Investigating driver fatigue in truck crashes : trial of a systematic methodology

Abstract Methods for investigating driver fatigue are not standardised, and estimates of the proportion of truck crashes involving fatigue vary widely. For 13 months, an anonymous questionnaire was distributed to truck drivers involved in crashes in New Zealand, seeking information on sleep habits, a sleep and duty history for 72 h prior to the crash, and the driver’s comments about the crash. The 130 completed questionnaires that could be matched to an official crash report were a representative sample (25.4%) of the 511 official crash reports for the study period. The respondents were mostly (98%) male, with a median age of 40 years (range 20–70 years). As a group, they reported better sleep and lower sleepiness (Epworth Sleepiness Score) than a large random sample of men aged 30–60 years. At the time of the crash, 10.8% of drivers had at least two of the following physiological risk factors for fatigue: continuously awake >12 h;