Factors associated with falling asleep at the wheel among long-distance truck drivers

Data on the prevalence and hypothesized predictors of falling asleep while driving were gathered through face-to-face interviews with 593 long-distanc e truck drivers randomly selected at public and private rest areas and rout ine roadside truck safety inspections. Hypothesized predictor variables rel ated to drivers' typical work and rest patterns, extent of daytime and nigh t-time drowsiness, symptoms of sleep disorder, measures of driving exposure , and demographic characteristics. A sizeable proportion of long-distance t ruck drivers reported falling asleep at the wheel of the truck: 47.1% of th e survey respondents had ever fallen asleep at the wheel of a truck, and 25 .4% had fallen asleep at the wheel in the past year. Factor analysis reduce d the large set of predictors to six underlying, independent factors: great er daytime sleepiness; more arduous schedules, with more hours of work and fewer hours off-duty; older, more experienced drivers; shorter, poorer slee p on road; symptoms of sleep disorder; and greater tendency to night-time d rowsy driving. Based on multivariate logistic regression, all six factors w ere predictive of self-reported falling asleep at the wheel. Falling asleep was also associated with not having been alerted by driving over shoulder rumble strips. The results suggest that countermeasures that limit drivers' work hours and enable drivers to get adequate rest and that identify drive rs with sleep disorders are appropriate methods to reduce sleepiness-relate d driving by truck drivers. (C) 2000 Elsevier Science Ltd. All rights reser ved.