A FIELD-STUDY OF STRESS AND FATIGUE IN LONG-DISTANCE BUS DRIVERS

Psychophysiological changes during long-distance driving may be associ ated with driving fatigue and morbidity. Measures of stress and arousa l, including heart rate, blood pressure, catecholamines, cortisol, sta te anxiety, and self-ratings of stress and arousal were collected from 10 long-distance bus drivers during 12-hour driving shifts and at mat ched times on nondriving rest days. Cardiovascular and catecholamine d ata were elevated across the entire work day, compared with rest days. Self-reported stress and state anxiety were elevated only at the pres hift measure, and these elevations were interpreted as the result of a nticipatory anxiety and additional work demands at the beginning of th e shift. Decelerating activation from the 9th so the 12th hours of dri ving were reflected in slower heart rate and lower subjective arousal ratings. Suggested explanations for these findings are that drivers ex perience a release of tension when they anticipate the end of the shif t and therefore deactivation is a signal or precursor to the onset of fatigue in physiological adjustment mechanisms.