Traffic sign

From Exampleproblems

Most countries place signs, known as traffic signs or road signs, at the side of roads to impart information to road users. Since language differences can create barriers to understanding, international signs using symbols in place of words have been developed in Europe and adopted in most countries and areas of the world. Annexe 1 of the Vienna Convention on Road Signs and Signals of November 8, 1968 defines eight categories of signs:

• A. Danger warning signs
• B. Priority signs
• C. Prohibitory or restrictive signs
• D. Mandatory signs
• E. Special regulation signs
• F. Information, facilities, or service signs
• G. Direction, position, or indication signs
• H. Additional panels

However, countries and areas categorize road signs in different ways. In the U.S., the type, placement, and graphic standards of traffic signs and pavement markings are legally regulated — the Federal Highway Administration's Manual on Uniform Traffic Control Devices is the standard, although each state produces their own manual based upon the Federal manual.

History

The earliest road signs gave directions; for example, the Romans erected stone columns throughout their empire giving the distance to Rome. In the Middle Ages multidirectional signs at intersections became common, giving directions to cities and towns.

Traffic signs became more important with the development of automobiles. The basic patterns of most traffic signs were set at the 1908 International Road Congress in Rome. Since then there have been considerable change. Today they are almost all metal rather than wood and are coated with retroreflective sheetings of various types for nighttime and low-light visibility.

New generations of traffic signs based on big electronic displays can also change its symbols and also provide intelligent behavior by means of sensors or by remote control. In this sense, "road beacons" or RBS based in the use of RFID special transponders buried in the asphalt arise as an innovative evolution for on-board signalling.

Categorization

United States of America

• Regulatory signs
• Warning signs
• Guide signs
  • Route marker signs
  • Expressway signs
  • Freeway signs
  • Informational signs
  • Recreational and cultural interest signs
• Emergency management (civil defense) signs
• Temporary traffic control (construction or work zone) signs
• School signs
• Railroad and light rail signs
• Bicycle signs

Design

North America and Australia

Color schemes

In North America and Australia, signs generally adhere to the following colours:

• green with white letters for informational signs, such as directions, distances, and places
• brown with white for signs to parks, historic sites, ski areas, forests, and campgrounds
• blue with white for rest areas, food, gasoline or petrol, and lodging
• white with red or black letters for regulatory signs, such as speed limits or parking
• yellow with black letters and symbols for warning signs, such as curves and school zones
• orange with black letters for temporary traffic control zones and detours

Regulatory signs are also sometimes seen with white letters on red or black signs. In Quebec, the usage of blue and brown is reversed, and many black-on-yellow signs are red-on-white instead. Many U.S. states now use fluorescent orange for construction signs, and fluorescent yellow-green (FYG) for school zone, crosswalk, pedestrian, and bicycle warning signs. Fluorescent pink signs are sometimes used for incident management warning.

Highway symbols and markers

Every state and province has different markers for its own highways, but use standard ones for all federal highways. Many special highways, such as the Queen Elizabeth Way or Trans-Canada Highway, or originally on U.S. highways like the Dixie Highway, have used unique signs. Counties in the U.S. sometimes use a pentagon-shaped blue sign with yellow letters for numbered county roads, though the use is inconsistent even within states.

Units

American road signs measure distances in miles rather than kilometres. Traffic signs in the United States have been standardized through the Manual on Uniform Traffic Control Devices (MUTCD), though they sometimes still vary from state to state, particularly on older signs.

Languages

Signs in most of Canada, the U.S. and Australia are written in English. Quebec uses French, while New Brunswick uses both English and French and a number of other provinces such as Ontario and Manitoba use bilingual French-English signs in certain localities. Mexico uses Spanish. Within a few miles of the U.S.-Mexico border, road signs are often in English and Spanish.

