Abstract
Experimental analysis is reported on signal confirmation errors by railway drivers on the occasion of a train's departure. Actual operation to start a train was simulated in the laboratory. Subjects were instructed to verify “clear” signal prior to departure time and reconfirm them before they begin the starting operation after a sign of departure is given with a pilot lamp or a tone. A secondary task such as memorizing figures was imposed on the subjects in order to distract their attention. Reaction time, error rates, and signal confirmation behavior recorded on VTR were analysed, comparing various types of departure signs. The results were as follows: (1) Subjects tended to miss the signal if they did not immediately notice the sign. (2) Preparatory confirmation was easily omitted owing to the distractor. (3) Probability of prior confirmation was improved by changing location or modality of the sign. (4) It was also effective to place a written warning on a pilot lamp. (5) The operation was sometimes triggered the sign even if the subjects noticed lights. (6) Automatic reaction without confirmation occurred when the operator was devoted to the secondary task. Based on experimental analysis, countermeasures were discussed.
