The Effect of Locomotive Horn Characteristics on Motorist Detection

Previous research examining locomotive train horns has suggested that certain characteristics, such as the number of flutes used and the frequency components of flutes, may enhance the effectiveness of the horn as a warning device. The current research sought to examine these findings by using recordings of standard train horns that varied in their sound characteristics. A signal detection procedure was used in which participants were asked to resp ond when they noticed a locomotive horn played through a background of in -car noise. Participants were also simultaneously engaged in a visual tracking task in order to impose additional attentional demands similar to those encountered by a motorist. Results of the study are largely consistent with previous tests of locomotive train horn efficacy; however, the effects of isolated characteristics in real horns appear to be interactive rather than additive. Additional findings also suggest that detection may also be dependent on whether the demands of driving and distractions leave sufficient attention left to detect and react to the train horn. Results are discussed in terms of implications for motorist safety and design of locomotive horns.