Searle, B., Macquarie University and Bright, J., University of New South Wales, Australia
This presentation reports two experimental studies in which models of occupational stress (primarily Karasek's 1979 Job Strain model) were tested using computer-based driving simulators. In both studies, participants experienced high or low levels of task demands and control. Reports of strain, satisfaction and perceived performance were measured before and after each task, and driving performance was measured throughout the tasks. The first experiment used desktop computer apparatus to simulate a regular car driving task. Driving demands were manipulated by varying traffic levels and control was manipulated using a speed-sensitive siren to enforce speed limits. While the study showed no effect of task conditions on strain, there was a correlation between demands and post-task reports of stress, and task conditions did influence driving behaviour. The limited realism of the simulation may explain why more unsafe driving was observed in conditions of greater task control. The second experiment used more realistic and sophisticated simulation apparatus to simulate a bus driving task. Driving demands were manipulated by varying traffic levels, lane obstacles and the need to set down passengers. Control was manipulated using regulations about the manner in which the driver responded to passenger needs. Higher demands led to increased stress in the bus driver simulation, but lower control did not have the same effect. Task satisfaction was greater under low demand conditions in both studies.