Sleepiness and driving: the experience of heavy goods vehicle drivers in the UK.

An interview survey of 996 heavy goods vehicle (HGV) drivers was undertaken. It was designed to investigate the relationship between HGV drivers' accidents, daytime sleepiness (measured using the Epworth Sleepiness Scale) and other relevant physical characteristics. The drivers were sampled randomly at motorway service areas. The average age was 41.4 y (SD 10.5), they drove an average of 69700 miles annually (SD 36120), and their average score on the Epworth daytime sleepiness scale was 5.65 (SD 3.31). They reported an average accident liability of 0.26 accidents in a 3-y recall period. Drivers who reported snoring regularly whilst sleeping at night or who were obese or who had a noticeably large collar size had higher accident liabilities than those not exhibiting these characteristics. Accident liability increased with increasing scores on the Epworth daytime sleepiness scale. These findings suggest that further investigation of the mechanisms behind the higher accident rates of some categories of HGV drivers would be justified in the interests of road safety.