Title

An investigation of sleep and fatigue in transit bus operators on different work schedules

Date of Completion

January 2002

Keywords

Health Sciences, Occupational Health and Safety|Psychology, Industrial|Transportation

Degree

Ph.D.

Abstract

The present study investigated differences in self-reported sleep length and aspects of fatigue for a sample of transit bus operators in the northeastern United States who were working split (two periods of work within one day) and straight (non-split) shift schedules. A written survey was designed to retrospectively assess the relationships among driver work schedules, reports of workday and days off sleep duration, and before- and after-work measures of tiredness, alertness, and mental exhaustion. A total of 102 operators provided data that were usable for the purposes of this research, where the sample obtained was representative of proportion of split/straight shift workers at the agency. ^ Results demonstrated expected relationships between reports of sleep length and before/after-work measures of fatigue. Among all operators, reports of workday sleep length were shorter than those for days off sleep length. A between-group analysis showed that split shift operators reported less sleep on workdays than straight shift operators. Across shift groups, before-work reports of tiredness and frequency of experiencing mental exhaustion were lower than reports made for after work. Conversely, levels of alertness were shown to be higher before work than after work. Contrary to expectations, nonsignificant differences were found between the shift groups for measures of tiredness and alertness. As hypothesized, split shift operators reported overall more frequent experiences with mental exhaustion when compared to the straight shift group. ^ As a pioneering effort in this area of research in the United States, the current investigation provided a solid basis for further study of the relationships among transit work scheduling practices, duration of sleep, and measures that subjectively assessed related measures of fatigue. Expected findings were evidenced for between-measure (within-subjects) relationships, but results of between-group analyses were less conclusive. For the current sample, differences between operators on straight and split shift schedules suggested that working twice within one day might be a disruptive schedule arrangement that impacts the amount of obtained sleep. Modest support was also demonstrated for the notion that split shift schedules, despite a break between work periods, are associated with a greater frequency of experiencing mental exhaustion than straight shifts. ^