Conclusions

• Based on American data, over one-third of the adult population has impaired functioning due to sleep loss during one or more days each month
• Surveys suggest that over half of all drivers drive while being drowsy at least once a year. Actually nodding off or falling asleep behind the wheel within the last year occurs for a sizeable proportion of the populations (range 10% up to 40%).
• Amongst young drivers, driving while drowsy is quite common due to lifestyle factors. Adolescents need more sleep than adults and fatigue may affect youngsters more than adults.
• Most professional drivers and shift workers have to cope with fatigued driving on a frequent basis due to work-related factors. According to surveys, half of professional drivers take less than normal sleep time before a long-distance trip
• Even the more acute stages of fatigue, e.g. dozing off behind the wheel, happen at least once a year for a considerable proportion of all professional drivers.