Optimising train drivers’ use of the horn to bring safety and driver workload benefits
The rules for sounding the train horn varied depending on the situation. This could be difficult for drivers to remember.
There are multiple scenarios where the Rule Book requires the driver to sound the train horn. In high-stress situations, drivers could become confused about exactly how the warning horn should be sounded in a given scenario.
Furthermore, decisions on the correct use of the warning horn were previously based on driver judgement, route knowledge, and experience. This left room for uncertainty and inconsistency.
We used findings from two research projects to complete this work: ‘Relationship between train horn test measurements and perceived sound levels on the track’ (T1205) and ‘Optimising drivers’ use of audible warnings’ (T1273).
T1205 looked at the factors that affect the sound transmission of train horns. It also explored how track workers hear them. T1273 gave suggestions on how to optimise the requirements for the use of the train horn.
We applied these findings to simplify and standardise the rules for using the train horn and tones.
A table in section 48 of GERT8000-TW1 is the main reference to these rules. It lists all scenarios in which a warning sound is required. We also expanded the instructions throughout the Rule Book to include the actual sound to be used, mirroring module TW1.
These Rule Book changes are expected to improve safety and driver workload. Specifically, they will improve driver recall and situational awareness in high-stress situations and improve their understanding of which warning horn sound is needed for the situation.
This, in turn, is expected to contribute to a reduction in the number of incidents and near misses involving track workers, level crossing users, and others.
In addition, consistent use of the warning horn has the potential to reduce delays caused by incidents.
The project’s total estimated benefits to the industry are over £450,000 over 5 years.