What type of signs are yellow and diamond-shaped, with black lettering or symbols?

Yellow, diamond-shaped signs with black lettering or symbols are classified as warning signs. These signs are specifically designed to alert drivers to potential hazards or changes in road conditions ahead. The diamond shape is universally recognized as a warning sign, and the bright yellow color makes them highly visible, helping to capture a driver's attention.

For instance, a yellow diamond sign might indicate a sharp turn, pedestrian crossing, or construction zone, allowing drivers to prepare for any necessary actions, such as reducing speed or being more cautious. This proactive approach to traffic safety is crucial because it helps prevent accidents by giving drivers advanced notice of potential risks.

In contrast, regulatory signs provide mandatory instructions that must be followed, informational signs offer general information (like mileage or directions), and guide signs typically provide navigation assistance. These different sign types serve distinct purposes in managing traffic flow and ensuring safety on the roads.