Which sign indicates a railroad crossing?

The sign that indicates a railroad crossing is a round sign. This type of sign is specifically used to alert drivers that they are approaching a railroad crossing where they should be prepared to stop and look for trains. The round shape is universally recognized for this purpose and helps to capture the attention of drivers, signaling them to take caution.

Other signs serve different purposes; for example, the octagon-shaped sign is used solely for stop signs, while a triangle sign indicates yield. The diamond-shaped sign warns about upcoming hazards or changes in the road but does not specifically indicate a railroad crossing. Understanding these shapes is essential for safe driving and proper recognition of road signs.