Publication

Train drivers depend on surrounding systems of supporting organisational and technical factors to help them pass signals safely. We identify gaps in these systems by analysing ten hazardous signal approach incidents using a method for the selection and classification of error antecedents. Systematic aggregation of antecedent chains shows that hazardous approach situations are characterised by unusual conditions (excessive task demands or poorly salient signals) which increase the chance that drivers will employ inappropriate routine expectations about signal aspects. In a separate survey we find that 83 % of the drivers themselves rate the 'danger of developing assumptions based on routine' as worthy of investigation. We recommend that the organisation finds ways to challenge the establishment of cognitive schemas by drivers exposed repeatedly to unchanging signal aspects. Technical and other organisational recommendations are also given. Further development of the analytical method used is discussed.