What does a circular traffic sign with a red border indicate?

A circular traffic sign with a red border is recognized as a regulatory sign, specifically indicating prohibitions or mandatory actions that must be followed by drivers. The red color and circular shape universally convey that compliance with the sign is necessary for safe driving. These signs often communicate restrictions such as "No Entry," "No U-Turn," or various other regulations designed to maintain order and safety on the road.

In contrast, warning signs typically utilize different shapes, such as diamonds, and may not feature a red border. Recreational area signs have distinctive designs that do not conform to regulatory formats, and speed limit changes are usually denoted by rectangular signs, not circular ones with red borders. Understanding the meaning of these signs is crucial for safe driving and adherence to traffic laws.