Chapter 2: Sign LocationAnchor: #i999602
Section 1: OverviewAnchor: #i999607
Requirements of Effective Signs
To be effective, a traffic control device should meet the following five basic requirements:
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- 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. Anchor: #UDENWKJX
- 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. Anchor: #DFWVEALB
- 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. Anchor: #VSIHBMCI
- 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. Anchor: #MOCYWXHC
- 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.
The following five basic considerations are used to ensure that the above requirements are met:
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- Design. Detailed drawings of standard signs and alphabets are shown in Standard Highway Sign Designs for Texas (SHSD). Anchor: #NGRBAQYE
- Placement. Signs should be appropriately positioned with respect to the locations, objects, or situations that they apply to. Anchor: #WWFTMBWY
- Operation. Regulatory, warning, and guide signs must be retroreflective to show the same shape and similar color both day and night. Anchor: #MSDBVRAF
- Maintenance. All traffic signs should be kept properly positioned and legible, and should have adequate retroreflectivity. Anchor: #YNXIQBWC
- Uniformity. Uniformity of signs aids recognition and understanding, thereby reducing perception and reaction time and simplifying the road user’s tasks.
The Texas Manual on Uniform Traffic Control Devices (TMUTCD) provides information and requirements for the location and spacing of signs (including a detailed discussion of the foregoing requirements in Chapter 2A). Some sign locations are more exactly defined than others. The TMUTCD should be consulted to determine sign location, color, text, and the rationale for using various signs. Part 2 of the TMUTCD, “Signs,” provides general information on this subject.
TxDOT’s Sign Crew Field Book (SCFB) provides additional guidelines surpassing the minimum guidelines listed in the TMUTCD for sign assemblies and sign placement.