Two separate groups consisting of both long-haul (N=184) and short-haul (N=
133) truck drivers were surveyed to examine the frequency of driver sleepin
ess-related problems at work during the previous three months and to assess
the incidence of sleep apnea syndrome symptoms. We also aimed to identify
factors likely to predict self-reported difficulties in staying alert in wo
rk driving, dozing off (sometimes referred to as microsleeps) at the wheel
and near misses.
The responses suggest that for approximately 13% of the long-haul drivers t
he mean driving time per shift exceeded the EEC regulation. About 40% of th
e long-haul drivers and 21% of the short-haul drivers reported having probl
ems in staying alert on at least 20% of their drives. Over 20% of the long-
haul drivers also reported having dozed off at least twice while driving. N
ear misses due to dozing off had occurred in 17% of these drivers. Factors
indicating sleep apnea syndrome occurred in only about 4% of the long-haul
drivers and in only two short-haul drivers. Work and individual related fac
tors as well as factors indicating sleep apnea syndrome contributed only sl
ightly to predicting driver sleepiness-related problems.
This suggests that driver sleepiness-related problems tend to be shared by
many of the professional drivers, rather than being a "specific" and perman
ent problem for a smaller portion of drivers. However, difficulties in slee
p patterns, such as having difficulty falling asleep, were infrequent.