Locomotive Horn Evaluation: Effectiveness at Operating Speeds

This study assessed the placement and sound characteristics of locomotive horns. Its objective was to provide recommendations to ensure adequate warning for safety reasons and to address excessive loudness complaints from crews and from residents near tracks.

The scope of work involved laboratory investigations of desirable warning characteristics, field measurements of the influence of horn position on its effectiveness at operating speeds, and an in-service assessment of alternative horns. Safety effectiveness considerations included pedestrians/trespassers, drivers stopped at grade crossings, and drivers approaching grade crossings.

Recommendations are made to reposition horns in new-build locomotives and to add emergency-only or two-level horns at the front of some models of existing locomotives.