Stop Sign

A stop sign is a traffic sign designed to notify drivers that they must come to a complete stop and make sure the intersection is safely clear of vehicles and pedestrians before continuing past the sign. In many countries, the sign is a red octagon with the word ''STOP'', in either English or the national language of that particular country, displayed in white or yellow. The Vienna Convention on Road Signs and Signals also allows an alternative version: a red circle with a red inverted triangle with either a white or yellow background, and a black or dark blue ''STOP''. Some countries may also use other types, such as Japan's inverted red triangle stop sign. Particular regulations regarding appearance, installation, and compliance with the signs vary by some jurisdiction.

Design and configuration

The 1968 Vienna Convention on Road Signs and Signals allows for two types of stop sign as well as several acceptable variants. Sign B2a is a red octagon with a white legend. The European Annex to the convention also allows the background to be "light yellow". Sign B2b is a red circle with a red inverted triangle with either a white or yellow background, and a black or dark blue legend. The Convention allows for the word "STOP" to be in either English or the national language of the particular country. The finalized version by the United Nations Economic and Social Council's Conference on Road Traffic in 1968 (and in force in 1978) proposed standard stop sign diameters of 600, 900 or 1200 mm.

The United Kingdom and New Zealand stop signs are 750, 900 or 1200 mm, according to sign location and traffic speeds.

In the United States, stop signs are 30 inches (75 cm) across opposite flats of the red octagon, with a -inch (2 cm) white border. The white uppercase legend is 10 inches (25 cm) tall.  Larger signs of 35 inches (90 cm) with 12-inch (30 cm) legend and 1-inch (2.5 cm) border are used on multi-lane expressways. Regulatory provisions exist for extra-large 45-inch (120 cm) signs with 16-inch (40 cm) legend and -inch border for use where sign visibility or reaction distance are limited, and the smallest permissible stop sign size for general usage is 24 inches (60 cm) with an 8-inch (20 cm) legend and -inch (1.5 cm) border. The metric units specified in the US regulatory manuals are rounded approximations of US customary units, not exact conversions.  The field, legend, and border are all retroreflective.

Some modern stop signs have flashing LEDs around the perimeter, which has been shown to substantially reduce crashes.

File:Vienna_Convention_road_sign_B2a.svg, B2a
File:Vienna Convention road sign B2a-EA.svg, Acceptable variant of B2a in the European Annex
File:Vienna Convention road sign B2b-V1.svg, B2b
File:Vienna Convention road sign B2b-V2.svg, Acceptable variant of B2b
File:Vienna Convention road sign B2b-V3.svg, Acceptable variant of B2b
File:Vienna Convention road sign B2b-V4.svg, Acceptable variant of B2b

History

The first ever stop sign was created by Detroit police sergeant Harold "Harry" Jackson, who was working as a traffic guard at a busy city intersection. One of the cross streets had a particularly low-visibility turn entering the intersection, almost always forcing Harry to slow down and hold back the traffic entering from that street. Looking for ways to make his job easier, he took a rectangular piece of plywood, cut off the corners to give it a distinct shape, wrote "STOP" over the center and placed facing the street. He noticed that his innovation improved the overall traffic flow through the intersection. After he shared his experience with fellow officers at a meeting, the practice started to spread across the city intersections.
Next year, stop signs were adopted across Michigan.Signalfan
History of the Stop Sign in America
1997. The first ones had black lettering on a white background and were , somewhat smaller than the current sign. As stop signs became more widespread, a rural-dominated committee supported by the American Association of State Highway Officials (AASHO) met in 1922 to standardize them and selected the octagonal shape that has been used in the United States ever since. The unique eight-sided shape of the sign allows drivers facing the back of the sign to identify that oncoming drivers have a stop sign and prevent confusion with other traffic signs. Another consideration of the AASHO was visibility and driver literacy, as summarized in subsequent State Highway Commission reports in the states of the U.S., was that the goal for signs "standardized throughout the Union" was that "The shape of the sign will indicate what it will mean. This has been worked up very carefully by the best qualified men in the country and men who have made a thorough study of this question. It has been found that so many people have trouble in reading the sign that the shape of the sign is very much more important than the reading matter on it."

The octagon was also chosen so that it could be identified easily at night since the original signs were not reflective. The more urban-oriented National Conference on Street and Highway Safety (NCSHS) advocated a smaller red-on-yellow stop sign. These two organizations eventually merged to form the Joint Committee on Uniform Traffic Control Devices, which in 1935 published the first Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) detailing the stop sign's specifications.

The MUTCD's stop sign specifications were altered eight times between 1935 and 1971. From 1924 to 1954, stop signs bore a red or black legend on a yellow field. Yellow was chosen because fade-resistant red materials were not available. Retro-reflective or self-lit signs were permitted in the 1935 MUTCD; retro-reflective ones were first required by the 1948 edition of the MUTCD, which also called for a height from the road crown to the bottom of the stop sign. The 1954 MUTCD newly specified a white legend on a red field, and increased the mount height specification to 5 feet in rural areas. Red traffic lights signify ''stop'', so the new specification unified red as a stop signal whether given by a sign or a light. The current mounting height of was first specified in 1971.

US mandate, international adoption

The MUTCD stop sign was already widely deployed in the United States when the use of other types of stop signs was eliminated in 1966. In 1968, this sign was adopted by the Vienna Convention on Road Signs and Signals as part of United Nations Economic Commission for Europe's effort to standardize road travel across borders. The Convention specifies that be written in English or the national language, and also allows a circular sign with red legend. Forty European countries are party to the convention.

Stop signs around the world

The red octagonal field with white English-language legend is the most common stop sign used around the world, but it is not universal; Japan uses an inverted solid red triangle, for example, and Zimbabwe until 2016 used a disc bearing a black cross. Moreover, there are many variants of the red-and-white octagonal sign. Although all English-speaking and many other countries use the word on stop signs, some jurisdictions use an equivalent word in their primary language instead, or in addition; the use of native languages is common on U.S. native reservations, especially those promoting language revitalization efforts, for example, and Israel uses no word, but rather a pictogram of a hand in a palm-forward "stop" gesture.

Asia

Countries in Asia generally use a native word, often in a non-Latin script.

Europe

Countries in Europe generally have stop signs with the text , regardless of local language. There were some objections to this when introduced around the 1970s, but now this is accepted. Turkey (and the unrecognized Turkish Republic of Northern Cyprus'')'' is a notable exception to this, instead using the Turkish word for stop: "dur".

Latin America

In Spanish and Portuguese-speaking Caribbean and South American countries (Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, Dominican Republic, Ecuador, Paraguay, Peru, Puerto Rico, Uruguay, and Venezuela), signs bear the legend ("stop" in Portuguese and Spanish). Mexico and Central American countries bear the legend ("halt") instead.

Canada

In the Canadian province of Quebec, modern signs read either or ; however, it is not uncommon to see older signs containing both words in smaller lettering. Both ''stop'' and ''arrêt'' are considered valid French words, with France actually using the word "STOP" on its stop signs, and the Office québécois de la langue française (OQLF) notes that the use of "stop" on stop signs is attested in French since 1927.''panneau ARRÊT''
Office québécois de la langue française, granddictionnaire.com. At the time of the debates surrounding the adoption of the Charter of the French Language ("Bill 101") in 1977, the usage of "stop" was considered to be English and therefore controversial; some signs were occasionally vandalized with red