Purpose: Traffic signals and signs are used for traffic control. They apply to everyone. It provides an orderly and safe flow of traffic.

Traffic Control and Signs

In the United States, road signs are standardized by federal regulations, most notably in the Manual on Uniform Traffic Control Devices (MUTCD) and its companion volume the Standard Highway Signs (SHS).

MUTCD: A document issued by the Federal Highway Administration (FHWA) to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used.

A.   Color and Shape

Red - The use of red on signs is conveys stop, yield, and prohibition signs.

White - White background indicates a regulatory sign; like speed limit.

Yellow - Yellow conveys a general warning message;

Green - Green shows permissible traffic movements or directional guidance;

Fluorescent yellow/green - Fluorescent yellow/green indicates pedestrian crossings and school zones;

Orange - Orange is used for warning and guidance in roadway work zones;

Blue - Blue indicates road user services, tourist information, and evacuation routes; and

Brown is for guidance to sites of public recreation or cultural interest.