What types of signs typically have a rectangular shape?

Regulatory signs, including speed limits, are typically rectangular in shape. This shape is used to convey important rules and regulations that drivers must follow to ensure safety and compliance on the road. The rectangular design allows for clear and easy reading of the information, making it straightforward for drivers to understand what is required of them.

In contrast, warning signs, which alert drivers to potential hazards ahead, often take on a diamond shape for visibility and to distinguish them from regulatory signs. Yield signs, which indicate to drivers that they must yield to oncoming traffic, are usually shaped like triangles. Railroad signs are typically round or have specific shapes designed to alert drivers to railroad crossings. These distinct shapes help convey the nature and urgency of the information presented to drivers.