ACCIDENTS caused by drivers falling asleep at the wheel are not simply due to spending excessive hours driving, according to scientific research. Responding to an appeal for guidance on how far an employee should be expected to drive in a day and whether driving at night or day was safer, Professor Jim Horne, director of the Sleep Research Centre at Loughborough University, said there were no 'hard and fast rules'.

But, he told the Royal Society for the Prevention of Accidents' 'Safety and Health at Work' congress: 'Much more attention should be given to how much sleep a person has had the night before and also in avoiding the times when the body becomes naturally tired, at between 5-7am and the middle of the afternoon.' He also said there was no evidence that driving at night is any more dangerous than in the day.