Typefaces

The typefaces predominantly used on signs in the U.S. are the FHWA alphabet series (Series B through Series F and Series E Modified). Details of letter shape and spacing for these alphabet series are given in "Standard Alphabets for Traffic Control Devices," first published by the Bureau of Public Roads (BPR) in 1945 and subsequently updated by the Federal Highway Administration (FHWA). It is now part of Standard Highway Signs (SHS), the companion volume to the MUTCD which gives full design details for signfaces.

Initially, all of the alphabet series consisted of uppercase letters and digits only, although lowercase extensions were provided for each alphabet series in a 2002 revision of SHS. Current Series B through Series F evolved from identically named alphabet series which were introduced in 1927.

Straight-stroke letters in the 1927 series were substantially similar to their modern equivalents, but unrounded glyphs were used for letters such as B, C, D, etc., to permit more uniform fabrication of signs by illiterate painters. Various state highway departments and the federal BPR experimented with rounded versions of these letters in the following two decades.

The modern, rounded alphabet series were finally standardized in 1945 after rounded versions of some letters (with widths loosely appropriate for Series C or D) were specified as an option in the 1935 MUTCD and draft versions of the new typefaces had been used in 1942 for guide signs on the newly constructed Pentagon road network.

The mixed-case alphabet now called Series E Modified, which is the standard for destination legend on freeway guide signs, originally existed in two parts: an all-uppercase Series E Modified, which was essentially similar to Series E except for a larger stroke width, and a lowercase-only alphabet. Both parts were developed by the California Division of Highways (now Caltrans) for use on freeways in 1948-50.

Initially the Division used all-uppercase Series E Modified for button-reflectorized letters on ground-mounted signs and mixed-case legend (lowercase letters with Series D capitals) for externally illuminated overhead guide signs. Several Eastern turnpike authorities blended all-uppercase Series E Modified with the lowercase alphabet for destination legends on their guide signs.

Eventually this combination was accepted for destination legend in the first manual for signing Interstate highways, which was published in 1958 by the American Association of State Highway Officials (AASHO) and adopted as the national standard by the BPR.

Uses of Non-FHWA Typefaces

The National Park Service uses Clarendon, a serif typeface, for guide signage (typically, but not always, on a brown background); some states also use Clarendon for recreational signage.

Georgia, in the past, used uppercase Series D with a custom lowercase alphabet on its freeway guide signs; the most distinctive feature of this typeface is the lack of a dot on lowercase 'i' and 'j'.[1] More recent installations appear to include the dots.[2]

A new typeface family titled "Clearview" has been developed by U.S. researchers in recent years to provide improved legibility, and is currently permitted for light legend on dark backgrounds under FHWA interim approval. Thus far, Clearview has only seen widespread use from state departments of transportation in Pennsylvania and Texas.

It is common for local governments, airport authorities, and contractors to fabricate traffic signs using typefaces other than the FHWA series; Arial and Helvetica are common choices.

Europe

In 1968 the Economic Commission for Europe produced a document, intended to unify the use of road signs, signals and road markings "...in order to facilitate international road traffic and to increase road safety". Unfortunately, the document (known as the "1968 Vienna Convention on Road Signs and Signals ") is so open to interpretation that it singularly failed to produce a pan-European standard, instead allowing virtually as many variations as there are countries.

Although there are similarities (most European countries use triangular warning signs, although the background is variously white, yellow or a choice of either) there are regional variations that can prove confusing. Use of the diagonal bar to signify a prohibition is used in some countries on all prohibitory signs, whereas elsewhere they are only used on 'no right turn', 'no left turn' and 'no U-turn' signs.

All EU members currently use the metric system on road signs (distances in kilometres or metres, heights/widths in metres) with the exception of the UK.

Ireland

Main article: Road signs in the Republic of Ireland

Until the partition of Ireland in 1922 and the independence of Southern Ireland (now the Republic of Ireland) British standards applied across the island. In 1926 road sign standards similar to those used in the UK at the time were adopted, albeit with Irish (Gaelic) type in addition to English. In 1956, road signs in the south were changed to markedly differ from the UK standard with the adoption of US-style "diamond" signs for many road hazard warnings (junctions, bends, railway crossings, traffic lights). Some domestic signs were also invented, such as the stay-left sign (a black curved arrow pointing to the upper-left, although these have mostly been replaced by the UK/European 'white arrow on blue disk' signs), while some other signs are not widely adopted outside Ireland, such as the no-entry sign (a black arrow pointing ahead in a white circle with a red slashed circumference).

