Fulfill a Need.

Signs are essential where special regulations apply at specific places or times, or where hazards are not self-evident. They are also needed to give information on highway routes, directions, destinations, and points of interest.

Command Attention.

Signs should be placed within the viewer’s cone of vision and positioned with respect to the point, object, or situation to which it applies so that it aids in conveying the proper meaning.

Convey a Clear, Simple Meaning.

A highway sign must be legible to those for whom it is intended. Legibility includes high visibility, adequate size lettering, and a short legend for quick comprehension by drivers approaching the sign at high speeds. To aid prompt recognition, standardized colors and shapes are specified for different classes of traffic signs.

Command the Respect of Road Users.

Signs should be clean, legible, and properly mounted. In addition to physical maintenance, functional maintenance is required to adjust needed signs to current conditions and remove unnecessary signs.

Give Adequate Time for Proper Response.

Signs should be located far enough in advance of a condition so that motorists have enough time to properly respond to the message. If signs are located too far from the condition, motorists may forget the action that may be required by the time they approach the condition.