Most countries place signs, known as traffic signs or road signs, at the side of roads to impart information to motorists and other 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. Annex 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
Countries and areas categorize road signs in different ways. The categories used in the United States are:
- Regulatory signs
- Warning signs
- Marker signs
- Guide and informational signs
- Recreational and cultural interest signs
- Signs for bicycle facilities
- Construction signs
- Railroad crossing signs
- School signs
- Civil defense signs
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 much more important with the development of automobiles and their faster motion. The basic patterns of most traffic signs were set at the 1908 International Road Congress in Rome. Since then there have been considerable change in signs. Today there are almost all metal rather than wood and are coated in a thin film filled with small glass particles that make them highly reflective (see retroreflection).
Traffic signs in the United States have been standardized through the Manual on Uniform Traffic Devices (MUTCD). In line with American unilateralism, American road signs tend to be more wordy than their foreign counterparts, use a different color scheme and typeface, and measure distances in miles rather than kilometres.
See also: Street sign theft
External links
- French traffic signs according to la sécurité routière web site (France) in french
- international Convention about traffic sign ( governemental swiss website) 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.
- http://homepages.cwi.nl/~dik/english/traffic/ -- Excellent collections of international road traffic signs
- http://members.aol.com/rcmoeur/signman.html -- Unofficial Manual of Traffic Signs in the United States