In January 2005 Ireland adopted metric speed limits. Around 35,000 existing signs were replaced and a further 23,000 new signs erected bearing the speed limit in kilometres per hour. To avoid confusion with the old signs, each speed limit sign now has ‘km/h’ beneath the numerals. See also Roads in Ireland

United Kingdom

Main article: Road signs in the United Kingdom

Traffic signing in the UK conforms broadly to European norms, though a number of signs are unique to Britain and direction signs omit European route numbers. The system currently in use was developed in the late 1950's and early 1960's by the Anderson Committee, which established the motorway signing system, and by the Worboys Committee, which reformed signing for existing all-purpose roads. Older ("pre-Worboys") signs belong to a different system which developed incrementally after 1904, when the Local Government Board first published a circular on traffic signing. The standards governing this system remained of an advisory nature until 1933 when regulations for traffic signs were published under powers created by the Road Traffic Act 1930.

The document governing traffic signing in Britain, comparable to the MUTCD in the United States, is the Traffic Signs Regulations and General Directions (TSRGD). The current signing system was introduced on 1 January 1965 by TSRGD 1964. Britain remains the only European Union member nation to use non-metric (imperial) measurements for distance and speed, although metric authorized-mass signs were prescribed in TSRGD 1981 and there is now a dual-unit (imperial first) option for clearance signing. TSRGD 1994 prescribed a system of white-on-brown direction signs for tourist attractions and also promulgated the Guildford Rules (see below). TSRGD 2002 contains the current standards and includes a sophisticated system of black-on-yellow direction signs for roadworks.

Three separate colour schemes exist for Worboys direction signs and are based on a classification of roads for signing purposes. A road may be a motorway (white on blue), a primary route (white on dark green with yellow route numbers), or a non-primary route (black on white). Most trunk roads, which carry most of the automobile traffic and are owned by central government, and some local authority principal routes are signed as primary routes.

Guildford Rules

A sophisticated system, called the Guildford Rules, is used to put directional information pertaining to routes of different class on patches colored appropriately for those classes on direction signs which have the overall background color appropriate to the roads where they are located. Brown patches, for tourist destinations, can also be added to primary and non-primary route direction signs; however, the Guildford Rules do not apply to roadworks direction signs. This patching system was developed in the mid-1980's as part of an effort to eliminate sign clutter and receives its name from the town of Guildford, Surrey, where the experimental signs were placed.

Example directional sign

The direction sign shown to the right is located near Bristol in England. It is patched according to the Guildford Rules. It gives directions to (Bristol) Parkway railway station (red British Rail symbol), motorways (blue-background patches), and towns reached via non-primary A-roads. Red-edged patches and red-bordered signs are used for military establishments (the Ministry of Defence at Abbey Wood in this example). Destinations which are reached indirectly have the corresponding road number in brackets; for instance, this sign says that Filton is reached by following the A4174 ring road to the A38, and then turning onto the A38 for Filton.

Typefaces

Multiple typefaces are specified for current British road signs. The Transport fonts: Transport Medium (for light text on dark backgrounds) and Transport Heavy (for dark text on light backgrounds), are mixed-case and are used for all legend on fixed permanent signs except route numbers on motorway signs. Two other typefaces, Motorway Permanent (light on dark) and Motorway Temporary (dark on light), are used for route numbers on motorway signs; these have elongated letters and are designed to add emphasis to route numbers on motorways. Transport Medium and Motorway Permanent were developed for the Anderson committee and appeared on the first motorway signs; the other two alphabets are similar but have additional stroke width in the letters to compensate for light backgrounds.

