Union Pacific is one of the largest freight railroads in the United States, and its diesel locomotives use multi-chime air horns to warn vehicles and pedestrians at grade crossings. Recordings of individual units like 4416 circulate among railfans who document specific engines by number, horn tone and location. This short blast was shared on soundboards for train enthusiasts, then picked up by video editors needing an authentic American train horn without recording one themselves. It remains popular because the tone is unmistakably railroad, not a generic synthesized horn effect.