A diamond-shaped traffic sign is usually a warning of an impending hazard coming up on the road, such as a sharp curve ahead, traffic merging, or deer crossing. These signs are most commonly yellow to alert drivers that there are conditions ahead which require a driver to be extra cautious to avoid a potential accident.
To make driving easier to understand for every driver on the road, road signs use a uniform method to alert drivers of different situations. These signs help reduce the number of accidents that occur on a road and can let drivers know ahead of time that there are issues or attractions coming up on a particular road. Throughout the United States, different colors and shapes of signs signal events in a uniform way.
Octagonal-shaped signs always signal that a driver will need to stop. Signs that are upside-down triangles signal that drivers need to yield to other drivers on the road. Pennant signs signal no passing zones, and pentagon signs warn of school zones ahead. A railroad is present if a driver sees a round sign, and rectangular signs let drivers know of traffic regulations as well as attraction information.
The color of a sign also affects what it means. A sign that is red always means stop, while a yellow sign signals that a driver needs to slow down and be cautious. Blue and brown signs show information to drivers on the road.