Language

Bilingual signs are used in Wales. Welsh highway authorities choose whether they are "English-priority" or "Welsh-priority" and the language having priority in the highway authority's area appears first on signs. Most of south Wales is English-priority while north Wales is Welsh-priority. Bilingual signs were permitted by special authorization after 1965 and in 1972 the Bowen committee recommended that they should be provided systematically throughout Wales. Bilingual signing in Wales and elsewhere has caused traffic engineers to inquire into the safety ramifications of providing sign legend in multiple languages. As a result some countries have opted to limit bilingual signing to dual-name signs near places of cultural importance (e.g. New Zealand), or to use it only in narrowly circumscribed areas such as near borders or in designated language zones (e.g. the NAFTA countries).

In the Scottish Highlands, road signs often are found with the Scottish Gaelic given (in green) as well as the English (in black). This seems to be part of the Gaelic language revival encouraged by many, including the Bòrd na Gàidhlig.

Central and South America

Road signs in Central and South America vary from country to country. For the most part, conventions in signage tend to resemble North American signage conventions more so than European and Asian conventions. For example, warning signs are typically diamond shaped and yellow rather than triangular and white. Some variations include the "No Parking" sign, which uses a letter 'E' instead of 'P' (the Spanish and Portuguese word for 'Parking' is 'Estacionar'). Notable exceptions include speed limit signs, which follow the European conventions.

Asia

People's Republic of China

Mainland China uses simplified Chinese characters for its traffic signs. It is gradually moving toward internationally-accepted signs; it abandoned, for example, a localised version of the "no parking sign" (with a Hanzi character) and used the blue-red cross sign as of the late 1990s.

In larger cities and on expressways of China, both English and Chinese are used.

Hong Kong Special Administrative Region

Although the mainland uses simplified Chinese characters, traditional Chinese characters are still used in Hong Kong (as the policy of "one country, two systems" allows Hong Kong to maintain most affairs, including road traffic regulations, the way they were prior to the handover).

Most, if not all, of Hong Kong's signs are bilingual, as English and Chinese are considered official languages. English often appears on top of text in traditional Chinese.

Africa

South Africa

South Africa has well developed standards for road signs. Triangular signs are used for warnings and circular signs are used for prohibitions. In the 1990's the colours of these signs were changed from white-on-blue with a red border to black-on-white with a red border. Some regulatory signs that enforce the direction of traffic flow, or minimum speed limits are white on blue.

Informational signs are rectangular and white on green on normal roads and white on blue on freeways. The information on these signs is usually in English, and sometimes in Afrikaans. Other informational signs, such as those that name rivers and towns are white, while tourist information signs are white on brown.

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See also: Street sign theft and traffic light

External links

• http://www.roadbeacon.com/ - Road Beacon System, intelligent traffic signs based on the use of special RFID transponders buried in the pavement.
• http://mutcd.fhwa.dot.gov/ - Manual on Uniform Traffic Control Devices website (Federal Highway Administration)
• http://www.trafficsign.us/ - Manual of Traffic Signs - information on United States signs
• MyRoadSign - Site dedicated to collecting information about road signs
• http://homepages.cwi.nl/~dik/english/traffic/ - Excellent collections of international road traffic signs
• international Convention about traffic sign (governemental Swiss website) in French
• Diamond Signs – extensive image collection of many North American warning signs, including many non-standard and special-purpose signs
• Traffic signs of the world – links, pictures and information about road traffic signs all over the globe
• French traffic signs according to la sécurité routière web site (France) in French
• http://www.unece.org/trans/conventn/legalinst.html - Legal instruments in the field of transport - Number 10 is the Convention on Road Signs and Signals, of 8 November 1968, including the annexes.
• Signs and signals in the European Union
• New York City Department of Transportation Sign Sales
• Traffic Sign Manufacturer in the US. Sells to general public, contractors, and government.de:Verkehrszeichen

es:Señales de tráfico fr:Panneau de signalisation routière he:תמרור nl:Verkeersbord ja:道路標識 pl:Znak drogowy ru:Дорожный знак sco:Traffec sign sv:Vägmärken zh:道路交通標誌