What shape is a Railroad Advance Warning sign?

A Railroad Advance Warning sign is designed to alert drivers about the upcoming railroad crossing. The correct shape of this sign is round, featuring black lettering on a yellow background. This color scheme is critical; yellow indicates caution, and the round shape is universally recognized for warning signs, ensuring that drivers are made aware of potential hazards in advance.

Other shapes and colors serve different purposes: for instance, square signs typically denote regulatory information, triangular shapes are reserved for yield signs, and pentagonal signs indicate school zones. By using a round shape and a bright yellow background, the railroad advance warning sign effectively captures the attention of drivers, promoting safety on the roadways.