We all know what traffic signs are for but are we also familiar with the different categories of traffic signs? According to the Vienna Convention on Road Signs and Signals, traffic signs have eight categories: (1) danger warning signs, (2) priority signs, (3) prohibitory or restrictive signs, (4) mandatory signs, (5) special regulation signs, (6) information, facilities or service signs, (7) direction, position or indication signs, and (8) additional panels.



In the United States, though, the categories, placement, and graphic standards for traffic signs and pavement markings are legally defined in the Federal Highway Administration's Manual on Uniform Traffic Control Devices as the standard.

Historically speaking, the earliest traffic signs were milestones and these were mostly for directional purposes rather than controlling the flow of traffic. The Early Romans erected columns throughout the Roman Empire to give travelers an approximation of how far they are still are from Rome.

However, with the development of automobiles, there arose a need for uniform traffic and other road signs as a means to prevent road accidents. One of the first modern-day road sign systems was devised by the Italian Touring Club in 1895. By 1900, a Congress of the International League of Touring Organizations in Paris was considering proposals for standardization of road signage. Between 1926 and 1949, the intensive work on international road signs led to the development of the European road sign system. It was only in the 1960s when the United States adopted developing its signage system.

Aside from consistency of images, color schemes were also implemented for uniformity. In North America as well as in Australia and New Zealand, the following colors have significant meanings, to wit: * Black/regulation; Blue: road user services guidance, tourist information, and evacuation route; * Brown: recreational and cultural interest area guidance; * Fluorescent Pink: incident management; * Coral: unassigned; * Fluorescent Yellow-Green: pedestrian warning, bicycle warning, playground warning, school bus and school warning; * Green: indicated movements permitted, direction guidance;

* Light Blue/unassigned Orange: temporary traffic control; * Light Blue: unassigned; * Purple: unassigned; * Red: stop or prohibition; * White: regulation; * Yellow: warning

The color code listed above establishes general meanings for 10 colors of a total of 13 colors that have been identified as being appropriate for use in conveying traffic control information. The three colors for which general meanings have not yet been assigned are being reserved for future applications that will be determined only by FHWA after consultation with the States, the engineering community, plus the general public.

Businesses in the US also erect their own traffic signs for their respective establishments. With the growing demand for signage specialists, many companies now offer signage that meet regulations for standard signs including the Manual on Uniform Traffic Control Devices (MUTCD) and US Department of Transportation (DOT) specifications.

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