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Essential Elements of a Warning Sign

December 4, 2018

Wherever danger exists on your property, there should be a warning sign for motorists and pedestrians. Many times warning signs are placed in areas where traffic is safer at a slow speed. Here are important points to keep in mind if you decide to post these signs in your area.

Meeting Federal Standards

All warnings signs on American roads must conform to standards set by the federal government, as published by the Federal Highway Administration’s “Standard Highway Signs” book. Here are the primary requirements for warning signs:

  • Diamond-shaped
  • Yellow or fluorescent yellow-green background
  • Black legend and border
  • May contain image

Images for warning signs span a wide variety from pedestrians to bicyclists to school buses. The wording on signs is left to be developed by state and local transportation officials. Some of the most common uses of warning signs accompany people working in temporary traffic control zones. Sign sizes should be conventional for most roads, except for freeways and expressways, which use larger signs for better visibility.

Familiar Warning Symbols

Typical warning signs are based on symbols that represent road conditions familiar to drivers. Arrows pointing both ways, for example, indicate two-way traffic. A cross means there is an intersection approaching in which all vehicles have traffic controls. A “T” symbol indicates that the road will end with a perpendicular road, meaning the driver must turn left or right. A “Y” symbol indicates that the road will intersect with another in a diagonal manner.

Warning Sign Placement

Road signs are placed according to Perception, Identification, Emotion and Volition (PIEV) time. This calculation comprises the total amount of time it takes the average driver to recognize and respond to a warning sign. PIEV time is measured in seconds and can last over six seconds for signs that require driver judgment. A series of warning signs with different messages relating to the same conditions should be placed in a way that the driver has time to clearly comprehend all messages. This placement should be evaluated periodically for effectiveness for both day and night driving.

The most useful warning signs are the ones that associate with a specific location, such as a road closing or a fork in the road. Warning signs with speed limits around sharp curves are helpful at keeping drivers from losing control. Winding roads with a series of sharp curves need multiple warning signs to help guide drivers and remind them to reduce speed.

Ideally, the sign is placed where the driver has a chance to make a decision to avoid driving extra miles. If a road comes to a dead end, for example, it’s best to warn the driver at the intersection instead of near the end of the road. If the road turns into dirt and rocks in one mile, the motorist should be alerted so that he or she can decide if they want to accept the risks of unpaved roads. If a road narrows from 3 lanes to one lane, a warning sign helps the driver prepare in situations with heavy traffic

Contact Zumar for Effective Warning Signs

Warning signs are easy to spot for drivers due to their bright yellow or yellow-green color, as they convey important information that keeps roads safe. For more information about warning signs, call Zumar at our Arizona, California or Washington location.

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