Shift work, sleepiness and long distance driving

A structured interview was used to collect data from 1579 passenger vehicle drivers over a 10-week period. Approximately 11% of these drivers were shift workers (SW) who had completed night shift and the balance were non-shift workers (NSW). The mean one-way driving distance was 211 km (SD = 84) and 213 km (SD = 162) for SW and NSW respectively. The majority of SW (76%) did not plan to take a driving break and some intended driving up to 600 km. SW reported taking approximately 6.5 h of sleep the day before the drive compared to NSW who had a full nights sleep. Mean sleepiness ratings based on the Karolinska Sleepiness Scale (KSS) suggested SW were significantly more sleepy (M = 4.64) than NSW (M = 2.98). Approximately 19% of SW were classified with severe sleepiness (KSS ⩾ 7) compared to 1% of NSW and this suggested SW had a greater incidence of safety relevant sleepiness. Severe sleepiness has been linked to driving impairments and is therefore, of concern for the safety of the individual and the wider community.