What term describes a sign, signal, or device erected to notify traffic of railroad tracks or an approaching train?

The term "railroad sign or signal" specifically identifies the signs and signals that are put in place to alert drivers and pedestrians about the presence of railroad tracks or an oncoming train. These signs and signals play a critical role in traffic safety, especially at crossings where vehicles and trains may come into conflict. They provide vital information regarding the proximity of a train to the crossing, signaling to road users to proceed with caution or to stop entirely.

While terms like "traffic control device" encompass a broader category of items used to manage vehicular and pedestrian movement, and "warning signal" can refer to various types of alerts, neither are as specific as "railroad sign or signal." The term "safety marker" could also refer to different types of markers used for various safety purposes, but again, it is not exclusively associated with railroads. Therefore, “railroad sign or signal” is the most accurate choice for describing the device intended for notifying traffic of railroad tracks or an approaching train.