Some effects of 8- vs. 10-hour work schedules on the test performance/alertness of air traffic control specialists

Abstract

A 10 h 4 d rotating shift schedule worked by some Air Traffic Control Specialists (ATCSs) was compared to the more traditional 8 h 2-2-1 rapidly rotating schedule. Measures of performance and alertness were obtained from a group of 52 ATCS at an en route ATC center on tasks in the NIOSH fatigue test battery. Additional information on sleep patterns, mood, and somatic complaints was also gathered. Results confirm that tests comprising the NIOSH battery are sensitive to fatigue and diurnal variations associated with a rotating shift schedule. Test performance of ATCSs on the 10 h shift did not differ from those on the 8 h schedule for any of the parameters, when comparing the initial 4 d of the work week. Test performance was notably poorer on the night shift that occurred on the final (fifth) day of the 2-2-1 8 h schedule. For both schedules, there was evidence of changes in alertness on some of the NIOSH performance measures within work days and across days of the week. Changes in test performance and mood ratings corresponded to the decline in self-reported sleep time across the work week. Relevance to industry The increased emphasis on compressed work weeks within industry and other settings has raised a number of issues concerning how longer work days impact sleep, fatigue, mood, and performance. There have been relatively few attempts to systematically utilize field studies to gather relevant data so that managers have a scientific basis for decision-making. This study is one example of an approach to developing a more effective data base for decision-making regarding both a rapidly rotating shift schedule and a compressed work schedule.