into the ferrule for a functioning eraser on the end of the pencil.


title: Pencil

text: Graphite pencils are made of a mixture of clay and graphite and their darkness varies from light grey to black: the more clay the harder the pencil. There is a wide range of grades available, mainly for artists who are interested in creating a full range of tones from light grey to black. Engineers prefer harder pencils which allow for a greater control in the shape of the lead.


title: Pencil

text: Manufacturers distinguish their pencils by grading them, but there is no common standard. Two pencils of the same grade but different manufacturers will not necessarily make a mark of identical tone nor have the same hardness.


title: Pencil

text: Most manufacturers, and almost all in Europe, designate their pencils with the letters "H" (commonly interpreted as "hardness") to "B" (commonly "blackness"), as well as "F" (usually taken to mean "fineness", although F pencils are no more fine or more easily sharpened than any other grade. Also known as "firm" in Japan). The standard writing pencil is graded "HB". This designation was in use at least as early as 1844. It used "B" for black and "H" for hard; a pencil's grade was described by a sequence or successive Hs or Bs such as "BB" and "BBB" for successively softer leads, and "HH" and "HHH" for successively harder ones. The Koh-i-Noor Hardtmuth pencil manufacturers claim to have first used the HB designations, with "H" standing for Hardtmuth, "B" for the company's location of Budějovice, and "F" for Franz Hardtmuth, who was responsible for technological improvements in pencil manufacture.


title: Pencil

text: As of 2021, a set of pencils ranging from a very soft, black-marking pencil to a very hard, light-marking pencil usually ranges from softest to hardest as follows:


title: Pencil

text: Koh-i-noor offers twenty grades from 10H to 8B for its 1500 series. Mitsubishi Pencil offers twenty-two grades from 10H to 10B for its Hi-uni range. Derwent produces twenty grades from 9H to 9B for its graphic pencils. Staedtler produces 24 from 10H to 12B for its Mars Lumograph pencils.


title: Pencil

text: Numbers as designation were first used by Conté and later by John Thoreau, father of Henry David Thoreau, in the 19th century.


title: Pencil

text: Although Conté/Thoreau's equivalence table is widely accepted, not all manufacturers follow it; for example, Faber-Castell uses a different equivalence table in its "Grip 2001" pencils: 1 = 2B, 2 = B, 2½ = HB, 3 = H, 4 = 2H.


title: Pencil

text: Graded pencils can be used for a rapid test that provides relative ratings for a series of coated panels but can't be used to compare the pencil hardness of different coatings. This test defines a "pencil hardness" of a coating as the grade of the hardest pencil that does not permanently mark the coating when pressed firmly against it at a 45 degree angle. For standardized measurements, there are Mohs hardness testing pencils on the market.