Shapes impact our brain differently and are important to traffic safety. One way we recognize traffic signs is by their shape and each basic shape has a meaning. Knowing signs by their appearance helps adjust your driving by conveying information that you can comprehend and react to quickly even at a distance or if visibility is poor.
Sign shapes help stream-line the flow of traffic and are uniform across the U.S. An octagon is a shape used in traffic signs to notify or alarm drivers. The message: You’re going to need to take action.
Did you know that the greater the number of sides on a sign, the more critical the message? How many knew that fact? A diamond or triangle shape is for caution. Oval and circles send a message of comfort and lastly, squares and rectangles illicit familiarity.
Here are some specific sign shapes and their meanings:
- An octagon signals the need to stop
- An upside down triangle always means “yield”
- A diamond is used for warning signs
- A pennant warns of “no passing zones”
- A circle is a railroad advance warning
- A pentagon signals a school zone or school crossing zone
- Horizontal/rectangle signs typically provide guidance to drivers
- Vertical/rectangle signs usually serve as regulatory notices
- A trapezoid is used for recreational area guide signs and National Forest route markers
- Route signs can have different shapes but the Interstate is a cut-out shield
Our brains process shapes in different ways and each traffic sign shape communicates a different message. Knowing the shapes and their meanings can keep you and your employees safe on the road. This information would be great for you to share as a safety talk.
— Lisa Robinson is a senior program manager with the National Safety Council