What is the name of the X-shaped sign posted at railroad grade crossings to warn drivers? Crossbuck. A crossbuck is the X-shaped traffic sign used to mark a level railway crossing.
The name comes from the sign’s resemblance to crossed wooden beams. In the United States, the two white slats traditionally carry the words “RAILROAD” and “CROSSING” in black lettering, and the sign is mounted on a pole at the crossing. A supplemental plaque may state how many tracks road users must cross.
A crossbuck is often combined with flashing lights, bells, gates, or pavement markings, but it remains a distinct sign rather than a nickname for the entire warning system. “Wig-wag” refers to a type of railroad warning signal, not the X-shaped board. Designs vary internationally: some countries use red-edged or yellow crossbucks, while the American version is generally white with black text. The sign warns of the crossing itself; drivers must still obey active lights, gates, and posted stopping rules.