Road sign
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:
History
Road signs have existed as long as roads have. The earliest signs were ones giving directions. The Romans erected stone columns throughout their empire giving the distance to Rome. In the Middle Ages multidirectional signs at intersections became common giving which city or town lay in each direction.
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. The are also coated in a thin film filled with small glass particles that make them highly reflective.
See also: Street sign theft
